Rokinon/Samyang 135mm discussion

[hazy copper]

I wonder if I can design my own hm

[chilly ingot]

are you going to need a new lens to design a new print?

[cosmic marlin]

u must clean ur roki everyday no way its just naturally spotless

[hazy copper]

I might have some I can reuse

[hazy copper]

Nope. I just care for it

[hazy copper]

F/2 vs F/2.4 vs F/2.8 on roki. It gets worse at F/4 but im too lazy to test the in betweens.

[civic mirage]

Do those FWHM figures account for any CA that may be present at f2?

To be honest f2.4 looks like it's a nice sweet spot

[hazy copper]

Trying to figure it out. I believe so. But it measures what it calls a star so the CA shouldn’t affect it. I also get no CA at f/2 so yk.

[fallow stirrup]

The Roki is asleep waiting for the perfect clear night

[solid raptor]

The beast slumbers

[cosmic marlin]

Clean your keyboard

[chilly ingot]

where cam

[chilly ingot]

still no new cam

[chilly ingot]

monday marks 5weeks since cam order

[uneven compass]

What cam and where did you get it?

[chilly ingot]

zwo asi585mc from astro-art

[uneven compass]

Astro art?

Or astro Mart?

[chilly ingot]

its finnish store. competetive pricing and sometimes better than mainland eu

it was noted as backorder with 2-3weeks but the dockworkers union had a 2 week strike

so there is a pile of stuff they have to clear now

[uneven compass]

Ah well there you go

[chilly ingot]

they launched a online store for norway so whe whole site was -5% off

i backordered it to get it for the discount

mistake

[worthy grove]

So after a frustrating 2 weeks of solid cloud and rain I had half an hour of clear skies last night to test the uranus-c/roki135 combo with the l-extreme and it turns out filters under B7 skies are a game changer

So the first is the 2.5hr stack with no filters and the second is the 14mins of data I managed before the clouds ended the session

In just 14 mins of data there was so much more nebulosity on display ! shame the star halos are pretty prominent though!

I had to move from 90s exposure to 120s which is probably a bit of push for the alt-az gti unguided too

but for anyone wondering how the roki 135 performs with the l-extreme, there ya go

[chilly ingot]

Yeah dual nb is great

I didnt get the l-extreme just for the risk of getting a sample that does halo’s

like Cuiv has one that does no halo’s

i went with IDAS NBZ

[worthy grove]

Yeah you can see the halos on mine are quite extreme

[chilly ingot]

I would return that filter

[worthy grove]

I think its run of the mill for that filter isnt it? Not seen that its a batch error or anything?

[short charm]

Also the bandpass shift from the faster optics hurts the l-extreme a lot. It is sample dependant, but you ideally want a wider bandpass due to that shift

[worthy grove]

Well aside from the halos (which like Cuiv don't really bother me) I was pretty impressed, i have to say

[worthy grove]

Its quite strange which starts have halos too, not necessarily all the brightest ones, odd

[chilly ingot]

https://www.astroshop.eu/astronomical-cameras/zwo-camera-asi-585-mc-color/p,75716

damn thats cheap bro's

[worthy grove]

Not as cheap as I got the Uranus-c though

[chilly ingot]

how much was that

[worthy grove]

https://m.aliexpress.com/item/1005004330074646.html?spm=a2g0n.productlist.0.0.728bfvuPfvuP8I&browser_id=12c08d864b664e9a81dce9a323d551f3&aff_trace_key=&aff_platform=msite&m_page_id=h0h5hdmt1ucazeog186e68453af17c14ea4322cddf&gclid=&pdp_npi=3%40dis!GBP!457.18!329.17!!!!!%40211b88ef16789046766167029efa4f!12000028780673336!sea!UK!0&curPageLogUid=qXjdeRJmzJ3M&algo_pvid=bf0f8289-dc46-4239-ae6c-7456f4a5ed73

[chilly ingot]

its like 20€ more. it adjusts VAT for me

[worthy grove]

Ahh ok maybe a UK thing

[worthy grove]

I just noticed on my recent image that it appears there is some sort of tilt in the imaging train somewhere? Any ideas where and how i could address it..
At first I though it was star trailing due to the 2 min exposures unguided but looking in more detail it appears the stars towards the corners point outwards?
Do you reckon its the Roki or the camera sensor?

Would like to address it before I undertake my next session (if the clouds ever go away) when I hope to grab more that 14 mins of integration 😆

I didn't notice this training until I had the filter in my imaging train but that's probably because the star boat without a filter hid it somewhat ?

I assume you didn't ever get this problem @hazy copper ?

[hazy copper]

might be backspacing too

i normally have very slight tilt

[chilly ingot]

When corners are egg shaped towards middle, you dont have enough backspacing. Correct?

[worthy grove]

That makes sense, i dont have any backspacing.. need to get a 5-6mm spacer then assuming mine ends up the same as yours? You did warn me and i ignored you

It seems stupidly hard to find single spacers for some reason

[chilly ingot]

Well i have the luxury of zwo EOS filter draver that fits 17.5mm backspaced cameras. Player one is 12.5mm so you need 5mm t2 spacer?

[worthy grove]

I have the same filter drawer but its not enough

It reached infinty focus about 2/3 through the focus range

[chilly ingot]

Single spacers are expensive too. The svbony spacer set costs the same as single’s

[worthy grove]

OK ill look for that then.. T2 thats M48 right?

[chilly ingot]

isnt it 42mm? Double check

I cant remember rn. Im at work 😅

[worthy grove]

Ill check.. I think the uranus c is an M48 as is the zwo filter drawer. You got this sort of thing ? https://www.amazon.co.uk/Svbony-Extension-Adapter-Extending-Astrophotography/dp/B07S72HT9R/ref=sr_1_4?crid=1ALH2ZSV8BCOF&keywords=svbony+spacer&qid=1679059701&sprefix=svbony+spacer%2Caps%2C57&sr=8-4

[chilly ingot]

Think you mixed it with filter size

M42 is the camera side

[worthy grove]

Really? hmm ok ill take mine apart and measure to be sure 😂

[chilly ingot]

[hazy copper]

M42 on both

[worthy grove]

Yup cool

[hazy copper]

i need a like 6mm spacer to get mine right

i made a basic adjustable one lol

[worthy grove]

No ideas where I get 6mm from? Hopefully 5mm will be enough fix my stars? Then I just have to worry about the l-extreme halos!

Would be so much easier if I live in the middle of the Australian outback!

[hazy copper]

5mm should help.

[worthy grove]

I guess I could try and get hold of 2 3mm ones

I must get some anti seize paste too, I hear spacers are notorious for never coming apart!

[chilly ingot]

Or 5mm + 1mm shim

There are good spacer sets from FLO.

They sell two kinds if memory serves well

REMEMBER AFFILIATE LINKS

[worthy grove]

Yeah illl take a look and use the links

[chilly ingot]

@worthy grove oh yeah. I think getting a 5mm and shim set to backfocus for a thick filter

1/3 filter’s thickness to backfocus

[worthy grove]

Well the filter doesn't add to the image train as its in the filter drawer?

[chilly ingot]

Like my idas nbz is 2.5mm if i remember right. I added 0.8mm

[worthy grove]

why would it add thickness if its in a filter drawer though?

[chilly ingot]

If you have none installed. Then it does not.

but if you have something mounted in there. It does affect

[worthy grove]

Oh right, that doesnt really make sense though? The distance from sensor to lens is unchanged right? no matter if there is a filter in the drawer or not. Im missing something here

[chilly ingot]

Sensor to optics distance is not the same when abit of it is taken by a filter

@tender apex help

[worthy grove]

OK But If the distance is taken up by air vs filter glass that's where I dont quite get it, its the same distance but maybe the filter refracts the light slightly hence why you don't need as much?

Ill get 5mm plus shim as you suggest though as it will give me flexibility to experiment a bit

[chilly ingot]

For simple people like me, ”1/3 filter thickness is close enough to add”

[worthy grove]

That makes sense... Great explanation, thanks of persevering with me

It takes a bit of trial and error this does..

[chilly ingot]

might solve some headscratcing later

getting a shim set instead of just one is good

my filters are all different thickness

dhl express seems to be lightning fast

📫

ordered at like 3pm. got notified 30mins later delivery on monday

from germany

[worthy grove]

I have an amazon order on a 5mm one arriving tomorrow.. May have to make a cardboard shim until I get a proper one in the meantime

[chilly ingot]

or some stiff plastic

[worthy grove]

i imagine even the 5mm will vastly improve the stars in my image

[chilly ingot]

the diy garage shims are cut from coke cans with scissors

yeah i think the small shimming will affect the extreme corners most probably. not sure

[worthy grove]

well my backfocus is well off at the moment as I have no spacer at all just the lens adapter / filter drawer

[chilly ingot]

so few clear nights to test things. im one of those who need to see things work to understand 😄

[worthy grove]

Yeah clear nights are few and far between in the UK at the moment.
I didn't full understand back focus when i started, I just assumed if I can get focus it didn't matter, I didn't realise it would cause that odd tilt effect

[chilly ingot]

also i had problems with adjustable backfocus things. those great to figure it out. but getting it solid with the right spacers and shims are the way to go

when gear gets cold, its not as tight as it was indoors

the lockring in my william optics adjustable flattener was not enough for a stiff camera rotator

and i nipped it up good inside 😄

so i got some M54 shims to the flattener too

[tender apex]

Filters add 1/3rd there thickness to the focal plane distance

[fallow stirrup]

New image taken with the Rokinon

[worthy grove]

I think you have some dust on your lens 😂. Great image. Amazing detail. What area is it?

[hazy copper]

Chameleon cloud. near the SCP

[worthy grove]

Much better! This time managed 1hr of poor quality subs (basically was shooting all night and have taken ones where there were gaps between the clouds) Now with a 5mm spacer.

You can see I'm still not got enough back focus but waiting on a 1mm shim (although I do have a 7mm I may try)

[chilly ingot]

nice nice

does sub lenght matter on the halo?

also are you shooting wide open or clicked down?

[worthy grove]

doesn't seem to really, I had worse halos but have removed in this processing

I shot this at 2.4 I may see if wide open changes the halos at all, the star burst is quite prominent when stopped which may be a halo inducer? Not really had enough clear skies to experiment with yet

these were 2min subs, not bad for no guider!

Il post my data if you want to take a look? the halos are pretty ridiculous tbh but easy to remove

#1087047201995358350 message

[chilly ingot]

cant wait till clouds go away

[chilly ingot]

@hazy copper single bag setup major milestone

2sec sub out my window, 600stars

[worthy grove]

Looks superb! What camera are you using there?

[chilly ingot]

533mc

[worthy grove]

Nice. Look forward to seeing what it can do. Nice to have a guider as well

[chilly ingot]

One of those investments that carries over to other setups as is

[worthy grove]

Certainly does, Although I've been managing 2min subs that are solid on my az gti unguided

[chilly ingot]

i did 5min with 2.66”/px no worries. Only a test though

Seeing was good so guiding was solid

[worthy grove]

Nice 👍

[chilly ingot]

i didnt do that long subs with dslr. I was using a intervalometer with my hands frozen.

[worthy grove]

Ha. Yeah I remember those days

[chilly ingot]

No more though, asiair mini now. My aps-c cam was not supported by the little box. And the scopes flattener/reducer is limited to aps-c

I had the worst gear missmatch for a while

[worthy grove]

Yeah looks like a great upgrade. I'm rocking a mini pc and NINA rather than asiair

[chilly ingot]

got a add-on that mounts to the ring/handle. Its a redcat part but the maker printed one part custom to fit my lens

@worthy grove not my picture. But its the Pro Astro Gear black cat. I plan to get a eaf someday

Made the cog for focus ring custom size

[fallow stirrup]

Dam you got a good rig I want a rig like that

I want the ceres c for the guide cam and the Uranus c for the cam that’s my ideal future rig to save for

[chilly ingot]

The astrodynium or something like that ring system is better though

That rc51 ring blocks the aperture ring

[short charm]

Highly recommend astrodimium, its awesome

[chilly ingot]

I am an idiot for not getting that. It is the best mounting system for this lens

[uneven compass]

Just bought one lmao

And yeah it works beautifully

[short charm]

Honestly the big reason why I wanna get an eaf, just to have a nice enclosed focuser instead of my diy additions onto the shell

But if anyone needs the nema14 bracket files for the astrodimium shell, lmk!

[lone tendon]

👀

I made one but it was terrible

[worthy grove]

I wondered about printing it but its like £60 from flo

[short charm]

Can't say mine is any good lol, but at least it kinda works 😅

[lone tendon]

How does it fit on?

[short charm]

Just goes into the same spot as the eaf adapter from astrodimium, I just added a small bump to match the indent on the clamshell

I'd probably move the screw hole a bit more forwards if I had to reprint it

[lone tendon]

how do you stop it twisting around

thats my issue with my design currently

[short charm]

with that bump lol

At least I imagine that's what they're using the indent for

I'm not a good cad designer though, so it's probably not the best implementation still

[lone tendon]

Oh right, is that on the rings?

[cosmic marlin]

would u happen to have the ring set 3D print file thing ?

[short charm]

You mean this? https://astrodymium.com/products/astrodymium-rings-for-samyang-rokinon-135mm-f-2-lens

[short charm]

Yeah, looks like they updated the design though, and there's now 2 screw holes there instead of a hole and an indent, so not sure which version you have

[cosmic marlin]

Yep that’s the one

[short charm]

Yeah it's not really available for download and self printing 😅

[uneven compass]

Unless you're me

Then i tried printing it and it didn't work so well

[worthy grove]

I was going to give printing it a go. What was the issue? Maybe for £60 it's not worth it

[hazy copper]

i printed mine and its fine

https://www.printables.com/en/model/153157-openastrotech-samyangrokinon-135mm-cradle-with-foc

I use this but slightly modded.

mainly i used gopro screws to clamp it and a aluminium base plate

The GoPro nuts are melted in the plastic

I didn’t use any heated inserts apart from that

@cosmic marlin in case you are interested

if i was u i would avoid the heated inserts as much as possible.
i dont trust them enough

[cosmic marlin]

Wdym heated inserts ?

[hazy copper]

little bits of brass you melt in that hold a screw

[cosmic marlin]

don’t think I have any of those anyway 😄

[cosmic marlin]

It dosent have the guidescope mount thing on the top ?

[hazy copper]

you need to adapt it somehow.

maybe even zip ties lmao

[cosmic marlin]

I might have a screw that could fit that slotted hole thing, do u know how wide it is ?

[worthy grove]

I would have thought some sort of plastic cement or resin would be better ?

[hazy copper]

7mm

the underside has a recess which is 15mm so you could use a washer

[cosmic marlin]

hm maybe not able to then

[cosmic marlin]

Would it be bette to get Ryan to print it? Since his printer can printer stronger plastic (iirc) ?

[hazy copper]

postage would also be cheaper

and if your star party happens he could drop it off

[cosmic marlin]

Probably won’t be before my bd

[crimson goblet]

2nd try

I don't have my camera rn so I'll have to wait to see if it's a decent copy

[solid raptor]

Just look through it

[chilly ingot]

What is that

Cine lens but its not 135 and what mount?

Looks like EOS-M

[solid raptor]

50mm

[crimson goblet]

50mm Sony e mount

(yes I'm an imposter)

[chilly ingot]

Well, im calling the police

[cosmic marlin]

Snitch

[crimson goblet]

Alright I just tested it

It's... decent I guess

Definitely better than the first copy but even at f2.8 the coma is quite bad

I don't know if I keep it

It's decent enough...

[short charm]

I guess I had really good luck with my copy 😅

[chilly ingot]

well i can shoot at F2, same slight blue fringing towards middle on some stars. the F2 is absolute hell to keep in focus though

F2.8 feels nicer.

next time out ill do some astap testing for science

[cosmic marlin]

I haven’t needed to stop down mine

[crimson goblet]

Or I have bad luck 😅

LMC got his good copy at first try, Caphe got a bad copy, somebody I have forgot the name of got a good one on second try...

Looks like ~1/2

[hazy copper]

Seems to be 1/5 ish

For the 135 that is

[short charm]

You need an autofocuser then

[tardy epoch]

me lol, turns out my adapters have tlit though

5d mk ii the stars are round full frame

[short charm]

I shoot at f2.3 rn, got step down rings that bring me down to 58mm aperture over the 67mm, plus the stars are quite good there

And definitely also have adapter tilt 😦 and can't remove it with a better adapter cause they don't make it for mono. When I get a color cam again, I'ma get the proper adapter then though

Currently just shooting with my 60d that has slight tilt on the right, but it's barely noticeable

Plus can't fix it 😅

[crimson goblet]

Also Ill mainly use it with the uranus c, and with this sensor size the whole field is pretty sharp at f2.4 so yeah

Pretty good

[chilly ingot]

That and more stable temps

[crimson goblet]

Not good

Heavily cropped quick test on antares...

[gleaming flare]

untracked??

very good

[crimson goblet]

Literally 2 minutes of integration before sunset lol

[gleaming flare]

huhhhh

is it that bright

[crimson goblet]

But yes untracked

At f2.4 btw

[gleaming flare]

noww it makes sense

[crimson goblet]

The coma on the right side is

Uncropped

Dam I don't know if I should keep it

[chilly ingot]

1.8fwhm in my short stack.

One corner looked cursed.. 45% tilt

[crimson goblet]

I knocked my roki and now it's perfect

[tardy epoch]

its loose optics I swear

rokis are so odd some times

[short charm]

Percussive maintenance ftw!

[civic mirage]

Desperate times call for desperate measures

[solid raptor]

• nervously stares towards hammer *

[worthy grove]

I knocked mine when it was on my dslr camera (in normal photography mode) slung over my shoulder and clonked it on a door frame as I walked through, Mine seems to be optically great (I don't know if it was before i whacked it or not) 😂

[crimson goblet]

All of this is making me laugh so hard

[tardy epoch]

wait @twilit hound's changed as well

turns out all you need to do is b o n k

[short charm]

Actually though? You mean caphes roki is now a good one?

[chilly ingot]

ill bang the yesterdays tilt right off

[short charm]

Hmmmm, I may have hit mine too hard, any tips?

[twilit hound]

no it didnt

its still bad

[short charm]

Keep hitting

[twilit hound]

ass lens

[tardy epoch]

but what happened to they're alive and changing though lmao

[twilit hound]

It was just an illusion

[short charm]

That looks like backfocus dude

[twilit hound]

its not

[short charm]

Damn

[tardy epoch]

its backfocus of the internal elemets I'd say

[twilit hound]

I bought the EF version and use it on my 60D (EF)

its spaced properly its just the elements

I dont want to start this discussion again please, it just brings down my mood

im already in the middle of a 200 question exam that my parents are going to kill me for if I dont get an A

[tardy epoch]

all lenses move when focusing so bad backfocus isn't really a thing with this stupid lens

[tardy epoch]

sorry

[twilit hound]

you're fine

[short charm]

🤐

[twilit hound]

and real quick though

mine is more than just coma

it has really bad astigmatism

and it also has this really weird flaring on bright stars

@short charm @tardy epoch

[tardy epoch]

[twilit hound]

about as soft as a sponge too

[silent zealot]

that means you need 7.3 more hits

[fallow stirrup]

Oof I feel bad some of ur Roki pics are really good tho for the issues it has

[worthy grove]

Last nights effort! Needs more data (about 1hr50mins here) And I kind of missed with the dithering I had to crop the top a bit which was annoying

not really got the hang of this processing yet

It was a combo of siril/starnet and gimp

[chilly ingot]

When you are done imaging it, upload the stack to #1021002743080558642 and lets see what other nerds can do

[worthy grove]

Ive uploaded the latest stack just now

I really must get that extra 1mm spacer as I still need a tad more backfocus

[chilly ingot]

Removed my 0.8mm spacer since i discovered i has alot of tilt

My untracked test sub was like 15-20% tilt is astap image inspector in room temp

Tracked 60sec sub in -5c was 45% diagonal

idk what is going on

The spacer felt like it had a low spot

[fallow stirrup]

Chee

[worthy grove]

How do you analys your tilt?

I have a 5mm extension on now.. I do have a 7mm I could try but it may be too much? While i understand the physics of backpacking I still don't really understand how you precisely calculate how much is required for any particular setup

[chilly ingot]

I open a sub in ASTAP and select image analysis and click tilt inspection

I check several from the session

@worthy grove this was with my Z61 scope

some subs were 4-5%

[worthy grove]

Ill give that a try, I dont think i have ever used the ASTAP ui, I only use it for plate solving in NINA

[chilly ingot]

Im tempted to just get the M48 adapter for the roki and be done with all bayonet mounting

even adding a filter drawer now gives me the sweats

@worthy grove ill show you after work the abomination of a tilted sub with my roki

Over half the stars looked like the hubble variable nebula

[worthy grove]

I have to say I haven't had issues with mine so far

[chilly ingot]

Im pissed off really. Im gonna image with my scope for abit till i figure out something

[worthy grove]

Yeah it sounds tricky to debug, what camera are you using? Does the camera not have tilt correction you can use?

[chilly ingot]

I use the asi533mc

it screws on directly to the filter drawer so idk if there is room for a tilt plate

[worthy grove]

I see

[chilly ingot]

I think there are A4 papers i can print that has a bunch of white dots on a black background to image on a tripod

@worthy grove when did you get knighted as a nerd?

[worthy grove]

Last week i think

I have serious imposter syndrome 🙂

How does it even happen? (is there a high council meeting or something)?

[chilly ingot]

when i kick @gusty rock’s ass in the northern leo triplet competion. Ill be the 1st protostar with a trophy

Vote for me btw.

[worthy grove]

Ill take a look

[chilly ingot]

Its still open. End saturday i think. Then some days till its upto votes

[worthy grove]

What filter did you use for that in B8?!?

[chilly ingot]

just baader moon&sky glow or what ever its called

neodymium

@worthy grove

Moon pmuch super polluted 2/3 of my stack

Leo is around the cross

This gradient in livestack

[worthy grove]

Amazing you got such good detail with just that on 3hrs worth!

What were your sub lengths?

[chilly ingot]

30s

[worthy grove]

Great job!

[chilly ingot]

could have gone for more. But on 2nd night i was glad i didnt

[worthy grove]

Do you recommend that filter over a normal uv/ir one then?

[chilly ingot]

[chilly ingot]

Idk really. It is the least aggressive of the bunch

also thin. Just 1mm

Only adds 0.3mm to backspacing that is not alot at all

[worthy grove]

Since getting my dual narrowband filter which was a game changer (in both good and bad ways) I am thinking about filter purchase for broadband targets

[chilly ingot]

@worthy grove a broadband filter is a hot debate. Im gonna test some uv/ir cut sometime and same target with broadband filter

Got 2x trays for my filter drawer

[worthy grove]

Yeah I've heard some say dont bother and just stick with uv/ir and others say that something like the l-Pro is worth using... I guess it depends on your exact location and setup though

[chilly ingot]

The baader one i have is pretty much a l-pro with less cost

[worthy grove]

the one you used for this you mean?

[chilly ingot]

I have a mixed case of sodium lights and led’s

Yea

I think its great if i image over the buildings or over the railroad

But over the logistics center that had led’s its gonna be least effective

Some people in cloudy nights say the best filter is a gas, oil and cabin filter and drive to a darker place

[worthy grove]

Well my rig is a travel rig and I can drive to a b4 site in 30 mins so thats ultimately my aim but I want to get used to it before taking the travel plunge

[chilly ingot]

Same

I can cycle to a b4 spot in 20-25mins

want a better bag for it 1st

[chilly ingot]

Btw i was gonna shoot flats after imaging. Cold lens fogged up indoors right away. Lucky i had clean optics before and after imaging. I stacked with old flats i took day before and it was fine

No darks, only bias

[worthy grove]

Why dont you shoot your flats in situ?

[chilly ingot]

freezing my ass off and i just want to leave

i usually do em right away when im home

[worthy grove]

I have to say using the NINA flat wizard revolutionised this part of the process for me, I tell it to slew to zenith, put my £7 led panel over the top and then press the go button on the wizard and it takes 30 flats in seconds! Once you have configured the wizard once for your panel its a breeze

[chilly ingot]

Might setup that on my pc and use the ipad as a light

used my 600nits HDR monitor for it and sometimes the pad

The asiair flats looks weird

[worthy grove]

I used to use an ipad but I got worried about putting it on the top and also struggled to get the screen brightness consitent so went for a really cheap tracing panel on top of some copy paper. It works a treat. Never used (and probably never will) use the asiair so cant comment but Nina makes flats so easy

[chilly ingot]

Got decent ones with AV mode on my dslr to test histogram and then going manual with the settings faster or slower exposure

[gusty rock]

You sure will ^^"

[chilly ingot]

[twilit hound]

wait I just realized why are you not red nerd

[solid raptor]

Has anyone here photographed the elephant's trunk nebula?

[worthy grove]

Nope but I think I will in the summer as my winter targets disappear

Managed this with the roki the other day

[chilly ingot]

Got some tilt issues atm with my roki so ill finish the spring with scope

gonna image elephant’s trunk tonight

i guess the filter drawer is bad

i will adapt the roki to M48 and get a thread on drawer

[worthy grove]

Sounds like a good plan. What makes you think it's the filter drawer?

[chilly ingot]

Its reputation

might have been the 0.8mm shim

But idk. Had too many problems lately

https://www.firstlightoptics.com/adapters/astro-essentials-samyang-lens-to-m48-adapter.html

Bayonet mounts have springs inside and even a stiff cable pull can cause tilt maybe

[solid raptor]

Do u analyze it in astap?

[chilly ingot]

yeah.

i had mount problems too. but i want to measure the filter drawer

also it might just warp in the cold

cant remember my camera orientation anymore

[solid raptor]

Oh damn if that's bad then my tilt is terrible xD

[chilly ingot]

The cam im using is more sensitive

[solid raptor]

Hmm is the test image in nb?

Mine could also be caused by the clip in filter couldn't it?

[chilly ingot]

This tilt

[chilly ingot]

F3.2 i was getting red, magenta and blue starts

at wider apertures even the middle was cursed

with dual narrowband it got even worse

i increased backfocus now for like 1.5mm and at f2.8 the bottom is no longer super soft

[worthy grove]

Sorry you're having such a bad time with this! Have you managed to confirm that its not an issue with your lens but something else inh you imaging train?

[chilly ingot]

Ordered a tilt plate

[chilly ingot]

borrowed some digital calipers from work

seems to be 0.01 - 0.03 of tolerance in this adapter

low spot maybe 26.49 and high spot 26.53 give or take 0.01mm i dont trust these calipers enough

same sort of bumpyness in this 11mm T2 adapter in the cam but slightly less

measured my t2 spacers i got. these are absolute crap it seems 😄

[patent dove]

I'm planning on getting one of these lenses now, is the best way to get a good copy just to buy a new one and return them until its a good one? I want to be able to shoot at f/2 with APS-C

[uneven compass]

Yeah do that

[chilly ingot]

weeell. unless you buy a tested copy from someone. getting one from a shop with a no fuss return policy is a another way

getting one with tight stars at f2.8 is more realistic

[worthy grove]

I got mine from Amazon and it was fine. Maybe luck but I was unaware there were even issues with this lens

[short charm]

Also sometimes using stepdown rings allows you to get more aperture than with the aperture rings, mine is at f2.3 with the rings with no abberations, only tilt

I could really just shoot at f/2 with minimal issues as well

I just peep

[crimson goblet]

Got my first copy on Amazon and it was kinda bad, got a refund and I bought the 2nd one one mpb and it's decent enough

[chilly ingot]

I feel like imaging at f2 it is really sensitive to aligment

Sensor and pixel size will decrease or increase any errors

Like mine did decent subs with fullframe, but with 533mc its unusable

[short charm]

Well the adapters are quite bad unfortunately 😦

A lot of people say they really like the geoptik adapters, but I can't test it cause it doesn't have enough backfocus for a filterwheel

[viral raptor]

Might be able to get my hands on a used Roki tomorrow, it appears to be a very decent copy

[chilly ingot]

yeah and adding a filter drawer, then there is probably no room for tilt plate

i ordered the M48 bayonet replacement so i have a plan B, then i just need to figure out a way for 2" filters

[short charm]

You'll probably have to screw into the adapter

[chilly ingot]

there is not enough threads unless i remove the actual filters lockring

i could daisychain a bunch of stepup and stepdown adapters to fit it. that would cost bit too much

[chilly ingot]

tbh the dual nb filter is also tilt sensitive, when i took flats. one side is green and other is red in the flat 😄

im triggered that in my roki setup goddamn nothing works out of the box

[short charm]

I just accepted that I'ma use a DSLR with my roki and call it good lol

[chilly ingot]

yeah i should have bought the 2000D on sale

my aps-c mirrorless is more noisy and unsupported by asiair

[patent dove]

this is what I plan to do too so I can use the standard zwo filter drawer and an oag

[chilly ingot]

i saw a filter drawer that had a built in OAG

https://www.firstlightoptics.com/filter-wheels/antlia-off-axis-guider-and-filter-drawer-assembly.html

37.5mm thick. so theres 6.5mm left to space out

[short charm]

That's 250 euro though...

[chilly ingot]

how much is filter drawer + oag + helical focuser for it

[short charm]

Ok that's fair

But hard to justify if you already have an oag and a filter drawer

I personally can't wait til touptek makes the built-in guider color imx clone of the new ZWO camera

[patent dove]

would you still be able to use a dual band filter with that camera though?

[short charm]

Lol nope

But at f/2 idk if I want to use duoband filters, those are quite pricey

I guess an l-enhance would be fine, but that's about it

[patent dove]

eventually I'd like to get the IDAS NBZ for it

[chilly ingot]

@short charm found something to pair with the M48 bayonet replacement for filter usage

https://www.teleskop-express.de/shop/product_info.php/info/p10857_TS-Optics-M48-Filter-Holder-for-mounted-2--Filters---Length-15-mm.html

im tilt paranoid atm

[short charm]

Yeah without doing a lot of research won't be able to help you 😅

[hollow root]

Does anyone know how to do focus mod on 135mm rokinon lens?

[short charm]

As in attaching an EAF?

[hollow root]

No but like basically there’s a hard stop near infinity and you can get fully focus or something

There’s a video for focus modification but it was Timelapse and I don’t know what they did

I am a visual learner so hence why I am just trying to ask

[chilly ingot]

Nebula photos has a youtube video about that

[hollow root]

Yeah Ik but I can’t understand it

[hollow root]

Nebula photos is what I refer too

I kept rewatching him and yet can’t understand what to do

@chilly ingot

[chilly ingot]

Idk, i found it quite straight forward

[hollow root]

Do you mind helping me with it if not it’s fine

[chilly ingot]

well. you literally turn the lens to infinity stop

peel the rubber grip from the focus ring down to reveal the screws

remove the screws

then you can pull the focus ring down to reveal the infinity focus stopper plate

unscrew it and store it somewhere safe

assemble in reverse without putting the stopper back

[hollow root]

oh thats all i thought you adjust the infinity thing I guess not

then that should be easy then

[chilly ingot]

@tender apex noticed that the pdf you made. When i focus with the middle left spiky thing with the dot in the middle

When there is tilt. It has double circles in the spikes and purple CA

i have my tilt plate atm tightened flat with no adjustments and it went away. Also M48 bayonet replacent on the lens, filter cell

So atm with these only there is already less tilt

[worthy grove]

Sounds promising and that its not the lens itself!

[chilly ingot]

Testing today after work

Printing two A4’s with dots to ballpark it indoors

One with inverted colours

[short charm]

RIP your printer ink

[chilly ingot]

Printing at work ofc

[short charm]

RIP your departments printing budget for the month

[chilly ingot]

Dont care

Boss buy new cassette

[chilly ingot]

ok this was 1st test sub

wtf

seems like replacing the filter drawer and bayonet did alot

i did the method of debayering, converting grayscale and inverting the image

[tender apex]

yep, I made that thing packed with as many features as possible 😄 that test is how you test for decentered optical components and other flaws in mainly lens based systems, on my mirror based scopes it makes a nice focus test when taking an image, as you can very clearly tell if your at best focus or not

[chilly ingot]

well outside under the stars there was still tilt

i saw the most amazing meteor though

it was so near

could hear it soar and it had a nice tail and cool fireball at the front

[chilly ingot]

lens is garbage

[worthy grove]

Oh dear. You've narrowed it down to the lens? Are you able to send it back for a replacement?

[chilly ingot]

i made it stock now. ill bring it to the repair shop when im on my summer vacation

idk if i send it to sweden to the official samyang repair shop

a local shop here sayd they will take a look at it

its fine when imaging on daylight with big pixel dslr

so idk if lens service places care at all about astro photography

[twilit hound]

[chilly ingot]

imagine if i had Askar 135 that costs less

it would probably be perfect

[hollow root]

Hello guys I modify my focus for rokinon 135mm and now it doesn’t like to focus at all

[worthy grove]

What about the focus did you modify? Just removed the infinty stop?

Removing the infinty stop shouldn't affect its ability to focus at all just means you can go past its original stop

[hollow root]

Yeah I just did that

I went all the way to infinity and got this

[worthy grove]

well you've probably gone past infinity? roll it back

[hollow root]

Like modify it to not go past or just adjust the focus

[worthy grove]

just adjust focus

[hollow root]

Ok well I tried to adjust it near the infinity and it still does that

The only time it got sharper is when

I step up the aperature

[worthy grove]

Well you haven't done anything that should affect the focus so go through the whole range and you should find it. What camera are you using?

[hollow root]

Canon rebel t7

Is what I’m using

[hollow root]

So also what you mean it could be like the middle focus that can be sharp and not infinity?

[hollow root]

@worthy grove is that what you mean

[twilit hound]

💀

[hollow root]

But why would it do that bc before modifying it would be near infinity for mostly but not all focus

[chilly ingot]

been puzzled by this and i dont even know what is going on

you removed the stopper plate and its 3 screws, reassembled

and cranked it to max and it is not in focus in its new maximum position?

the point of critical focus shifts while the lens cools down

and with fast optics like this lens, the point is really really narrow where it is in focus

it is somewhere around the last 10 - 3mm of the end of the turn

depends on tempature

[hollow root]

Oh alright

But then why would it be much more in focus near the maximum infinity focus when I step up to like for example f/11 or f/22

[chilly ingot]

hard to explain but, stepping down the lens increases the depth of field and the point of critical focus is broader

but you let in less light. thus increasing the exposure time needed to get compareable results than lets say, f2.8

by quite a big factor

and when the lens is closed down alot, there might be weirness going on with diffraction

i really have no idea what is going when you only enabled more room to find the focus near infinity

[hollow root]

Oh alright

[fallow stirrup]

both captured with the rokinon, which is nicer

[worthy grove]

They look great! I prefer the second one.. What region is this? Im not familiar? The first is the triffid I guess?

[uneven compass]

Rho ophiuchi. First is lagoon/trifid

It looks like there's a weird cutout around Antares on the rho one for some reason

Both are good, I prefer the lagoon one however as the Snr is a good bit better. Definitely get more data on rho if you can

And are you dithering?

[fallow stirrup]

Lagoon did dither, rho didn’t dither

[uneven compass]

Makes sense, definitely keep doing that

[short charm]

@lone tendon decided to get the astrodymium AF kit, and yeah they definitely use that knob to stop it from rotating

That and the lip

[worthy grove]

More nice stuff from the Roki! Love this lens. Wondering when Ill buy a scope at this rate 🤔

[chilly ingot]

got some 77mm metal dewshield for the roki from aliexpress

it screws on the filter thread. seems ok

but i noticed my Z61 scope's cap fits it perfectly and the WO bathinov mask can be used with it

[solid raptor]

What would generally be the settings to get the best star colour?

[short charm]

That depends on several things, but ultimately don't max out the well depth for good star color. You also may have to shoot in 2 different exposures if your nebulosity is super faint or you have low well depth in your camera

[solid raptor]

Oh yeah in this case I actually just wanted to shoot stars to use them as starfield on other images but I also have to shoot some Rgb stars for my dnb images. I reckon about half an hour of integration time should be enough?

And finding out technical details for daytime cameras proves to be difficult sometimes, maybe I can find something in the sensor's spec sheet

[short charm]

Yeah for star data you don't need a lot, 30 mins is quite plenty at f2, just need to drown out the read noise

[short charm]

https://www.photonstophotos.net/Charts/Sensor_Characteristics.htm

Only site you ever need for that

For commercial cameras at least

For example

[solid raptor]

I'd rather step down a bit to get perfect stars? My copy isn't bad but it isn't that good xD

[solid raptor]

Oh thanks I looked but couldn't find it

[short charm]

I personally hate the roki diffraction spikes, so I use aperture rings instead

And with those I actually have really good stars at f2.3

[solid raptor]

Oh true I forgot about those, they do look quite spikey, I'll stick to 2.8 then, 2 is a bit unsatisfactory since I also have some tilt

[hazy copper]

New Roki image

[patent dove]

If you want you could shoot at f/2 for like 90% of your data and then f/2.8 for the rest and then only use the stars from the f/2.8 data

[solid raptor]

Won't the nebulous structures suffer from that nonetheless?

[patent dove]

I don't imagine it would affect the nebula that much, and since f/2 is twice as fast as f/2.8, f/2 should look better with twice the data in the same amount of time

At f/2, are your stars not round? Or is there just more chromatic aberration?

[solid raptor]

Tbh I never tried it at 2 because I assumed it could'nt be too fantastic but I did try it at 2,4 once and I was unsatisfied

But that could've been other factors as well, not quite sure

Should do a thorough test sometime

[patent dove]

Alright, yeah I'd experiment with it, make sure you get perfect focus too, stars will look bad if focus is even slightly off at low f ratios

[hazy copper]

Yeah chromatic aberration can look much worse if focus is slightly off too.

[solid raptor]

Hmm does a bahtinov mask not provide enough accuracy?

[gleaming flare]

next to autofocuser bahtinov mask is the best

[short charm]

Yes but focus does shift through the night, and an autofocuser not only keeps that in check, but also makes sure you're in a perfect spot. You can do the same with a baht mask, but it will be far more tedious

[solid raptor]

Oh tedious I can sing you a song about tediousness xD. Especially when I see that the temps will drop I refocus at least every 30 mins, also gotta polar align every now and then and I dither manually, which is especially unpleasant when it's cold outside

[short charm]

Sounds like you need a lot more toys then 😅

[solid raptor]

I mean when shooting narrowband focusing with the bahtinov mask is kind of tricky I find

[short charm]

I feel like NB you definitely need an autofocuser

[solid raptor]

More toys sound good 😄

I have a post somewhere in #1021002743080558642, could you have a look at the focus real quick?

My bad, it's in #1021002578588352572 @short charm

[short charm]

About to fall asleep here, so probably not right now 😅

[solid raptor]

No worries sleep well 😅

[worthy grove]

Another nice job from the Rokinon!
I've tweaked my process for imaging nebula now, I use the dual narrowband filter for the bulk of my imaging to get the nebula then use my basic uv/ir for some LRGB data and the stars, it seems to give much better stars for me, I then use the dual nb data for HOO and merge with the LRGB data

[summer apex]

Rokinon 135 + redcat ring + zwo aef + BlackCAT EAF adapter for redcat 51. Fits!

[chilly ingot]

I got blackcat mount too

For eaf

[summer apex]

Haven’t tried it out yet, but will once the summer nebulae are up!

[chilly ingot]

Trial run the settings

So you remember a step count what is a rough focus

Set eaf to reverse since its upside down. So it wont go over the infinity and jam against the stopper when doing the autofocus v-curve

[summer apex]

Got it to focus on some nice tree branches 1/2 mile away 😬

[chilly ingot]

Well maybe im an idiot about the upside down thing. But i had to use it on reverse setting

It racks the focuser alot of steps one way 1st

If its normal direction it will run out of travel in the focuser near infinity. With reverse it goes the other direction with plenty of room

[summer apex]

Ok! Will do reverse when I actually have it do a run!

[summer apex]

Yup, reverse is definitely the way to go!

!

[winter herald]

i’m getting a SWSA GTI with a roki 135mm attached to a nikon d3000. Swsa GTI has been ordered but will take 10-15 working days so if that’s true it won’t arrive for my birthday 😐 don’t even have enough for the lens yet but i can’t wait to get the whole set up done .

i’m coming from a celestron astromaster 70az so it’s a HUGE jump . can not wait

[worthy grove]

This little lens can grab the supernova from 22 million light years away!

[solid raptor]

Most impressive

[chilly ingot]

Did you dither the subs? If so, drizzle 2x to do a cheeky crop closer.

usually its good to deconvolute and resample back to original scale, but its kinda neat to get a closer look that way

[worthy grove]

I sure did, every 6 mins. Never tried drizzle, ill give it a go

[chilly ingot]

Probs works better with more dither. Gets better values for the new scale

[worthy grove]

My dithering is pretty extreme as I dont have a guidescope the dithering seems quite aggressive

[worthy grove]

Drizzled

I went a bit far with the decov but Ill play with it more. Nice idea @chilly ingot

[chilly ingot]

@worthy grove crop more!

earlyer. so you focus all most of the processing to the meat of the image

easyer to dbe and stuff

[worthy grove]

yeah, makes sense

[uneven compass]

Rokinon/Samyang 135mm discussion

I'm sorry the lack of a / was bothering me

[warm turret]

Hello friends, quick question. I have thoughts about buying the 135mm, the pictures are so amazing 🙂 but I only have the omegon lx3. Would you say that this easy tracking system can handle this? (weight would be all in all 1,56kg, so below the „allowed“ 3kg)

[worthy grove]

Well I use the SW az-gti and its fine (although the max load is 5kg thats in al-az mode and realistically in eq mode its probably more 3kg like you're omegon) so without knowing much about the omegon I would say it should be fine weight wise. what camera are you going to pair it with?

@chilly ingot Here we are with a closer crop with my 2x drizzle reprocessed as you suggested, what do you think?
I have to say for a 135 lens in B7 I do find it incredible we can almost match the res of some big newt rigs!

[chilly ingot]

What ress is that

[worthy grove]

erm 3753x3207

[chilly ingot]

How would it look like with a 2k ress

2560x1440

[worthy grove]

Here ya go

I probably should go easier with deconvolution though

[chilly ingot]

Maybe some masking trickery to control the noise

like so it wont get stretched too much and saturated

[worthy grove]

ill post the data in #1021002743080558642 so someone can have a crack

[worthy grove]

Here ya go https://discord.com/channels/794642864218439681/1111625696935153674

[warm turret]

Well, the SW is totaly fine there, but at the moment I would rather like to spend money for a new lense. I use a Sony Alpha 7s, really nice noice behaviour, but resolution sucks. I have conserns about the lx3, cause its "only" an mechanical tracker

More weight capacity probably means a more accurate tracking, question is only for me where's the border of the focal length

[worthy grove]

If you're using a Full frame sensor then I don't think tracking should cause any issues for your resolution at 135mm

[warm turret]

the 7s only got 12,1 MP

[hazy copper]

MP doesnt matter. In fact lower generally means nice big low noise pixels

[short charm]

Only thing to consider is sonys star eater effect with the bigger pixels and lower FLs, not sure how pronounced that may be here though

[patent dove]

Im getting a dual band filter for my roki, what do you guys think, IDAS NBZ or go all in with the ALP-T high speed? High speed is fine since the next scope I get will work with it still in the f/3-4 range

[chilly ingot]

something you can return if you get halo's

[patent dove]

yeah true

[chilly ingot]

The nbz uhs is like f1.4 and abit slower, normal nbz is f2 to 3.5/4 ish

L-extreme f2 edition is coming. Dunno about halo’s and returning

I did a 5min sub at horsehead with NBZ and no halo. Was with f/4.7 tho

[patent dove]

there’s also a new NBZ called NBZ ex that is advertised for f/1.8 to infinity

it’s 12nm bandpass though

[chilly ingot]

oh nice its like a l-enhance then

[patent dove]

it’d be nice if they had a high speed l-Ultimate

[worthy grove]

I got an l-extreme second hand off eBay and boy does it give me lots of halos to clone out 😂

So I echo the advice to get something you're able to return

[patent dove]

yeah halos are annoying, I'll make sure to get one I can return, good point

Do any of you use the ZWO EAF with your lens? Worth it?

[solid raptor]

Is printing a lens collar for this thing recommendable?

[chilly ingot]

Having a focuser on anything is nice.

[short charm]

I use a diy focuser with mine 😅

Definitely worth it!

[short charm]

I wouldn't print a collar, I'd print a ring system instead, cause plastic is more bendy than metal so you want more than 1 point of contact

[solid raptor]

Would an aluminum one work to balance it better at steeper angles?

[short charm]

It will probably just bend less under that weight

[solid raptor]

Ive seen one for 15 bucks that is reviewed well and weighs 120g

I want to put less stress on my ballhead

[short charm]

Gotcha, well that will work, I used a collar myself for a bit before switching to a system

Ultimately, I went away from ballheads with this though, I just find that this lens in particular is quite heavy

[solid raptor]

At lower angles it works ok but once you get above 45° things get funky

[solid raptor]

And you switched to what exactly?

[short charm]

https://astrodymium.com/products/astrodymium-rings-for-samyang-rokinon-135mm-f-2-lens

Allows guiding, mounting an autofocuser and is super sturdy

There's 3d printable versions as well

[solid raptor]

Is it mounted on an arca swiss plate?

[short charm]

You can mount it to one, just need a long one or the William optics switchable one

One thing to note is that you need a plate that doesn't have the grooves prefit for the standard screws, as these are m6 iirc

Or just mount a vixen to an arca swiss lol

[solid raptor]

https://www.bhphotovideo.com/c/product/1062507-REG/desmond_dpl_169_7_3_4_long_lens.html

Could I mount it on that?

[solid raptor]

So basically like that xD

[short charm]

https://astrodymium.com/products/dual-sided-vixen-arca-swiss-dovetail-bar-plate-for-astrodymium-ring-system

You can also just order this with it

https://agenaastro.com/william-optics-dual-sided-vixen-arca-swiss-110mm-4-3-dovetail-plate-space-gray-m-prc110tg.html
Or something like this

That way you're future proofed for a real mount

[solid raptor]

Why does everything get twice as expensive once william optics is printed on it

[short charm]

Brands

I was going for something like that, doesn't need to be WO lol

But WO is cheaper than other dual designs from primaluce or the likes 😅

[solid raptor]

IS the difference between the upper one the material?

[short charm]

The upper one is just 3d printed, and seems to be sold out atm

[solid raptor]

The idea is very compelling, thanks for the info

Do you know of anyone here that has printed one of those rings?

[short charm]

Well those astrodymium rings linked are paid only I'm afraid, but I think @hazy copper had some other printed rings that are available to download?

@solid raptor https://www.printables.com/en/model/153157-openastrotech-samyangrokinon-135mm-cradle-with-foc
found it

also has an arca swiss plate

honestly, may print that myself and sell my astrodimium kit

since this is designed for the OAT

[solid raptor]

Do you plan to build that?

[short charm]

Mayhaps

[tired cypress]

Pretty

[solid raptor]

[short charm]

Waiting on nema cable extenders cause the nema14 cables are a bit too short for the focuser

And the AUTOPA system is complete, so now I just need to find a box big enough to hold it and I have a portable self setup system

[solid raptor]

And the nema 14 can run that thing?

[short charm]

easily

problems start when youre me and trying to run it off a nema 8

[solid raptor]

xD

How long do you plan to be able to expose with it?

[short charm]

Oh you mean the OAT, that's running nema 17s everywhere lol. The focuser part is nema14

And I just dialed in decent settings for the speed of the nema8, and it's barely not able to turn in one of the directions, so hopefully a stronger nema 8 will do it, gotta grab it out of the car

[teal burrow]

Can anyone here give me some input into whether or not my Roki 135 is a bad copy?

Way back when I first bought it, it looked perfect, but now comparing my images to other Roki 135 images, the amount of coma and aberration on mine is horrid

I'll send a PixInsight Aberration Inspector mosaic, let me know what you guys think

Wait I just did an aberration inspection and the stars are perfectly fine I think I'm tripping wth 💀

I'll take a shot anyway. Full photo, and mosaic

[worthy grove]

Looks ok to me. You're out of focus though?

[teal burrow]

What makes you think that? The focus looks fine to me

Geniunely curious

[worthy grove]

The stars are blurred, unless the image you posted is really compressed?

[teal burrow]

Oh yeah no it's super compressed

I used a bahtinov mask, the focus was pretty dialed in

[worthy grove]

Ok fair enough. Hard to inspect the image of it's so compressed. The stars look ok to me though. The usual amount of chromatic aberration I would expect with that lens

Can you upload an unedited sub?

Did you do any star reduction? That can enhance any aberration

[teal burrow]

Yeah I did, BlurX. I'll send one of the 30s subs

[worthy grove]

I find blur X can enhance the chromatic aberration that already exists and you have to back off the star reduction

I'll look at your sub later when I get to my computer

Usually the complaint with rokinon bad copies is tilt and it doesn't look like you have that

[teal burrow]

That's interesting, I'm gonna keep that in mind. Plus I think I clipped a lot of stars here and bloated a few since I was shooting at F/2 ISO 800 in a Bortle 3

I think it'd probably also help a lot to just go with shorter subs especially with the f/2

[solid raptor]

Is anyone using the roki with a FF camera?

[worthy grove]

I used to with the canon 6d

[solid raptor]

Were you happy with the fov?

[worthy grove]

For things like Orion and the heart nebula yes, but it wasn't long before I moved to the Uranus-c

I wouldn't have been able to get this with my 6d but I got some great Orion widefield shots I was very happy with

[solid raptor]

What do you adapt it with?

[worthy grove]

https://www.firstlightoptics.com/zwo-accessories/zwo-adjustable-eos-lens-to-t2-adapter-for-all-asi-cameras.html this thing, works great

[worthy grove]

Looking at this properly i can see you are indeed in focus.. I shouldnt look on the phone, my bad.. .The sub looks fine too so i think your lens is fine, I think you may just have stacked some bad subs in your processed image as there are some funny shaped stars going on?

[brisk yoke]

I love Rokinon lens

[patent dove]

Anyone use the Astronomik L-3 UV/IR cut filter? I'm getting a 2" IR cut filter and have read that this filter helps CA a little even though mine isn't too bad

[short charm]

I'm using an l-2 clip in myself, which is a bit narrower iirc

Are you using any uv/ir cut filters rn?

Also you need a uv/or not just ir cut filter, the CA usually comes from high frequency blue light, not the red

[patent dove]

yeah I am, the ZWO one

and yeah you're right, its the blue haloing that can sometimes be a problem

L-3 is the narrowest of the three

The website says the L3 is designed for "refractors that have less than perfect color correction" and that it will "minimise the problem of bluish halos"

[tender bison]

I got one end of last week, but I don't really know what to make of it right now. I feel like there is a bit of everything, but not sure if I should stick with it and i'm overreacting or not..
These are shot with a modded DSLR without any fitting UV/IR Cut filter. I know this will/ is causing issues as well (halos), but then I'm worried about having the stars in the center somewhat focused while they look like a smudge in the bottom right corner
idk 😅

[patent dove]

Is your DSLR Ha modded or Full spectrum modded?

[tender bison]

That would have been great question ask when I got it second hand . Stumbled over the same issue/ question when researching a bit further - I don't think there is any way I can test this without needing to tear it apart?

But I would guess it is HA modded only, as I can still do a proper whitebalance of daytime taken photos in post processing - when looking at them in the camera itself they have a strong red hue with normal whitebalance if it helps

[patent dove]

Yeah I dont think youd be able to white balance with full spectrum so youre probably right

I think the chromatic aberration in the first pic is normal but the aberration inspector corners do look weird, mine dont look like that with an APS-C sensor

[chilly ingot]

looks similar to my copy

sensor and pixel size?

[winter herald]

hello i’m getting a roki 135 soon , what’s the difference between the two ? i have a nikon d3000 btw if that matters

it’s UMC and AE , both on amazon one out of stock one in stock

is it something to do with the focus and telephoto lens??

[winter herald]

i’m not great with cameras tho and what lens suit cameras so i’m sorry if i get the obvious wrong lol

[uneven compass]

They're identical

[short charm]

Yeah they are the same company, just in different regions they sell under different names (and sometimes both brands exist in same region)

So whichever one is cheaper and you can send back multiple times to if stars are bad

Just make sure it's not the cine version

Which will have that in the name and will have very spiky rings meant for video adapters

[uneven compass]

The cine version is also identical aside from the click less f stop ring

Admittedly that is annoying, but it's usually cheaper and that might be worth it to you

I've used it for a while now and it works great

[winter herald]

ahh okay so i can order either one and they will work the same ?? there’s nothing different in them just the case that one is in stock and one isn’t ?

[chilly ingot]

@tender bison this was not a compliment. Ur copy is made on a monday by a hung over worker

[tender bison]

Thank you for the feedback

[chilly ingot]

Few kinds of aberrations visible to weird directions

[twilit hound]

the cine version is for amateur cinematography or videography, de-clicked aperture rings are necessary for that. you wouldn't get the cine version for something like astrophotography

[uneven compass]

Agreed, but for example in my case the cine was significantly cheaper

Yeah it's a drawback, but I image at f2 anyways and when I do eventually start using f2.8 for narrowband, I'm just going to use stop down rings

[civic mirage]

less spikes too

[solid raptor]

@twilit hound There's a really nice roki for sale rn, might be interesting for you 🙂

[twilit hound]

don't got the money right now sorry, but thanks

I only have managed to get $186 since I purchased that lens, plus I would only buy one if image samples were included as well

and if I did buy another 135mm lens it would probably be a sigma 135mm f1.8

[chilly ingot]

lets start a canon 200 club

another russian roulette lens probably

[twilit hound]

I dont like that lens for its spikes + red stars

Needs stopped down as well

Im not really into astrophotography either anymore

[chilly ingot]

thats the nico copy that is worst ever recorded

[twilit hound]

not sure about that but I've seen it almost all over astrobin

[solid raptor]

Sell the old roki, plus samples are included and the seller is a very forthcoming person. But yeah your reasoning is understandable

[twilit hound]

I unfortunately cannot sell things

nor can I return things either

once I buy them Im stuck with them, forever

[chilly ingot]

what are you gonna do when you get out of jail?

[twilit hound]

lol what

[chilly ingot]

when you get to expirience real freedom ofc

[twilit hound]

Idk

It's not that easy

moving out doesnt allow freedom if anything it just confines it even more

[wild valve]

Just found out this chat exists, and was wondering, if any of you are looking for purchasing the lens? If so I just happen to be selling it, along with an autofocuser, adapter, rings, and guide scope handle…
For more info, send me a PM.

Pls let me know if such messages are not allowed in this thread, so I can remove it.

[twilit hound]

@chilly ingot my family is ok with me applying for getting a job next year. If that works out then I'll get back into this stuff

[chilly ingot]

[twilit hound]

That's excellent, although I do recommend #1023613540587810846 would perhaps be a better place for that

[chilly ingot]

ey its cool, send the sample images here btw. i think i saw ur advertisement and it looked ok

[wild valve]

I have done that, but just so more people would be informed about it. I want to upgrade ASAP to a bigger scope😂

[chilly ingot]

checked again. think you should click down abit

[wild valve]

Meaning.?

[chilly ingot]

or is that backfocus actually

[wild valve]

Mono image was backfocus

Color image is f/2

And APSC sensor

[wild valve]

That’s also tilt… unfortunately

[twilit hound]

yeah that looks like tilt

certainly a lot better than my copy

[chilly ingot]

from a stack

at like f3.2 or slower

[wild valve]

My f/3.2 looks quite good ngl

[chilly ingot]

same "tilt" with my dslr's and astrocams

so its inside the lens

tryed with M48 thread adapter, filter cell instead of drawer

etc etc

[wild valve]

And now with modern software like BlurX that’s not a problem at all

[chilly ingot]

looks great

[wild valve]

And in center it’s really sharp

[tender bison]

I decided to just send it, this is 440x10 sec exposures of the cygnus region
But hey, I can identify crescent and the tulip nebula

[chilly ingot]

Did you check focus during imaging?

These fast lenses drift pretty quick when the temp changes

[tender bison]

yes, but not hard enough it seems
I ordered a bahtinov mask, will try again then

[tender bison]

that I cant really solve I think 😅

[chilly ingot]

You sayd you got this lens end of last week?

[tender bison]

yes

[chilly ingot]

Im sorry man, i would return that particular sample

[tender bison]

I checked, I still have about two weeks left until I need / should return it - I want to give it another try with the bahtinov mask which should arrive end of this week
I also read to try not to focus on a star in the center but on the outer third, then the average is better, so I will try that too

[chilly ingot]

are you shooting at f2 or clicking it down abit?

[tender bison]

I think it was at bit further than f2.8

[chilly ingot]

Alright. Pack it up

[tender bison]

very likely
I truly appreciate the second opinion

[chilly ingot]

Mine is similar. It is literally a paperweight

i cant return it because i was clouded out for a month or two after getting it

Return period is 14days

for me

Bringing it to the service shop when im off work for two weeks soon

Praying something is just assembled wrong

[tender bison]

I have to say, whatever ppl thought about the thread of @twilit hound about this lens, I truly appreciated just the information that these issues might popup, so I looked out specificially for the weather the next days for when it arrives before I ordered it

[chilly ingot]

A great roki will get good stars at like f2.8

If its super sharp at f2. Keep it for the rest of ur life. If someone wants it for astro. Ask 3times the price 😂

[tender bison]

I sense a great opportunity of investement deals selling quality-controlled rokinons and returning the bad ones

[chilly ingot]

I dont mind a mild blue CA

but if the stars look like comets and helicopters….

in a traffic jam

[tender bison]

@wild valve taking notes 😂

[wild valve]

What notes?

[tender bison]

because yours doesn't seem to have these issues and looks tempting now

[wild valve]

Oh no no… I’ll sell it for less then it is new.
I don’t want to rob anyone, and I want to get as much money from my used gear, as the new scope combo will cost.

[chilly ingot]

its pretty bad.

[tender bison]

Jasa`s? Actually I meant his offerring referring to your joke
I think it looks much better, especially looking at the f/2 open picture with the nikon

[chilly ingot]

no, my roki

[solid raptor]

Does anyone have broadband target suggestions? (49°N)

[short charm]

Those with less Ha? theres quite a few dark nebulae in the north that are rising like the shark head nebula and that region in general. They are dim and need dark skies, but possible for unmodded cameras. You can shoot Rho Ophiuchi, it will be quite low for you but doable and bright

[solid raptor]

Oh yeah I'll definitely try Rho Ophiuchi if I'll have good vision on it and since I saw a nice possible dark-ish location maybe reflection (and perhaps dark?) nebulae might also be possible

Getting the integration time will be difficult with nights not longer than 2,5h 😬

[short charm]

Yeah there's a lot more NB targets right now, but you can definitely still get at some of them though!

[uneven compass]

At 49 north you're gonna have some trouble with rho lmao... honestly your best bet is dust in cepheus. Not a super optimal position right now, but it should work. It's all pretty dim, so you're gonna want to sink time into it if you can

Even though there's a lot of ha, cygnus really isn't bad in bb either. Especially if you have a modded cam that'd look pretty great

[short charm]

I'm at 39, rho is low but not undoable, guess 49 is much worse though if I think about it more

But not many bright broadband only targets rn

[solid raptor]

Yeah it'll only rise up to 15° that's not much but I don't think I'll need thaat much data on it

I guess I'll stick to narrowband, though it is quite frustrating on a stock xD

[short charm]

Time to mod lol. Or get a modded camera, you can find them cheapish at times. You can also look for ghost cameras cause those "hunters" do the same mods as we do but it may be cheaper

[gleaming flare]

That's actually a good idea, the ghost modded cameras are cheaper than astro modded

[chilly ingot]

no astro tax?

[solid raptor]

No way xD

I want to mod but not my a6000

That's why I wanna sell it and get sony full frame to mod

A7ii or a7iii

Hmm there's a modded a7ii for 450€ on ebay, doesn't sound too bad...

[hazy copper]

At that price get a used 533

[solid raptor]

Cheapest one I see is 588,plus I'd probably have to get quite a few accessories

But the thought is tempting

[winter herald]

it finally came , this will make my nikon d3000 useful💀

[twilit hound]

nice, let me know how the stars are

[winter herald]

thankyou , i will do , i’ll send them here 🙂 goona try a shirt untracked exposure tonight to see if they’re good enough , if not i’ll send it back and get the lens by the time my SWSA GTI arrives

[winter herald]

i’m testing the lens out and it keeps saying this , to lock the f ratio do i turn it to the right till i can’t anymore then i click this to lock it in ?

[chilly ingot]

The lens is completely manual with no electronics. There must be some camera settings to tinker so you dont get that message

Might be some dumn white balance thing or something

[winter herald]

ahh okay , i’ll try it out again later

every time my camera turns off it pops back up

[winter herald]

we have a problem my focuser doesn’t turn to the infinity sign , great

[chilly ingot]

Yeap. Common thing to do is to remove to stopper to access the extra 5mm of focuser throw. Usually helps when then lens contracts in the cold

Usually these kinds of things voids warranty. Perfectly good optical quality roki’s need this too

Its a shame

[patent dove]

how many hours do you think id need to bring out the Ha clouds around andromeda with a dualband filter? lol

[chilly ingot]

oh you mean the newly discovered big faint areas?

isnt that with some special oxygen filers and not ha?

[patent dove]

nah the Ha, the new Oiii structure is insanely faint

this stuff

[chilly ingot]

just leaving this here

https://cdn.discordapp.com/attachments/1062506596904743012/1118249026295443636/image0.jpg

[solid raptor]

insert Caphe xD

[gleaming flare]

[uneven compass]

This image was actually taken by a friend of mine

Let me look at the exposure he used

10 hours, 7 from b9 and 3 from b4

[patent dove]

at f/5 cause he used the Meade Quad right?

[uneven compass]

That was with a roki lmao

F2.8 I'm guessing, that's usually what he uses with the l extreme

And 533mc

[patent dove]

Damn nice, thats my setup too except I dont have the filter yet, Im planning to get the highspeed ALP-T

I know he uses the meade quad so I assumed it was that

[uneven compass]

That's sketch

I don't think he has a mead quad lol

Jimmy (another person who has done a really nice m31 ha image) does, maybe you're getting it mixed up with him?

[patent dove]

im thinking of jimmy yeah, idk how I got that picture and thought it was him then

[uneven compass]

Jimmy's definitely had a lot more detail, but his gear was also way more advanced

Its... doable with a swsa. Just not super fun

[patent dove]

this is jimmys yeah

I know the details of the image were posted on reddit but the reddit is privated right now

[uneven compass]

Yeah lol

I think it was ~30h though

If you want good m31 clouds you need to sink data

[patent dove]

yeah itll take a while to get a good result

although your friends image is really good

10 hours isnt too bad

[uneven compass]

Yeah for 10h it's pretty great

He's ridiculous in pix though

[patent dove]

and in a city

[uneven compass]

Honestly, I'm not sure I'd bother unless you could get a solid 20 though

[patent dove]

im willing to do 20

I think I'll try f/2.2

and itll all be from bortle ~4.5 where I am

[uneven compass]

You should definitely be able to pull something out then

At least with proper processing

What's the bandpass on the filter you're getting for ha?

[gleaming flare]

this is one of the most beautiful andromedas ive seen

such good HA

really makes it pop

[uneven compass]

Jimmy is amazing lmao

[gleaming flare]

beautiful processing too

[patent dove]

Since im using a dualband filter I wonder how much of the inner oxygen structure(not the arc) I can get

[uneven compass]

Duoband isn't exactly optimal for oiii

Tends to have a pretty wide bandpass

[patent dove]

yeah true, alp-t seems to be one of the better ones in that regard at least

[uneven compass]

You'd just need to see though, oiii m31 is quite new

Oh wait that one is 5nm

That's actually quite good lmao

[patent dove]

and expensive as hell lol

[twilit hound]

what

[solid raptor]

Because of this statement gping against your experiences

[twilit hound]

oh

[winter herald]

here were the stars , defo out of focus

goofy copy

[chilly ingot]

Also too long exposures

Can get away with untracked if you take a pic at polaris i think

Zoom live view to 10x and look at the bright star get smaller as you turn the focuser. If it clunks to stopper before it went a larger again from smallest size the stopper needs to be removed

[winter herald]

ill try a shorter one tonight

[winter herald]

has anyone ever done the fix themselves ?

like take the stopper out and then fix the focus

[patent dove]

the infinity stop? I have, it’s easy

https://youtu.be/Yk2myVjAFlU

[winter herald]

ah yeah i didn’t wanna take it apart i was too scared , but i got recommended a scope double for focal length for £130 more so i went for the scope , zenithstar 61