Ritchey–Chrétien enjoyers thread

[harsh matrix]

i was outside screwing with the OAG a lot

just before i started imaging tonight

but i didnt touch the imaging camera and i didnt put any torque in either direction on the imaging train either

i need a new guide cam for this rig

the 120MM is too bad to use even on the quttro for galaxy season on an OAG

i put my 585 on the OAG

[slate falcon]

get a 585tbh

dam, u said before it sent

[harsh matrix]

it's possible the weight of it made something shift but im not sure how likely that is

[slate falcon]

not very likely

unlikely*

[tight lodge]

P1 FHD-OAG MAX. The prism is designed to illuminate a 585🫠

[tidal hearth]

Was about to say i had that on my quattro 150p when i had the wrong backfocus

Ooo the quattro 150p reducer, that one is amazing

I would get the quattro 200 or 250 with the 150p 0.85 reducer 😉 get a bu spider and mask, add a cover on the back and a fan for air in the scope, and at last a new focuser

Also here u can get the reducer for the 150p

https://lacerta-optics.com/Komakorr1506_SkyWatcher-Komakorrektor-086x#nav-empfohlenes

[tidal hearth]

Or get a nexus 0.75

[tight lodge]

I don't think Vel agrees with that statement

[tidal hearth]

For that price? It def is

[tight lodge]

Funky annoying stuff happens when you reduce a telescope.

[runic violet]

It can only be considered good for small sensors

Sharpstar mpcc corrects much further and the Nexus corrects apsc

[tight lodge]

That's not the big issue. the issue is how far into the tube it protrudes. It's a long CC, and having it protruding inside the tube without any shielding or baffles, it's a recipe for disaster

[tidal hearth]

Like this ?

[runic violet]

Many of them intrude and it's not always a problem

[tight lodge]

it's better when it doesn't 😅

[harsh matrix]

The issue with them protruding into the tube is the fact that they can pick up light directly from the sky and funnel it down onto your sensor.

It floods the sensor with unwanted signal and tons of reflections.

[runic violet]

That's easily fixed one way or another

Move the mirror or screw a m48 spacer on the end of the CC

[harsh matrix]

i did both

neither worked

@slate falcon there's nothing immediately apparent with the imaging train

i dont see any new gaps or anything

[slate falcon]

huuuhh

did your focus slip?

not focus

collimation

[runic violet]

Then there's another source

[harsh matrix]

No

It's uneven throughout the whole focus travel.

[harsh matrix]

When I replaced the stock coma corrector, all of those problems went away.

I think the blame lies solely on how far into the tube that one needs to be.

[harsh matrix]

Hmmm I just noticed a larger than usual gap at the bottom of my OAG

[slate falcon]

oof

[runic violet]

Yeah it would be an internal reflection from the ordinary light path and not from being exposed

If you sufficiently protected the end of the CC

As in the stock cc was not painted sufficiently and that's the actual problem

[harsh matrix]

The front end of it was painted.

[runic violet]

The rest of it

[harsh matrix]

Unfortunately it didnt matter since the ambient light from the sky could enter from on axis light

[harsh matrix]

It would have required painting the inside.

And I cant be asked to take it apart and risk destroying it.

[runic violet]

You shouldn't have to do that lol

[harsh matrix]

I would have because the reflections were internal reflections caused by light from the sky entering from the normal aperture of the telescope.

I tested this too btw.

[runic violet]

My main point here is I don't think the problem is intrusion but the stock cc being badly flocked

If you sufficiently covered the end of the cc

[harsh matrix]

I know somebody who tried this and it didnt work.

I didnt give this a try because I already painted the front of it.

So the threads are all gummed up by paint.

[runic violet]

If you cover the cc with a spacer you are eliminating the possibility of light from the aperture entering the CC

The only source of reflection is from the secondary then

[slate falcon]

depending on the orientation of the cam that could be the problem

[harsh matrix]

There's an issue with doing this in my case too

The point of focus on the quattro 150p is such that you barely have to rack it out to reach focus with that CC.

That means that sometimes, you get misshapen stars and an extra pair of diffraction spikes because the coma corrector is so far in.

If I add an extension at the front longer than like 5 mm, it's over.

It needs to be longer than that to have sufficient area to dampen any reflections with flocking.

[runic violet]

Then sure that's the problem

[harsh matrix]

Even then

That particular corrector has something up with it.

The elements are introducing astigmatism or something.

It also cannot correct my 533 well.

Let alone a 571.

It's not sufficient for the kinds of things I want to do with this scope so a quality upgrade was already welcome.

[slate falcon]

can you even cut the corrector?

[harsh matrix]

No 😭

[slate falcon]

why nottt

is the lenses right at the end?

[harsh matrix]

Theyre about 3 mm from the front.

And I dont own an angle grinder

[slate falcon]

;-;

[harsh matrix]

It wouldnt be worth it across the board.

[slate falcon]

thats kinda shit

[harsh matrix]

Thats why it vacuums up every photon of sky glow.

[runic violet]

Yeah it can only work on very small sensors

I am only taking issue with the idea that protrusion is a problem in of itself

Because most ccs are very long and often protrude

[slate falcon]

use mini sheets of film

[slate falcon]

@harsh matrix i was somehow getting round stars while being the worst out of collimation i have ever been

how come i was only seeing half my mirror

but round stars?!

astrobrokenography

[harsh matrix]

💀

Horrendous seeing is about the only thing I can think of.

[slate falcon]

i thought i had horrendous seeing

this all makes sense now

on why i usually get 2-3 arcsec seeing

but recently its been so bad

soo

that could explain it

but it doesnt explain why the stars were looking good out of focus

[harsh matrix]

No it doesnt, good point.

[slate falcon]

buut now my stars do look a bit better

unexplainable phenomena

ig

the out of focus stars through the clouds is on par with my previous in focus stars

i mayy be cooked

[slate falcon]

previously it was measuring between 6-8fwhm

[vapid patio]

dang

[harsh matrix]

Imma run to the bortle 3 with my quattro

[vapid patio]

you could do marakins chain

however you spell it

[slate falcon]

i didnt realise that one nebula is so bright

monkey head

sadly wind is still real

[harsh matrix]

Nah ive already got a target in mind

Plus I did that last year

[slate falcon]

this is the best focus i have had in monts

wadafsk

now my hfr is like 3.2 -3.3

im slightly oversampled so it makes sense

[desert locust]

abell 13

[slate falcon]

no

sorry

not right now

i dont know if i will be able to

[desert locust]

why

[slate falcon]

caught up in some stuff

[desert locust]

ok

[slate falcon]

@harsh matrix 10 mins of data

stars look better than before

some dodgy frames are getting stacked here tho

heres after removing some more dodgy

[slate falcon]

omfg

its tilt

my focuser saggedf

could also be wind

this is a single sub

[tulip iris]

Is anybody expert here enough to tell me if by any chance i need to collimate the rc?

[harsh matrix]

Thats too far out of focus to be useful.

[sterile pendant]

Try this @tulip iris

https://github.com/insertnamehere1/Bahtinov-Collimator

It is impossible to tell if it is collimated with a picture of a screen. You are not coplanar to it

[sterile pendant]

There is mod to collimate with the defocus method

If you want a real collation, you have to use a tri-bathinov mask

I like these website to create one :
https://skeye.rocks/tools/mask/

https://satakagi.github.io/tribahtinovWebApps/Bahtinov.html

The tri-bathinov V2 is really good for collimation because it show the offsets better

[tulip iris]

Sorry i never did this beforr

I remember that to check the collimation i had to defocus on a star

[pine path]

There was a fun paper out today about getting an RC working https://arxiv.org/pdf/2602.16415

[silver ibex]

Officina Stellare 🤤

[sterile pendant]

It look very intersting !
Thank you for sharing

[frosty shard]

Actually posted something on Astrobin for once:
https://app.astrobin.com/i/0n10om

[slate falcon]

woa :3

[tall summit]

25inches of snow today

[slate falcon]

i levt you a comment

[slate falcon]

astrobin can translate cat!!

[oblique sun]

blue orionm

[desert locust]

I got like 16 lol

[slate falcon]

i got 0 inches

[desert locust]

u dont get snow prob

[slate falcon]

i do rarely

[digital nexus]

@harsh matrix What’s the largest sensor the RC reducer can use

[harsh matrix]

A 533 if that's the one im thinking of, you need a flattener to go any bigger. Especially with an RC6

[digital nexus]

I got the apertura 0.67x

So you put a flattener with the reducer? Huh how’s that work

Why did the reducer say APSC on Agena then

[slate falcon]

apsc for 8"

[digital nexus]

Sooo I just need to buy an RC8, got it

[slate falcon]

if ur fine wuth dodgy corner stars

[digital nexus]

BlurX fixable?

[slate falcon]

yea

its f8 so do you reeely need a reducer

[digital nexus]

F/9

[harsh matrix]

You could get a reducer/flattener. Something that does both, or get a flattener and put it behind the reducer. Flatteners are the only things with strict back focus requirements.

[harsh matrix]

I wouldn't even use that reducer with APS-C with my 8

The corners are already very dodgy at native with APS-C and the reducer will magnify that.

[harsh matrix]

Nice

[harsh matrix]

https://cdn.discordapp.com/attachments/1070137177410912329/1475631019163127981/20260223_000727.jpg?ex=699e2ffa&is=699cde7a&hm=15070c1a6a711480597a3a0e3cc600dff86c728536c450cb2a704f569aec1d0a&

We doin M 51 with the Quattro from here.

Im able to do 5 minute broadband subs all night without blowing anything out.

https://cdn.discordapp.com/attachments/975845011260309587/1475434456557944832/20260223_040102.jpg?ex=699e21aa&is=699cd02a&hm=a9ef244c306de91eca1e460753ec0c837a811eefe7c31d092199d87af9e5aaae&

Because the SQM went back up.

It seems to fluctuate heavily on a seasonal basis.

It's basically a bortle 4.5 in the fall, and then drops back down to bortle 3 in thw winter.

Perfect timing though because I want those super faint tidal tail features and I'm willing to run up here again for another 2 nights next month if it means I can make that happen.

[slate falcon]

smol stars

[harsh matrix]

Yeah the seeing was surprisingly decent for this location.

The aberrations present are from my phone and not the scope.

I did have to adjust collimation once I got here but it was an extremely small adjustment.

The field looks great.

[slate falcon]

thought so

[slate falcon]

yea!

[tulip iris]

Hah we always do the same things man

I did this some days ago

How much signal will u get?

[harsh matrix]

Uh I dunno

Was supposed to get 2 nights, >12 hours on it, but it's completely overcast despite every weather app I have showing clear and no clouds until 6 am.

So most likely, only going home with 6 hours of good data this time.

[tulip iris]

Ywah i feel you

Same

Yesterday i had technicslly i clear night

Came back home after going out and low clouds came in

I got 4 hrs on mine and thats it, dont look at the stars i have to reprocess it hehe

[stiff mason]

We usually do but this year we got non

[harsh matrix]

I was seeing about that much in single subs

https://cdn.discordapp.com/attachments/1325030460409249867/1475883625286340699/image.png?ex=699f1b3c&is=699dc9bc&hm=04773d83adcd397ced87cad1e627e1afbace1fc7523940c187ddcbb7b0568da1&

F/4.1 in bortle 3 with long subs is absolutely unhinged.

The brightest parts of both galaxies barely exceeded 50% of my camera's full well when doing 5 minute lum subs.

If i tried 5 minute lum subs from home, the whole galaxy would be white.

Or the whole image would be.

[harsh matrix]

@slate falcon you are right, the weirdness with the RC was a light leak

My tired dumb bass forgot to cover the primary collimation holes on my decoupler.

[slate falcon]

flo sells decouplers now

[harsh matrix]

Hell yeah

Thats the one I forgot to cover btw

might be the most insane data I've ever captured

[slate falcon]

[desert locust]

holy data

[desert locust]

rc 8?

[harsh matrix]

Quattro 150P

in bortle 3

w/ Televue Paracorr Type 2

I have been preparing it for this moment.

It has finally met expectations

actually exceeded them lol.

[desert locust]

i thought you had an rc

[harsh matrix]

@tight lodge

[desert locust]

https://tenor.com/view/black-man-crying-cry-crying-crying-emoji-crying-meme-gif-3223392509479903783

[harsh matrix]

the Quattro has grown up so fast

[harsh matrix]

I have an RC8, a Quattro 150P, and a RedCat 51

The Quattro 150P is my second rig for this season

[desert locust]

i will never gett a quattro

[harsh matrix]

I would have brought the RC but I didn't have time to pack it

I had to get there before sundown and was already leaving too late

[desert locust]

gonna image tonight, hoping for good data

6" f/5, gso better do me right tonight

[harsh matrix]

those 6" GSO mirrors are

[desert locust]

also first night guiding

[desert locust]

I thought that was just for rc's

[quartz meadow]

good luck sir

[desert locust]

what

[quartz meadow]

that everything goes well?

[desert locust]

oh, yea

i have no idea how to use open phd2 so im gonna need someone to help me tonight

[harsh matrix]

mainly for the newts lol

not really for the RC's

[desert locust]

do I use st4 port or usb 3 port for guiding

[harsh matrix]

usb

all the way

never use ST4

[desert locust]

good to know

[harsh matrix]

St4 is really good if you want spontaneous, unexplainable guiding behavior

[desert locust]

lol

[desert locust]

Setup pic

nikkor 300mm lens for guiding

[quartz meadow]

cute in proportion to the scope

[tall summit]

Made a path today so I can EVENTUALLY get out and shoot something:)

[tight lodge]

Oooh, that's juicy 🤤

[desert locust]

lol i had to do same

[slate falcon]

just did an 8 min long sub

with my wobbly mount

@harsh matrix@frosty shard is this sub good for being 1kg overweighed on a mount made for visual

[slate falcon]

@sinful sapphire

only slight trailing

[stiff mason]

Damn

[vapid patio]

my goat target

looking sick

[tulip iris]

Maybe my processing skills are just ass

[harsh matrix]

@frosty shard @slate falcon continuum subtracted NIR from lum here

NIR highlights the spiral arms

[slate falcon]

oh wow

[harsh matrix]

which is why there's a loss of contrast when adding NIR to lum

really cool to see

[slate falcon]

i think thats bc the spiral arms are more light bc of the light passing through it

[harsh matrix]

no

likely not

most likely you're seeing them glow in the near infrared because they are hot

just like the tail being thrown off by the companion

[slate falcon]

i forgot about the silly secret ir emissions from a radiation source

[harsh matrix]

yeah

[slate falcon]

i cant remember the name

[harsh matrix]

this reminds me of a JWST image lol

black body radiation?

[slate falcon]

idkkk

maybe

[slate falcon]

string cheese

[harsh matrix]

[slate falcon]

i need to get lum for this guy next year

and i will have to retake with longer subs

[slate falcon]

it looks like the inverse of when i use the elliptical star glow removal thingy i made and it just leaves the arms

[harsh matrix]

ye

[slate falcon]

ill have mono hopefully by then too

[harsh matrix]

@slate falcon well i tried to correct the affected flats with new ones that arent affected by the leak

there's some obvious issues here that we saw in the lights

this explains that

dunno where this dust mote came from either

i havent disassembled this thing since before that day and today

another way to look at it

i subtracted the old flats from the new ones tonight and these are the residuals

definitely a fat light leak

[harsh matrix]

2 nights in bortle 3 with an f/4.1 scope is goated

[versed roost]

thats insane... make it 5

[frosty shard]

THAT'S A LOT OF DAMAGE GALAXY CLUSTERS

[harsh matrix]

yup

[harsh matrix]

i might depending on weather

[frosty shard]

The BCG of the cluster next to the bright star is SDSS J133218.27+470937.7

I don't know if the cluster itself is catalogued

[harsh matrix]

it is called Zwicky 6057

[frosty shard]

Wait wrong cluster, that's the other nearby cluster's BCG: this one is SDSS J133218.27+470937.7

[frosty shard]

Oh thanks

Part of me is tempted to image just the cluster

[tight lodge]

Quattro finally performing?

[harsh matrix]

Not just

Literally obliterating my very low expectations.

[tight lodge]

This star alone is hubble quality 🤤

[tight lodge]

Wait... f/4.1?

[harsh matrix]

Yeah

It's F/4 normally and the paracorr has a 1.1x magnification factor.

[tight lodge]

Aaah, I see. That's why your focal length is almost the same as mine

[harsh matrix]

Yes

[harsh matrix]

Almost

The only things that bother me are my fault though

[tight lodge]

What did you do?😂

[harsh matrix]

Not sure atm

Whatever I did caused the bright part of the halo just around the core of all of the stars to remain extremely noisy despite denoising.

The RC seems like it very well may be completely fixed now as well.

The weirdness i saw in my M101 test WAS a light leak because of ME.

I created it out of negligence

[quartz meadow]

speaking of galaxy clusters, Is anyone planning on imaging NGC 4535?

[tight lodge]

Can't be worse than what I did to your M33

[tight lodge]

I won't. I'm planning to shoot the Coma cluster

[quartz meadow]

good choice

[tight lodge]

Nice framing too

[quartz meadow]

[tight lodge]

Yeah, I'm gonna try it so maybe I get my galaxy enthusiasm back

[bleak solar]

I have heared a lot of talk about electric auto focuses on a RC6 so I wanna know your opinion.
Yes or no? And why?

[tight lodge]

EAF are always good. No matter the OTA

[stiff mason]

Ehhh idk about that

[quartz meadow]

some stars from hubble look weird lol

[frosty shard]

Do you have a mono cam? If so, you may need one to preserve your sanity

You can get away without one as I did if your filters are sufficiently parfocal, but if not, it'll make refocusing for filters a whole lot more convenient

[bleak solar]

yes I do, I also have an EAF mounted on my RC6 but I was just curious

[frosty shard]

What I can say is that an EAF is not necessarily faster than manual focusing

[stiff mason]

Hubbles stars have much tighter cores yk being in space and all

[tight lodge]

He means that the star shapes look weird

[quartz meadow]

but the filters used made them look unique and not quite perfect imo

^good example pickles

[stiff mason]

Ik what he meant I'm just clarifying what i meant by my statement of "it doesn't look like hubble"

[quartz meadow]

I never said it looks like hubble tho think that was Pickles

[tall summit]

Just under 2h of break last night, including setup, before clouds and snow hit again:(((

[quartz meadow]

I can see some Ha, nice

[tall summit]

I swear, feels like this object is cursed for me:) I have lost 2 nights worth of footage to a corrupted files and a bad power cable, there hasn't been clear night in what feels like forever

[oblique charm]

its nice having a clear night after weeks of clouds

[tidal hearth]

Why have you lost it

[tight lodge]

M31 is to blame

[tidal hearth]

Don’t just do m31…

Or m101

Go with Ngc7320

[harsh matrix]

get it back

NOW

thios might be too bright

i think i may change it

I revised my M 33 image, adding more Oiii and improving the blending of the broadband + narrowband

oh and I changed the contrast between the brighter regions of the arms and the dimmer ones to make the transition smoother

[tidal hearth]

at the bottom left, is that a galaxy cluster?

[harsh matrix]

previous process vs new

[harsh matrix]

yes

Zwicky 6057

2.3 billion light years away

[tidal hearth]

@harsh matrix Your working with the advanced seq right?

[harsh matrix]

yes

[tidal hearth]

How can I restart my sequence so it doesn’t say 16/16 pics taken for example

Bc the progress is at max

I want it to be 0 again

Nvm I found out how

By hitting the reload circle

[harsh matrix]

[quartz meadow]

that galaxy field around M51 is really neat

[slate falcon]

colourful spikeys :3

[slate falcon]

is this w the 150quatro

[harsh matrix]

yes

[harsh matrix]

theyre thicc

[tidal hearth]

BTW how to I guide something when it’s moving from north east to north west?

Well: North -> North east -> North -> North West

[harsh matrix]

like what

[slate falcon]

150p has thicc spikeys with a cnc

[tidal hearth]

M81/82

[digital nexus]

Has anyone tried the RC reducer on a refractor

I want to try it on my Askar 71f

[harsh matrix]

you just guide

calibrate at the celestial equator

PHD2 handles the rest

[harsh matrix]

i dont own a refractor that you can put a reducer on

[digital nexus]

there’s such a thing?

or do you mean you don’t own a refractor

[harsh matrix]

petzval refractors

[digital nexus]

You can put a reducer on a Petzval

Askar sells ones for the 60f and 71f

[harsh matrix]

not on a redcat

[digital nexus]

well that’s a skill issue on William Optics ig

Dog for scale

[slate falcon]

[crisp flower]

Goddamnit i Just wanted to Take a Test frame for fun..
New Project it is lol

[harsh matrix]

Lol

Real

[crisp flower]

Didnt expect this in 60 secs xd

[harsh matrix]

I wouldnt have expected that either tbf.

[slate falcon]

i have that out of focus!!!!

[crisp flower]

It a beauty

[slate falcon]

it is even out of focus lol

[crisp flower]

Yeaa

[slate falcon]

veery defined structure

[slate falcon]

urs looks so detail

[crisp flower]

The 5min sub Looks Juicy as well

[slate falcon]

so flavour

[frosty shard]

Hubble is also oversampled

[stiff mason]

So is every telescope on earth

Except refractors

[frosty shard]

oops *undersampled

Sorry

[stiff mason]

But those arent telescopes

[stiff mason]

Oh

[frosty shard]

Plenty of fast Newtonians are undersampled too (with common cameras)

Though Hubble is f/24

[stiff mason]

Eh once you get to a large enough aperture you will be undersampled releative to your diffraction limit but never against the atmosphere

Unless you live on a mountain in chile or sum

[stiff mason]

How big are those pixels holy

[frosty shard]

In technical terms, they are big chungi

Idk offhand

[frosty flicker]

its got a fat mirror tho and is hypersharp

[frosty shard]

15 μm linear

[stiff mason]

The "high resolution" channel has 21um pixels 😭

[frosty shard]

on WFC3

[stiff mason]

Sill massive

[frosty shard]

It's all about étendue

[slate falcon]

even with a 6" its hard to be oversamples

im undersampled

[frosty flicker]

get better

[stiff mason]

I said large

Not small

[slate falcon]

yes

but its still hard to be oversampled with a 6"

unless you barlow up

or get 2um pixels or something

f4 2um ur still undersampled

what

the

[slate falcon]

im worng

ur just oversampled

[stiff mason]

I mean i am considering i got 1 arcsecond per pixel and my seeing is usually 2 arcsecond 😭 but sometimes we do get good seeing like around 1 arcsecond and those are the times i wish i had 0.5 arcsecond pixels

[slate falcon]

i wonder if an adc could help with good seeing even with long subs

[stiff mason]

Adc?

[frosty flicker]

Atmospheric Distortion Corrector

[slate falcon]

atmospheric dispersion xorrectir

[stiff mason]

Right well adc fixes the color separation so i dont think it will improve your seeing

Also if you got a mono camera you dont need an ADC

[slate falcon]

it shouldnt no

[stiff mason]

Wait did i misunderstood this wdym by that

[slate falcon]

lets say its good seeing but its a hot and humid day

like u wont be able to tell its good seeing

but it is

surely it would help

especially for lum data

[frosty flicker]

this calls for a science experiment tea

[stiff mason]

Yeah could help with a luminance data

[stiff mason]

Also how wouldn't you be able to tell like what is preventing you from being able to notice that it's good seeing

[slate falcon]

water in air

makes light not light properly

makes stars bloated

you wont get proper seeing readings

sleeby thoughts fr

[stiff mason]

I dont think adc fixes that

[frosty flicker]

if you tune the ADC properly you can

[slate falcon]

adc is insane for planety so why not deep sky?!?!

[stiff mason]

Yeah i dont see why not

[frosty shard]

Well, with a mono imaging train it's kinda pointless

You're already shooting relatively narrow portions of the spectrum

The distortion can be compensated for with registration

Even with OSC you can re-register the color channels

[slate falcon]

ye

[frosty shard]

The reason you want an ADC for planetary or visual is because you need to get those photons in all at once, and you may not be able to do so without the object rotating

[slate falcon]

i thougt there would be info loss tho

[frosty shard]

From the atmosphere absorbing light sure

But not from the dispersion

[slate falcon]

that makes sense

[frosty shard]

Also you need to adjust the ADC overnight if you want the best results from it

[slate falcon]

yeaa

otherwise it gives u ca

[frosty shard]

You'd need to both rotate it and adjust the altitude setting

[slate falcon]

awh :c

[frosty shard]

https://www.moria.de/tech/image-sensors/mtf/

I think this is a good read for those here

[desert locust]

gonna get chat to annotate this for me

I dont see a problem

[harsh matrix]

@slate falcon I introduced a ton of spherical aberration by tightening the secondary mirror screws i guess

So once again you were correct to say to loosen them up

[frosty flicker]

amy knows RCs better than you and doesnt even own one lol

[harsh matrix]

Cause they've modeled and ray traced them

I have not

[tight lodge]

I almost did

[harsh matrix]

guys

I noticed this Oiii egg when doing a comparison earlier

look at what was at its heart

https://tenor.com/view/hehe-gif-1840159130613519810

I basically imaged a wolf rayet nebula from another galaxy

[frosty flicker]

[harsh matrix]

how cool is that

that's incredible

[tight lodge]

You still need to improve your pixel peeping to this level

[harsh matrix]

No because then you cant see anything

Im so going to get more narrowband on M 33 this year

I must

There's so many cool ones in there.

now that ive seen that one

im seeing a lot of others that could very well have been made by wolf rayet stars too

M 33 has tons of these stars too btw

NGC 604 has almost 10

i accidentally imaged a potential planetary nebula in M 33 too

this is why resolution is the name of the game for me, above all else

globular cluster on top of a galaxy

guys

this year in the fall

how do we feel about doing a big M 31 mosaic from the bortle 3 site instead of M 33?

btw M 33 has a lot of blue globular clusters

at first i thought maybe it was an artifact of my processing or the narrowband addition

nope

these are just possible to see out in the wild

here's one in the LMC

[tight lodge]

That idea made hate M31
But I can cover it quite well in 9 pannels

[frosty flicker]

yall gotta bring an RC down here for the LMC

would be an absolute field trip for yall

[harsh matrix]

fr

i already know what all id shoot in the LMC and could get plenty of other ideas by looking at it some more

[slate falcon]

egg!!!!!

[slate falcon]

also did u manage to fix the noots weirdness

[harsh matrix]

I fixed the RC's weirdness

[slate falcon]

[harsh matrix]

the Quattro still has some incredibly minor weirdness that ill address a little later in the future

im going to leave it alone for now because ive done so much tinkering already

[slate falcon]

oofs

makes sense

[harsh matrix]

the RC looks to be mostly well collimated now at least

i think there's some pretty bad tilt though

makes sense considering the number of times this imaging train has been apart

i wouldnt doubt that something shifted after all that

focuser tilt specifically

i sure the tilt adapter has loosened a little

[slate falcon]

maybe

[harsh matrix]

yeah

tiny amount of tilt + some incredibly small collimation error

i think ill leave it alone

i spent a collective 4 or 5 hours (being conservative on the estimate) recollimating it

[crisp flower]

Bit Off topic but whats that Tool u use to See the tilt?

[harsh matrix]

that is the tilt analysis in ASTAP

@slate falcon there's still some weirdness, like reflections, in the RC data

I just remembered i never sealed the primary mirror cell back up

i think that's fine for now

i can fix it tomorrow

[slate falcon]

its good enough tbh

[harsh matrix]

the gap between the cell and the tube*

there's a minor light leak there

also light can slip in through the gap between the flat panel and the clamp that it holds into the scope with

so it could be from that too maybe

oh and my neighbors installed like 5 or 6 new security lights in their backyard that are about as bright as the sun 💀

that could be it too

[slate falcon]

eww

[harsh matrix]

yeah

it could be any number of things

in shape, scale, and appearance, these look a lot like the reflections my quattro had going on

i dont know what could be causing them other than the reducer or the shiny face of the flat panel catching some stray light

it doesnt appear to be in the flats actually

btw i got the sensor a little cleaner

[slate falcon]

[harsh matrix]

i took the liberty of installing my new 3 nm narrowband filters yesterday

[slate falcon]

ooo niice

[harsh matrix]

that vignette is only a fraction as bad as it used to be too

somehow everything i did improved the situation

So tonight I am just testing the RC again

i think tomorrow ill plug up the only leak left and then ill start shooting H-alpha tomorrow

on M101 with the new filter

I want to see if Oiii has anything as well, while im at it

ive never done an HaRGB image or an LRGB image of M101

[slate falcon]

:D

[harsh matrix]

I think ill set the real framing tomorrow as well

yeah there's a terribly subtle reflection

almost invisible

all of these ringing artifacts are technically internal reflections in the starizona reducer

yeah there it is

im just annoyed by the bright bar going up the middle of the image

that's really it

this could even be from the excess light of the moon

50% illuminated moon now

you know

honestly

this isnt too bad if it's their lights causing it

[slate falcon]

moon is too bright

it needs nerfing

[harsh matrix]

true

could still be the decoupler leaking too tbh

wouldnt be surprised on a night like this

[slate falcon]

yea

[harsh matrix]

i doubt the 3D printed plastic piece is flush against the metal blocking 100% of the light

and i say that because the background is almost the exact same as when i left it completely unblocked, just not as bad

[slate falcon]

ah

[harsh matrix]

unblocked on the right and blocked on the left

so it looks like i have a little bit more light proofing to do

i dont mind since i dont plan on collimatimg the rc any time soon ngl

[slate falcon]

not bad tbh

[digital nexus]

why don’t you just buy an RC

[frosty flicker]

Too slow for my liking. I want something fast

[frosty shard]

Oh yeah I discovered this during my loose secondary catastrophe

How'd you determine you had spherical aberration?

[frosty shard]

REEEEEEE GET OUT OF MY THREAD

[frosty flicker]

[digital nexus]

reducer

[frosty flicker]

Not faster enough

[digital nexus]

My rc6 is f/5.3 now. My 71f is f/6.9

my lens is f/5.6

how’s that not fast enough for people

[harsh matrix]

When the center of my field was in focus, the very edges were quite a ways out of focus.

[frosty flicker]

F4 is where its at for me. Or f2.8

[harsh matrix]

The HFR was huge too

[digital nexus]

Roki glazer

[frosty shard]

Spherical aberration is an on-axis aberration - that sounds like field curvature

[digital nexus]

You’d like the new Askar scope

[harsh matrix]

By loosening the secondary collimation screws just a little bit, it brought the entire field back into sharp focus.

[digital nexus]

F/3.8

[frosty shard]

but this does sound like spherical aberration

[harsh matrix]

It would be really strange if so because loosening the secondary fixed it.

[digital nexus]

@frosty flicker

[frosty flicker]

Have you seen the spot diagram for it?

[versed roost]

now thats a steal

[frosty shard]

I'LL TAKE 20

[digital nexus]

https://agenaastro.com/media/opti_image/webp/wysiwyg/ChatGPT_Image_Feb_24_2026_02_18_00_PM_1.webp

[frosty flicker]

Its worse than the minicat51

[digital nexus]

if it’s cheaper idc

[frosty shard]

wait it's only got a doublet objective...

[digital nexus]

I’m looking to get either this 50P, an FMA180 Pro, or an SQA55

[digital nexus]

It has 4, but only 1 SD

[frosty flicker]

Its petzval. It had 2 sections with each having 2 glass lens

[frosty shard]

You can have a triplet objective with a Petzval design, the Askar F series for instance

Or technically Petzval-like

[digital nexus]

It’s the same thing

But this has SD glass not ED

I’m looking for a wide field scope so il be following this one closely.

FMA 18 Pro, SQA55, 50P

I’m an Askar Fanboy

Il put some Askar stickers on my RC6 to make it pretty

[frosty shard]

The 50P has 3x to 4x the RMS spot size on-axis (wavelength dependent)

[digital nexus]

I care more for real world examples

The math bores me

[frosty shard]

Well just from looking at the spot diagram, unless it's pretty damn cheap, you'd be far better off with the SQA55

[frosty flicker]

It wont be worth your money

[frosty shard]

The real-world tests will probably not fare as well as the modeling

[digital nexus]

Depends the price

[frosty shard]

If it's like a $300 OTA, then what the hell, I'd get one

[digital nexus]

I’m thinking $400

[frosty flicker]

Na like $700

[digital nexus]

That’s the price for an SQA55 so I highly doubt it

[frosty shard]

The SVBONY SV503 70mm quadruplet, a 2+2 Petzval design with similar specs to the Askar 71F, is $400

[digital nexus]

lol

Sure

Ok

Good joke

[frosty shard]

What's the joke

[digital nexus]

it isn’t nearly as good as the 71f lolll

[frosty shard]

It's a 70 mm f/7 refractor, just a 2+2 rather than a 3+1 layout

Oh yeah of course

But I would hope that the 50F is cheaper considering that the SV503's spot diagram is actually better

[digital nexus]

It has to be cheaper than a SQA55, and probably more than the FMA180 Pro

[digital nexus]

This is the fma180 pro

[frosty shard]

well the FMA180 Pro's spot diagram is at a 2x finer scale, and the RMS/geometric radii are better

I'd take that over the 50P any day of the week if they were the same price

[digital nexus]

Fma180 pro is $440

that’s why I’m looking at it

cause I want a cheap widefield refractor. And I don’t want a Roki

[frosty shard]

Field too wide? Or some other reason

[digital nexus]

Lottery lens

And I’m not a fan of the mounting solutions

Fma180 pro would end up being cheaper since I don’t need rings

[tight lodge]

Bro... this is a reflectors only thread

[sinful sapphire]

That’s technically an achromat

[harsh matrix]

2 days will be my 1 year anniversary of making dark sky site trips.

This incredible photo being one of the fields I shot then.

[frosty flicker]

but tbh if someone was selling an RC cheap and nearby me with accesories i would buy it

ive been wanting a deep galaxy rig for a while

[harsh matrix]

Galaxies are the best

That is an undebatable fact.

This is my proof.

[tidal hearth]

Nice, I started capturing some Ha of that region yesterday

[digital nexus]

Galaxies are mid. Nebulae are where its at

[crisp flower]

Galaxies are awesome

[digital nexus]

but nebula are better

[crisp flower]

no

[slate falcon]

m40 is more intresting than half the bebula out there

[digital nexus]

sure buddy

[slate falcon]

im getting 100 hours on m40 for a reason

[quartz meadow]

cause of them galaxy neighbors like NGC 4290?

[slate falcon]

nope

for the 2 stars

[stiff mason]

Guess what galaxies have nebulas in them and globular clusters its literally two bird one target

[stiff mason]

Why is there a random star in the messier catalog

[desert locust]

While looking for another object, messeir thought it was the object

[stiff mason]

Lmao why not revert it

[slate falcon]

souvenir

[frosty shard]

I wonder if you'll change your tune when you get the RC cooking

But I also gotta say

While nebulae take a long time in an RC, it's super satisfying getting close-ups

[versed roost]

int?

[harsh matrix]

4 and a half hours, roughly.

[digital nexus]

no

I hate processing galaxies. The rc won’t change that

And I’m not saying I dislike galaxies, I just prefer nebula

And I plan on doing lots of nebulae with my rc6

[digital nexus]

My rc6 reduced is more than an entire f stop faster than my refractor lol

@harsh matrix I’m thinking of setting up the rc6 without collimating…. How bad would this be

[frosty shard]

Not terrible tbh, unless it's way out of whack you can probably get most things working to start

[digital nexus]

It probably is

Cause when I got it, the mirror was actually moving with any pressure on the focuser / spacers

[frosty shard]

Primary or secondary?

[digital nexus]

I fixed it by adjusting a Collimation screw, I thought it was a locking screw.

The seller sent me an Astro-Tech RC6 manual and the screws are reversed lol

[digital nexus]

Primary was floppy, I also hopefully did a bit of Collimation on the secondary

[frosty shard]

Either way you'll probably need to have the camera and all set up to collimate it, unless you can collimate with an eyepiece

[digital nexus]

It’ll probably be easier to do it with a camera

[frosty shard]

Eyepiece is easier for rough collimation

(and if you need to adjust the mirror spacing, but that's less likely)

But for good collimation a camera is better

[digital nexus]

So I have hex keys or Allan wrenches, whatever they’re called

How can I make sure I don’t drop it :/

any tips lol?

[frosty shard]

Don't drop them on the mirrors?

It's not something I've ever worried about tbh

[digital nexus]

For the secondary yes, but the primary I mean ground

Like mine are black. It’ll be lost lol

I need a handle or something

[frosty shard]

Honestly I was thinking about something similar and I want to get myself some glow in the dark tape

[digital nexus]

Ooh that’s a good idea

[frosty shard]

In my case it was about having some for when I take my scope out with my friends who aren't into astronomy/don't have good night vision skills

[digital nexus]

Are the locking screws and Collimation screws different size keys?

I can’t remember

[frosty shard]

Unfortunately, they are

[digital nexus]

No that might be a good thing

So you don’t accidentally do the wrong one

[frosty shard]

Good point

I guess I only mess with my collimation in light polluted areas so this isn't as big a deal

I actually should get a set of Allen keys because the one issue I've run into is that the focuser extensions don't provide enough clearance for a multi-tool or ordinary screwdriver

That's a much bigger gripe I have

[digital nexus]

I bought a big kit on Amazon for like $6 and they’re heavy metal

[frosty shard]

I'm gonna make sure to get a set that isn't black lol

[digital nexus]

yeaaaa

I just bought glow in the dark tape

Different colors

Il put a small piece next to each type of screw (locking / collimation)

Color code it

[frosty shard]

Wait is it glow in the dark or fluorescent tape? I've seen some confusing listings

[digital nexus]

Oh….

[frosty shard]

I've been trying to see if I can get multicolored glow in the dark tape but that does not seem to be common

[digital nexus]

Let me cancel my order real quick…

[digital nexus]

Hey

Guess what

It’s $300 LOL

[slate falcon]

tbh look at the sv535

[digital nexus]

lol no

It’s twice the price, and you cant use a filter drawer iirc

[slate falcon]

wait whaaat

[digital nexus]

Not enough back focus i think

I dont remember completely

[digital nexus]

What plate solving method do you use? @frosty shard

I heard PlateSolve 3 works well at long FL

@harsh matrix

[frosty shard]

ASTAP + D80 catalogue

[digital nexus]

Oh that’s what i have been using so that works out

[harsh matrix]

@frosty shard any ideas as to the origin of this junk?

The spot in the middle still seems to be a baffling issue but I cant improve on that any more.

[frosty shard]

Honestly, I can't say...since I have the version with revised baffling I have never really dealt with these kinds of artifacts?

[harsh matrix]

I'm on my own ig.

There's only a handful of things I can try now.

I think the smaller sensor of the 533 avoids these issues.

Like with the quattro, a larger sensor is asking fo more problems.

Maybe it's time to give up on the idea of using a 571 on this scope.

Thought neither of my other cams are free so im screwed.

[crisp flower]

I fear i have joined Ring of death-club

[harsh matrix]

Yes you have

That's the baffling issue in question.

[digital nexus]

wats wrong with it

[crisp flower]

Well thats Just great..
Guess i'll try and ignore it best i can

[digital nexus]

today was supposed to be first light with the rc6, but guess what arrived? clouds

[harsh matrix]

Do you see the crater?

[crisp flower]

Always Like that xd

[harsh matrix]

Ive exaggerated mine like crazy here

But same thing is in their image.

[digital nexus]

I see yours but not lime’s

[slate falcon]

crater isnt big enough

[digital nexus]

Anyways are flats not correcting for that?

[crisp flower]

Its a Donut in the lower right

[harsh matrix]

A big donut

[digital nexus]

I don’t see it

[harsh matrix]

Like entire bottom quarter of the frame.

[digital nexus]

I don’t see it

Does this really affect the image

[harsh matrix]

Yes

[digital nexus]

It seems like flats should take care of it

[harsh matrix]

They don't

I wouldnt still be having issues if they did.

Lime used flats

It didnt fix that issue either.

I see a very clear pattern here.

[digital nexus]

How bad is it at the end of processing

You can’t hide it with careful processing? Masks?

[harsh matrix]

You can try

[crisp flower]

If i dont use Flats its Not noticable i think but once i do its clearly there

[harsh matrix]

But if you get enough integration, it doesnt matter

You will always see it no matter what you try to do.

[digital nexus]

and why are you guys suffering from this

What sensor

[crisp flower]

Tried to hide it by darkening the bg

But i still See it clearly

[digital nexus]

I don’t lol

[slate falcon]

its from the rc itself

[digital nexus]

yea I get that

But why

[harsh matrix]

I do.

[harsh matrix]

If we knew the answer, I could have fixed it already.

[slate falcon]

i feel its presence even with my brightness all the way down

[digital nexus]

What sensor size

[harsh matrix]

Lime has a 533

[crisp flower]

Yea sadly xd

[harsh matrix]

Ive seen it with both my 533 and 571

[digital nexus]

What RC

[harsh matrix]

Sensor is irrelevant.

Like has a 6

I have an 8

Both scopes have the problem

[crisp flower]

Im at an 8" as well

[harsh matrix]

My 6 had it too

[harsh matrix]

You do have an 8?

Tf

I thought you had a 6

Cool

[crisp flower]

Yes

[harsh matrix]

8 gang lfg

[crisp flower]

XDDDDD

[harsh matrix]

[crisp flower]

Im pretty much running the Same train as brain

[slate falcon]

brain train

[harsh matrix]

I guess im ripping the apex off once again.

Hopefully that makes a noticeable difference

[harsh matrix]

So you're at native?

[crisp flower]

Jup

[harsh matrix]

Yeahhhhh, I had the problem at native too.

[slate falcon]

looks like a ronchi test or howere you spell it

[harsh matrix]

Im at the point in diagnosing the issue that everything i seem to do is making it worse.

[slate falcon]

[slate falcon]

i think you should try night sky flats

and see what happens

[harsh matrix]

If it works it isnt worth doing in the long run

Thats why I havent done it

If i was using an OSC cam it would be straightforward

[digital nexus]

What

The hell

Is a night sky flat

[slate falcon]

you havent heard?!

[digital nexus]

no

[harsh matrix]

Do you have the carbonstar rc8?

[digital nexus]

What an FOV

[crisp flower]

I have a steeltube one

[harsh matrix]

How new or old?

[crisp flower]

Uhm good question tbh
I bought it new last August, as for how new it is in Terms of when it was built, i have No idea

[harsh matrix]

What brand is it?

[crisp flower]

Omegon

[harsh matrix]

Hmmmm

Im not sure when Omegon popped up in general.

That's a mixed bag for sure.

Does the center of the spider look like this? Or is the size of this plate and the spacing of the screws different?

This changed some point recently so depending on what yours looks like, it could date the scope.

[crisp flower]

Looks Like this (god the flash Made this Look Bad)

[harsh matrix]

Alright your's is a new model

And it matches Brain's

Meaning both you of should eventually see the crater.

Unfortunate.

So model and age appear to be irrelevant.

[crisp flower]

Very

[harsh matrix]

@runic violet I'm not the only one.

[digital nexus]

how do u know

[harsh matrix]

My RC8 was made in or after 2017 but not much later.

The Carbonstar RC8, a new model of the GSO closed tube RC's, has that smaller spider with the closer screw spacing. Mine does not. Which means the spider changed some time after 2017.

Lime's RC matches that or the Carbonstar which means that it is roughly as new or as old as the Carbonstar line.

That's how I know.

[digital nexus]

is there a new model of the rc6?

[harsh matrix]

I have no idea.

We dont even know if anything else changed when the spider changed

The crater in Lime's image suggests that only the central part of the spider changed.

And nothing else.

[digital nexus]

FIRST LIGHT

FIRST LIGHT

SOON

once the north is clear of clouds

[tall summit]

You shootin'?:)

[digital nexus]

yep

Not collimating, just gonna see what happens

[tall summit]

Subs!! Post a sub

[digital nexus]

What app do you use for Collimation btw

Is it ASTAP i can use?

[tall summit]

I am in asiair mini world, dont know about that

I have build myself a cheap OCAL-ish device, and use that with an app called "Collimation Circles"

I say allign/center everything visually using collimation cap or cheshire, that should get you in a ballpark to start with

[harsh matrix]

You know, as bad as it is, it's also a good thing in a way.

It means that the crater isn't some weird one off issue with my particular model, and it proves to everyone that I'm not making it up or fabricating it somehow.

[frosty shard]

I don't use an app, I just use the NINA preview to evaluate the star shapes. But you might find MetaGuide useful

[frosty shard]

We have similar imaging trains so now I'm concerned...

[harsh matrix]

You should be.

[frosty shard]

@crisp flower @harsh matrix here's the one bit of evidence I have of the same issue, but this is it. I took this data on a full moon and my flats ended up being bad, so idk if this is really the same thing

I can be confident that this artifact isn't from the mirror at least

Also @crisp flower what focuser are you using?

[digital nexus]

Bruh I can’t find focus

Idk where I need to be at all

[harsh matrix]

That's the same issue alright.

Afaik

[harsh matrix]

Probably need to go in farther which means you need to remove another one of the M90 tubes.

[digital nexus]

I only have 1 m90 tube

And I went in and out all the way

noting

Can’t see any stars either way

[harsh matrix]

Bad flats will make it appear immediately, good flats only delay its onset.

You are never fully liberated of it.

[harsh matrix]

Yeah remove it.

That's 1 too many if the reducer is a 0.67x and you are using it correctly

Did you remove the extension on the back of the reducer or did you keep it on?

[frosty shard]

Well what happens if you stack without flats?

[harsh matrix]

I havent tried.

Not on the data with the crater, anyway.

Actually I may have

[frosty shard]

(That'll determine if the issue is due to the flats or the lights)

[harsh matrix]

Hmmmm

Now I dont remember if I tried without flats

I can give it a shot when im home in about 20 or so minutes.

[digital nexus]

It literally can’t attach to the scope without it

[frosty shard]

Wait...is the draw tube too long?

[digital nexus]

Yes

[harsh matrix]

Uhhhh

Yeah

[frosty shard]

I just realized someone I know may have had this issue

[harsh matrix]

Actually I think it is too long

That focuser has like 90 mm of outward travel which makes it much longer than that when racked in.

Mine is only 90 mm long and racks out to 50 mm max iirc

[digital nexus]

So what do i do

[frosty shard]

You could always try without the reducer

[harsh matrix]

And it barely fits then

Id try without the reducer.

[digital nexus]

So basically my focuser is incompatible if I want the reducer

@harsh matrix What spacers for non reducer

50mm and 25mm?

[harsh matrix]

You could still use the reducer but use it at 0.8x reduction.

To do this i think you need a 25 mm spacer

[harsh matrix]

Since your focuser drawtube is so long, id run with a 50 mm

Do you know roughly how long the body of the focuser is?

[digital nexus]

Long

90mm draw tube

[harsh matrix]

then a 50 mm extension tube should do the trick to reach focus at native

now that i'm home, before and after graxpert

weird as hell background ngl

there's still a ghost of the baffle issue in the center

annoyingly enough

here's the ABE'd flats