Ritchey–Chrétien enjoyers thread

[candid flame]

This is super fascinating bit I really gotta go to bed guys. It's 2am and I have lectures at 8

[frosty shard]

Yeah go to sleep jeez

[candid flame]

But we will get to the bottom of this and invent a perfect measure of quality someday trust

gn

[frosty shard]

When you expose for longer, or stack images, you effectively scale up the spatial frequency information proportionally with the MTF. Finer features show less contrast than coarse ones

(That is not rigorous please don't kill me)

But with Gaussian noise (perhaps that's the sensor's read noise) you're fighting against a flat line in frequency space

Poisson noise isn't Gaussian (it's going to depend on the image features themselves), but with a uniformly illuminated background you get baseline noise that's roughly Gaussian

[harsh matrix]

What if the sky illumination is like mine?

Where there is a noticable drop in signal over the course of only 3 hours

[frosty shard]

Wait how is the signal dropping

[harsh matrix]

Extreme light dome variations

[frosty shard]

Ah

[harsh matrix]

The region right above my house is dang near bortle 7 but everywhere around me is some variation of a high bortle 8 or 9

With visible and obvious increases in magnitude btw

[frosty shard]

Well, that's where statistics gets a little funky when you stack due to normalization

[harsh matrix]

I can see the domes inside of my own dome

That's how much brighter those spots are

[frosty shard]

Poisson noise is always going to be present, and a bright background increases the noise, which you can't get rid of by just subtracting the background

The best practice would be to weight the subs in part by the baseline illumination

[harsh matrix]

💀

It changes roughly every sub

[frosty shard]

I mean I'm pretty sure that's what PixInsight does with WBPP

[harsh matrix]

I am pretty sure it goes off of psf signal and not object signal

With the way mine us set up

[tight lodge]

Damn... I did not expect you guys to go that deep into it🤣

I just wanted to point out that a 130PDS can in fact compete with you all

[frosty shard]

Yet you still can't match my aura

Wait does that actually work lol

It might be too high in quality

[tight lodge]

Bruh💀

[tight lodge]

You sure that Aura is not light pollution?

[mortal vale]

This thread has seen more conversation than my first 1 year relationship

[silver ibex]

I love how in this thread there's more than half of the messages sent in the planetary imaging thread, while being less than a third the age

[tight lodge]

#1326833769495269376 message

Yesterday alone everyone went crazy over this image

[quartz meadow]

that was something

[tight lodge]

24037 messages

[harsh matrix]

@frosty shard just so you know what the light pollution is like near zenith vs the end of a night

left is near zenith, right is around 30 degrees

[frosty shard]

Big oof, those gradients

[harsh matrix]

told you

you can easily see by eye just how much worse things get over 3 hours

[tall summit]

I started reading a bit and gave up:)

[stiff mason]

Btw how thick are your spider vanes just out of curiosity

[frosty shard]

About 2 mm

[stiff mason]

Nice

[harsh matrix]

@frosty shard are there any light leaks in the Askar OAG that you know of?

[frosty shard]

None I'm aware of, do you suspect one?

[harsh matrix]

maybe?

this is a green flat on my redcat which has the askar OAG on it

that circle won't fully calibrate out

[frosty shard]

I don't know what OAG @tight lodge has, but this may be of interest to him too

[harsh matrix]

a light leak is the only explanation i can think of

im not sure it isnt the filter wheel still, though

[frosty shard]

Which filter wheel are you using?

[harsh matrix]

ZWO 8x1.25" EFW

kind of a better idea of what im dealing with

ive saturated it a butt load so you can see the remnant better

even DBE cant get rid of it

[tight lodge]

I have the PlayerOne 2" OAG

[harsh matrix]

same scope but from lasst year

weird

they kind of look the same but inverted as far as what color the patches show up as

[alpine flame]

Show me the imaging train

[frosty shard]

I have absolutely been shooting at the wrong gain...holy crap

[crisp flower]

u have been Shooting at 100 right?

[tight lodge]

I think that's the biggest drawback for Touptek. They give you more options than what you actually need

[tight lodge]

https://diffractionlimited.com/flat-fields-stray-light-amateur-telescopes/

@harsh matrix @frosty shard you might find this interesting

[frosty shard]

I actually have seen this before, and I am curious about how well that black paint may reflect IR

[tight lodge]

the thing is, the interior of my focuser draw tube is flocked and not painted

and i get similar bright circle in the middle as you guys

[frosty shard]

I do not get that anymore

Ever since I flocked the M56 adapter

Here is an infrared flat I just stacked

[high aspen]

jolly :D

[high aspen]

sooo mayny ciocle

[frosty shard]

...how do I have walking noise...

[harsh matrix]

Did you dither too few times?

If at all?

[frosty shard]

Nah, these are 15 second exposures and I dithered every 4 frames lmao

I think I know what happened

It was windy, and these frames seem to have biased dithers

All along one direction

Thankfully it will be easy to recover 40 minutes of IR data

[harsh matrix]

Oh no

[frosty shard]

Tbh it's not too bad once I combine it with the H-alpha data

[high aspen]

pretty :3

[frosty shard]

100 gain (left) vs 200 gain (right). Hard to directly compare due to different histogram transforms, but I think this was the correct call

[high aspen]

@tight lodge does this beat your 3d blender model

[high aspen]

is right less noisy?

for similar signal

[frosty shard]

Regardless, I do like the granularity. It's nice to have full manual control over the sensor

[frosty shard]

Yeah

[high aspen]

its a class cass tho btw

[frosty shard]

Both are 15 second exposures

[high aspen]

higher gain and less noise???

[frosty shard]

Yeah

You have less quantization error, and the read noise is a smaller fraction of the image

[frosty shard]

Oh man it's actually really significant

Gain 100 above, gain 200 below

[high aspen]

why tf is gain 200 better???

[frosty shard]

Because you're counting all the photons, not just half of them

[high aspen]

buh

[candid flame]

that's not how gain works?

[frosty shard]

Or 1/2.15 of them, at gain 100 with my camera

[high aspen]

thats what i thought ngl

[frosty shard]

I could be misunderstanding something, please pop off

[high aspen]

isnt gain the amount of current sent through the sensor?

[candid flame]

to my understanding, gain is basically just a transformer scaling up the voltage before converting to ADU

that way it can be read more precisely, but you have lower dynamic range

so basically a trade-off between quantization error and dynamic range

[high aspen]

that waht i meant yea

[high aspen]

also increases sensor noise bc of electrons being counted as light

[frosty shard]

Which noise specifically? Quantization noise goes down

[candid flame]

dark noise and shot noise goes up (measured in ADU)

you're basically just multiplying the signal and the dark current by a constant

so noise goes up, but SNR remains constant

i think read noise remains constant tho, because that comes after the amplification, so SNR goes slightly up if read noise is not swamped

(measured in ADU)

[frosty shard]

Yup, highly relevant in the case of my 15 second IR exposures

[candid flame]

oh yeah, you can actually see quite a bit of horisontal banding too, which is almost purely caused by read noise

[high aspen]

how do you read noise?

[frosty shard]

It actually looks a little worse at gain 200

[candid flame]

yeah oddly enough

but maybe it's just the stretch idk

[frosty shard]

So it might not be read noise in the usual sense, but internal interference

I should check the camera USB speeds, because that seems to be one of the factors that causes banding

[candid flame]

oh really? i've never heard of that causing issues

[frosty shard]

Yeah, it's a thing in a lot of cameras. QHY even suggests changing it on their site

But I'd rather shoot at gain 200, even with more banding and less dynamic range, and just double my frame count, because stacking will restore some of the data's range

[frosty shard]

to be clear "read noise" is a term for noise that is intrinsic to the sensor. As opposed to shot noise (or Poisson noise) which is intrinsic to the quantized nature of light

[candid flame]

second graph is in ADU right?

[frosty shard]

Excellent question...

https://www.touptekastro.com/products/atr533m?variant=49834614915384

Here's where the graph comes from

Usually read noise number are cited in electrons, so I assume that's the unit

[candid flame]

read noise should definitely go down in electrons tho

otherwise there would be no reason to increase gain

[frosty shard]

I'm wondering if the amplifier starts having a significant noise contribution that scales with the gain

[high aspen]

so 200 best?

[candid flame]

huh, maybe

[high aspen]

or 300?

[candid flame]

i guess there's still the advantage of less quantization error ig

[frosty shard]

I'd have to do more testing, but it seems like with the Touptek ATR533M, unity gain is 200 in high conversion gain, high full well, and low noise (ultra) mode.

The graphs suggest lower read noise at gain 316 (gain 316 is equivalent 0.6 electrons/ADU conversion)

[candid flame]

actually i don't understand the unit

how is it electrons/ADU and not just electrons?

[frosty shard]

clarified it

[candid flame]

i still don't understand

how is it different from just electrons?

[high aspen]

maybe its electrons over adu

[frosty shard]

Conversion gain refers to the number of electrons a single ADU corresponds to. So unity gain is 1 electron/ADU

[candid flame]

oh yeah i understand that, but how do you measure noise with that unit?

wait I just can't read lol

[frosty shard]

Ok I think we're on the same page again

[harsh matrix]

@frosty shard something I hope to study more once my RC goes to Starfront is stellar streams and galactic halos.

Stuff ive never been able to pay attention to from here.

Not even really from the dark sky site.

Since a lot of them are so faint that you have to get like 20+ hours of lum, which is not a achievable from the dark sky site with the rest of the stuff going on in my life.

[digital nexus]

The adapter I need for my RC6 is gone

mail lost it

USPS’s reputation meets expectation

[harsh matrix]

Ugh

Wtf

[digital nexus]

It’s been in transit from Texas for 3 days….

Supposed to be delivered today

I can’t afford an M63 adapter soo great

[harsh matrix]

Hmmmm

Well lets see

They wouldn't have been moving yesterday

Maybe not even overnight last night.

[digital nexus]

Oh sorry it’s been in transit for 4 days

Like it hasn’t been scanned in the next facility

After 4 days

:/

Hopefully it’s cause of the holidays. I really don’t want to spend $40 on an adapter

[harsh matrix]

Definitely is

It disrupted one of my purchases too.

Also they suck at keeping information current.

I wouldn't worry unless somehow a week flies by with it allegedly being in the same place.

[tight lodge]

Gain 0 vs gain 210 (unity)

[frosty shard]

You have a 585 though right

The Touptek version has different settings

[frosty shard]

I'll loop in @crisp flower since I saw he has an Omegon 533M

[tight lodge]

P1 settings are very simple.
And tbh, I still don't get it why would you need the access to all those settings on Tpuptek

[frosty shard]

I know offset can drift, but if gain can drift as well, I'd rather have a camera that does not automatically switch modes

[tight lodge]

I never heard someone having issues with that

[frosty shard]

I mean you don't need to have access to all those settings to get a good image

I just prefer to have fine grained control over the camera

It's like car enthusiasts who have cars with manual transmissions

[tight lodge]

Speaking of that, driving a manual transmition in a busy city makes you want to set the damn thing on fire

so you see? each has it's place.

[frosty shard]

@harsh matrix this might explain why HFW mode won't calibrate
https://www.cloudynights.com/forums/topic/910209-touptek-26000-kpa-imx-571-sensor-analysis/

https://forums.sharpcap.co.uk/viewtopic.php?t=9129

although I haven't had calibration issues (at least not caused by the camera itself), the mode is usable if you bump the gain up

but I'm not sure if you actually want to use that particular mode

It makes more sense with the ATR533M judging from the documentation (you achieve the lowest read noise)

[tight lodge]

@harsh matrix , do you remember when i was talking about mirror actuators for collimation? Look what i stole from JWST

[harsh matrix]

wtf

[tight lodge]

What? This thing has micron precision

[stiff mason]

Oooh

[high aspen]

wow, the diff actually isnt that big

[harsh matrix]

i know lol

i didnt expect it to look like that

how work

[tight lodge]

Because it's the same😂

[high aspen]

its a cc and an rct???

not the same

[tight lodge]

Can you tell the difference from the pictures alone?

[high aspen]

yes

[tight lodge]

how

[high aspen]

the secondary of the rc is about 1 to 2 cm bigger

the tube protecting the secondary from stray light is longer in a cc due to the secondary being firther away

the cc tube is longer

and the tube protruding from the focuser into the ota is also smaller in the cc

[silver ibex]

One has a red dovetail duh

[high aspen]

if i somehow couldnt use this and i had both scopes irl to look through but i didnt know which is which i could use the aberrations at the edge of the field to tell

a cc only has astigmatism

and thats kinda easy to spot

[tight lodge]

Why there are no fast RCTs?

Imagine an 8" 650mm RCT

That would be the ultimate telescope

[digital nexus]

USPS “attempted delivery” stfu no you didn’t

“Your item is being held at the post office. This is at the request of the customer” yea shut up usps

[high aspen]

2d histogram >:3

[silver ibex]

USPS? More like "UPS, we made a mistake"

[sinful sapphire]

thats exactly how "oops" is spelt in german

which is also why UPS is memed so much

theyre so

bad

i hope my camera comes home safely

[high aspen]

3d histo

[digital nexus]

What’s the chance this is good

[silver ibex]

-1

[digital nexus]

why

[silver ibex]

There's absolutely no way that a 0.5x is good, the fact it's 30$ doesn't help whatsoever 💀

[digital nexus]

idk I kinda wanna try it

what reducer would you recommend then

[silver ibex]

For a RC?

What brand is yours again

[digital nexus]

GSO

[silver ibex]

https://www.teleskop-express.it/riduttori-correttori-spianatori/3187-ccd-riduttore-067x-per-rc-teleskop-service.html I've heard ok things about this one, sorry for the italian website

[frosty shard]

Hmm...I don't use my reducer, and I have one of the Apertura 0.67x ones

what's your budget for one

[digital nexus]

I think I’d rather take my chance with the $30 0.5x 💀

[silver ibex]

I'm willing to bet it's the same thing but rebranded

[frosty shard]

Yuppers

[digital nexus]

I’m just exploring. I want something cheap but not garbage

[silver ibex]

Idk why you are expecting precise lenses like this to be cheap lol, to me that is cheap actually

[digital nexus]

What’s the worst that can happen

[silver ibex]

I can try looking for a cheaper one but idk

[silver ibex]

You waste 30$

[high aspen]

the only 30 dollars i would waste is on a nangtong foric filter

[oblique sun]

i have this

it is actually good for visual

i bought it for $5 tho

[digital nexus]

I don’t care abt visual

how’s it for AP

[oblique sun]

dont buy it then

[digital nexus]

🥺

[oblique sun]

also you need to try visual

[digital nexus]

I will but like

Is it gonna be any better then my 6” dob

[oblique sun]

what

[high aspen]

its insanely good for ap

[digital nexus]

I don’t believe you

[high aspen]

if you do 1nm pass narrowband

[digital nexus]

I have a 6” dob

The heritage

will that be better or worse for visual

Probably the same no?

[high aspen]

it is

[oblique sun]

better or worse than what

[digital nexus]

My rc6

[high aspen]

just not if you want to use more than 1nm of light

[oblique sun]

ik you have a 6" dob but the question didnt make sense

[oblique sun]

similar

id prefer the heritage bc its easier

[high aspen]

class cass is the best for visual

[silver ibex]

Probably better cause AZ is nicer to handle and less CO

RCs are made for photography

[high aspen]

https://www.cloudynights.com/forums/topic/935953-an-apology-to-the-nantong-foric-optical-glass-factory-store/

https://www.aliexpress.com/item/1005010350250117.html

iron 2 filter 😭

[frosty shard]

25 nm wavelength though 💀

[high aspen]

not bad for 30 tho xD

and almost feasible for osc

[frosty shard]

I feel like it would be cool to get off-band narrowband images and use them for continuum subtraction

[high aspen]

wdym by offband?

[frosty shard]

So when you continuum subtract an image, you're subtracting the continuum contribution to the band of interest from the true narrowband signal

[high aspen]

yea

[frosty shard]

When you do this with broadband data, you're approximating the continuum contribution by scaling down the magnitude of the broadband channel to match the magnitude of the broadband contribution to the narrowband channel

Which is generally not a bad idea just because you get significantly less noise with a wider filter

But I'd be very interested to see what happens if you subtract the signal from an O-III filter from this one

[frosty shard]

Also, this would actually be a good comet filter

It covers the Swan bands

[high aspen]

@scenic mango

[scenic mango]

they make specialized comet swan filters

[frosty shard]

Not the best comet filter, but good enough to enhance ion emission

and cheap

[frosty shard]

Got any recommendations?

[high aspen]

honestly may get when i get mono

would be so cursed

FIH pallete

[frosty shard]

What's F lmao

[high aspen]

fe

iron

[scenic mango]

there seems to only be the baader filter lol

at least for "proper" swan filters

[frosty shard]

Oh I was reading I as iron oops

[high aspen]

😭

iron ir hbeta

probably halpha

bc longwave

[frosty shard]

That's 15 nm, so definitely better, but for the price I'd take the Nantong to start lol

[desert locust]

pick it up yourself if your impatent

[digital nexus]

I am?

Because I have to?

did you not read my message?

They lied multiple times. They didn’t attempt delivery (they are a delivery service). And they are lying, holding my package saying it was my request (I didn’t request that)

[desert locust]

did you call them

[digital nexus]

Why would I call them

that ain’t gonna do anything

[desert locust]

hm

[digital nexus]

Anyone who works at usps hates themselves and makes it their job on being useless

[desert locust]

lol

[scenic mango]

how do you even turn these into astro filters

[high aspen]

you just put a holder on them

[scenic mango]

damn

[tidal hearth]

what are they for touptek?

[tall summit]

G@digital nexus have you received your focuser adapter?

[digital nexus]

It was delivered today

[tall summit]

N8ce!!

[digital nexus]

Thought I’d have to pick it up at the post office but I guess USPS decided to… you know. Deliver

[digital nexus]

I’m going to test my 50mm guide scope on my Askar, hopefully guiding will be around 0.4-0.5”. Once I am confident in that, it’ll be time to mount the RC6 on the Ragdoll and get rolling

The weather has been absolute garbage for the last month so it might be a while

[tall summit]

I did get to try my new 60mm scope

Although it was pretty windy, it worked great

[digital nexus]

What mount again?

Any issue with Flexure?

[tall summit]

I got into sub 0.4 during the moments of calm

Not that I can notice

Cg4 with onstep

[digital nexus]

I need to be under 0.56”

[tall summit]

I mean, if my mount can, yours should be fine too

[digital nexus]

What guide scope do you have

[tall summit]

@digital nexus I got Astromania 60mm F4

[digital nexus]

Probably identical to the SVBONY one I got but larger

[frosty shard]

Reuploading this here just because I need to share it in a different format with someone

[digital nexus]

What did you use for the timelapse

I’m thinking of doing one with my dslr

[frosty shard]

I borrowed a Canon EOS R6 from my university library, lens at f/4, 24 mm, ISO 6400

[digital nexus]

How often did you take an exposure

[frosty shard]

Whoops, 15 second exposures every 20 seconds

This was at a high Bortle 4 site

[digital nexus]

I got a nifty fifty

Wonder if it’ll be too long

guess I can just move it back a bit idk

[harsh matrix]

@frosty shard I printed a little mask for the front of my reducer

shouldnt need to risk destroying the front element anymore

[frosty shard]

Ah, now that's a better idea

I guess you could print one that threads in

[harsh matrix]

I didnt have that idea lol

I have to tape it on

Maybe I can make another one in the future

In general it cant be too thick and if I want to make one that threads one, it could be too thick.

It's about 3 mm thick which is occupying a mil or a mil and a half of the outer edge of the reducer.

Yo now that's an idea

I could test something like that for my quattro's coma corrector

[harsh matrix]

Fixed?

There's only one way to find out

[harsh matrix]

@frosty shard update to the RC

It can handle APS-C without vignetting at native

In lum

I get vignetting across the board with a reducer.

[frosty shard]

Not surprised considering how big of a chungus the secondary is lol

I think my next major upgrade to the RC will be a larger sensor

[harsh matrix]

Hell yeah

Btw gonna have to take your idea to thread the mask on

There's no way it can work with tape lmao

It wont fit with the baader click lock

[frosty shard]

Ideally I'd wait for a Starvis 2 sensor to drop but honestly idk if I will...I might just go for an IMX571.

[frosty shard]

Ah, that's a problem

[frosty shard]

Also I'm prioritizing a few other things before a sensor that I would consider minor upgrades:

• Touptek/bolt-on OAG
• Gemini EAF
• Antlia IR pass

Also I think a mirrorless camera and small refractor would come before a sensor upgrade

[harsh matrix]

I used electrical tape and even though it's a tenth of a mil thick at the most, it cant go in the baader

[harsh matrix]

so, there's more contrast in the corners

i dont have any clue if that is going to be enough to fix what i was seeing

i guess the problem was subtle enough that it only showed up after stacking

it's a good thing that the corners are both brighter and darker where there's light there because it was undercorrecting before

that means this one could correct all the way

[tight lodge]

It does look like a very symmetrical pattern

Are the edges of your mirrors masked?

[harsh matrix]

no

but that pattern does not exist on a flat taken at native focal length

[tight lodge]

Could that be the reason for the bright circle?

[harsh matrix]

there's very even light fall off from the center to the corners with no vignetting whatsoever

[harsh matrix]

highly doubt it since it isnt present in flats at native focal length

the flat field errors above are only ever present with the reducer

(this is why I am beginning to think reducers are bad and should never be used)

[tight lodge]

Well that's what I'm saying. Maybe with the reducer, the sensor is now able to see the edges of your mirrors

[tight lodge]

I heard that reducers like to mess up the light cone

[harsh matrix]

I doubt it

the secondary maybe but not the primary

[harsh matrix]

they 100% do

[tight lodge]

That's my case as well. The edge of the secondary has a chamfer that is creating some weird artifacts

I might design a shroud for it eventually

Kinda like how the RCTs have the secondary mirror baffle

[harsh matrix]

idk if it's the secondary mirror, there's nothing i can do since the secondary is baffled already

there's bound to be some rotation issues but either way, i highly doubt this works at all

it left artifacts in roughly the exact same places

you can ignore the dust motes on the left image because they are new

although I think the issue is manifesting due to light pollution and these light frames are already tainted

i would have to get new light frames to verify

[tight lodge]

Are we the only ones in this server that actually work on getting an optically perfect telescope?

[frosty shard]

yeah because mine is optically perfect as-is.

[harsh matrix]

Actually I can see that Hotspot by shining my phone down to the primary mirror

[frosty shard]

oh sorry you were asking if we were the only ones, not just you, I misread

[tight lodge]

Yes... we. Not me. WE

[harsh matrix]

@tight lodge you use Fusion right?

[tight lodge]

Yes sir

[harsh matrix]

can you make threads of finer pitch than 1.5 mm?

[tight lodge]

Yes, but you might not be able to 3D print them😅

[harsh matrix]

I've been able to 3D print a pitch of 1.0 i believe

I need 0.75 mm though

@frosty shard I guess I am not making it threaded

maybe i can press fit it in idk

[tight lodge]

In fusion360 you have a thread function. You select the body, then the metric and the pitch

[harsh matrix]

Thats what I was doing

But afaik, it locks you into the choices in the drop down

[tight lodge]

Yes, that's because of the diameter of the part. It tries to match the metric and pitch to standard dies that you can find. Ok... an m48x0.75 die will cost you a kidney

[harsh matrix]

bruh

that's okay

backup plan

💀

we'll just press fit it in like this

the outer diameter will be too large to fit in the front of the reducer but with these gaps, the plastic can deform enough to fit

in theory

[tight lodge]

Make a quote at JLCCNC and see how much they ask for

[harsh matrix]

No

Not worth it

[tight lodge]

Not worth asking?🫠

[harsh matrix]

Nope

[tight lodge]

What if it's a good deal?

[harsh matrix]

dont care

dont need to pay for something this simple

[tight lodge]

So what do you need it for?

Duuude!

I think I got something

Are the edges of the lenses inside the reducer painted black?

[harsh matrix]

The reducer

[harsh matrix]

I dont think so

[tight lodge]

It could be glare from the lens edge

[high aspen]

:D

[harsh matrix]

I am going to give the reducer one more try tomorrow night

If it fails, I will not use it again, or at least until I am done holding a grudge.

[tight lodge]

If it fails, take it apart and use a sharpie to paint the lens edges black

[tall summit]

@digital nexus curious, how is the collimation looking, did you have a chance to test?

[digital nexus]

nope

I won’t be able to until this weekend

I’m back in my dorm for the last week of university

[harsh matrix]

My 585MM Pro is here

[tight lodge]

When we expecting the first light?

[harsh matrix]

I wanted to do it next week

Buuuuut

I think I may do it tonight.

There's no reason not to.

[tight lodge]

What ya shooting?

[harsh matrix]

I haven't picked yet

[tight lodge]

something easy to shoot maybe?

[harsh matrix]

Probably

It would have to be narrowband too since the moon is full

[harsh matrix]

question mark nebula?

lemme look around first

[tight lodge]

Check the framing😂

I can't fit the thing in my framing

[harsh matrix]

i fit the fun parts in

[tight lodge]

How about the Tadpole?

[harsh matrix]

that was next on my list

[harsh matrix]

revised

[tight lodge]

Did you just gently moved a bit to the left?

[harsh matrix]

yes

to get the cluster lmao

Flaming star would be cool too

[tight lodge]

Cone nebula?

I get a decent framing on it at 650mm

[harsh matrix]

this is hot tbh

😩

[tight lodge]

I'd go for this one. Just dump a whole night of Hα

[harsh matrix]

i dont have a horizon on it though

the longest i can shoot it in one night is 4 to 5 hours

basically as it goes straight overhead

[tight lodge]

But... alnitak😭

[harsh matrix]

alnitak can suck it

idc

cone neb might not be terribly painful with the quatt

since the quatt is f/3.45 or some bs

oh yeah the 585 has goated QE in H-alpha too

hmmmmm

maybe it wont be so bad

[tight lodge]

[harsh matrix]

i think the 585 has better QE than my other 2 cameras

in general

i wish it didnt have such a small fov

and i wish the pixels were bigger

but that's the greedy RC8 user in me

it pairs well with the quattro

[tight lodge]

you should actually get good sampling with the quattro

[harsh matrix]

yup

i am really not in love with undersampling atm

it's atrocious on the redcat

[tight lodge]

square stars?

@high aspen can you simulate a 10" 650mm f2.6 RCT in your fancy software?

[harsh matrix]

worse than that tbh

pixel sized stars

or 2 pixel sized stars

[tight lodge]

please show me

[harsh matrix]

almost so sharp that they look like noise

[high aspen]

if u want

[tight lodge]

i'm just curious to how good or how bad it would be

[harsh matrix]

[tight lodge]

LMAO

[harsh matrix]

that's the only downside to this scope getting fixed

[high aspen]

the field flatness will be not im pretty sure

[harsh matrix]

the sampling is worse

[high aspen]

but ill do a sim

[harsh matrix]

[tight lodge]

ok, the bright stars are fine. but damn the small ones are literally minecraft stars XD

[harsh matrix]

yes

[high aspen]

ewwwe

i could never

[harsh matrix]

😭

[high aspen]

mc dirt texture

i think you have to drizzle now

[tight lodge]

[harsh matrix]

fr

thats what comes to mind 😭

[tight lodge]

tysm

[frosty shard]

Me here waiting for an APS-C Starvis 2 sensor

[tight lodge]

everyone here is waiting for one

[tight lodge]

ooooor we shouldn't

[frosty shard]

That's not Starvis 2

[tight lodge]

oh... i misread that

[tight lodge]

Any starvis is better than no starvis😂

[frosty shard]

Starvis 2 only exists for mass surveillance applications unfortunately

I wouldn't be surprised if we're stuck waiting for longer

[tight lodge]

And dash cams

[harsh matrix]

Real

[high aspen]

i tried....

this is the best i can do

[high aspen]

@frosty shard https://www.firstlightoptics.com/starbase-telescopes/jscope-80-l-80mm-f15-refractor.html

its an actually decent frac

they are made per order

and are high quality

and they f15

so they loooong

https://www.firstlightoptics.com/starbase-telescopes/jscope-80-s-80mm-f7-refractor.html

mini one

probably the only frac i would ever buy

[harsh matrix]

@tight lodge

[high aspen]

cyck foccuussee!!

how is it??

[harsh matrix]

Rock solid

[high aspen]

woa

how much it cost again?

[harsh matrix]

I think it was 200 USD or something but I didnt buy it for this scope

[high aspen]

ah oker

[frosty shard]

2long4me

[harsh matrix]

@tight lodge 10 minute H-alpha sub with the 585 mono on the quatt

waiting for cone to rise atm

[oblique sun]

your one sub is almost as good as my stack

and you are in slightly higher light pollution than i am too i think

damn mono nb is too good

[tight lodge]

Prime example of IMX585M in action

[oblique sun]

I want one but it feels like a waste getting the mono version of a sensor i already have, even if it isnt

and the next sensor I'd want is way too expensive (571)

[tight lodge]

Get it

[oblique sun]

Also i can never make myself spend money

and a new mount is first priority

im using an eqm35 rn

with a 6" newt

[tight lodge]

Aaahhhhh

Get a bigger mount then

[oblique sun]

i want a ragdoll17 but again i can never make myself spend money

im too stingy

i have the money for both but i can't make myself buy either

[oblique sun]

Idk if stingy is the right word, you get what I mean

[tight lodge]

Close your eyes and click buy

[oblique sun]

also parents issue

[harsh matrix]

Yall should see the linear version lmao

https://cdn.discordapp.com/attachments/975845011260309587/1445616815894958150/image.png?ex=6930ff13&is=692fad93&hm=8c4eea9c2f113c5928996049c26c0f144e321ac9321d8be8f647055f01591b8e&

[tight lodge]

You got more nebulosity in linear state than what most people get in couple of hours stretched

[harsh matrix]

Yeah 😭

[tight lodge]

Wait. You got the AM5N and EQ6R. Double setup per night?

[harsh matrix]

Did you just realize that?

[tight lodge]

I'm happy that you can finally use them both at the same time

[harsh matrix]

same

though 'use' is a little bit of a loose term at the moment

https://cdn.discordapp.com/attachments/975845011260309587/1445665904724676648/image.png?ex=69312cca&is=692fdb4a&hm=cd0611af70297eef99aa73945bf4a830ecb690968bf37a18e4a277d877eb3171&

@frosty shard I made a meaningful change to the reflection

Buuuuut as you can see

The issue remains

[frosty shard]

Big oof

Man I didn't realize how much I was cooking by not using a reducer

[harsh matrix]

No kidding

Im so unhappy rn

We are ditching this thing for the rest of tonight

Id like to see what lum is like without a reducer

[high aspen]

thats why its so great!!

its stupidly long

and its prefect!!!

[tight lodge]

Why?

[harsh matrix]

Because I am troubleshooting the RC rn

The Quattro and AM5N are being used

This rig is not so much

[tight lodge]

Ahhhh. Well atleast you have a backup

[harsh matrix]

That and the nice thing about having 2 rigs is it gives me the ability to troubleshoot frustrating issues like these reflections.

Rn the inside of the entire optical path is a black hole

It is where stray light dies

[tight lodge]

Speaking of backup
Mine is taking shape

@harsh matrix What if you put the reducer from the Quattro on the RCT?

[harsh matrix]

Because the quattro has a coma corrector and not a reducer.

[tight lodge]

So your quattro is not reduced like every Q150P?

[harsh matrix]

It is reduced but a coma corrector that reduces is not the same thing as a reducer

[frosty shard]

That's why I can't wait to get another mount or even OTA...I can use one for visual and one for imaging...or perhaps both for imaging

[harsh matrix]

Just like a reducer is not the same thing as a field flattener

The reducer for my RC8 is a reducer/flattener and the reduction isnt the same as the quattro CC

[frosty shard]

You'd get reverse coma if you used a coma corrector on an RC

I mean technically you could use a coma corrector on an RC, but it would have to very specifically null the 5th order term since the 3rd order term is nulled

Also, @harsh matrix have you seen this?
https://www.astrosysteme.com/wp-content/uploads/2020/11/asa-comparison-rc-against-cdk.pdf

The interesting part isn't comparing the DK to the RC or the CDK to the corrected RC

Look at the on-axis spot size when you compare the RC to the corrected RC

It's worse if you add a corrector! Which lines up with your sharpness observation

[harsh matrix]

NO SHOT

[frosty shard]

If the corrector doesn't have aspheric surfaces, there's probably a bit of induced 6th order spherical aberration

[harsh matrix]

I AM BIG BRAIN?

[frosty shard]

I also suspected this myself (especially for IR) so that's why I never used mine

[harsh matrix]

Oh my god

You're right

Well I was right and you're right that I was right

I knew it

Reducing an RC is a psyop to get us to shoot lower quality images

[high aspen]

rc's and cc's dont benefit from correctors

[tight lodge]

Naaah. I'll just stick with newtonians. Less pain in the arse

[frosty shard]

The difference is actually pretty small, but since the PSFs convolve, you will be able to notice a larger spot size

[frosty shard]

You can use a coma corrector on a classical Cassegrain

[high aspen]

it still degrades image quality

on axis a perfect cc has less than 1um spot size

[frosty shard]

Would Zemax let you solve for an aspheric corrector? You could design one that has no on-axis aberrations in principle

[high aspen]

maybe

i still need to learn the optomiser

its got like 100 different settings

[frosty shard]

@high aspen also if you notice, at 16 mm away from the center (which is beyond the vertical margin of a full-frame sensor) the spot sizes are basically the same, so there really isn't that much of a point of a corrector like this for APS-C or smaller

Even at full frame the benefit is marginal

[high aspen]

ya

i knows

[frosty shard]

I will take my CA free infrared channel :D

[harsh matrix]

5 minute Ha sub at native on the RC

[high aspen]

[harsh matrix]

[high aspen]

sharp

[harsh matrix]

right?

[frosty shard]

Whatcha shooting

[harsh matrix]

for 1628 mm

quite good

[harsh matrix]

Tadpoles

for now

gonna swap to a broadband target later to test luminance

[high aspen]

that was like my 3rd ever target!!

[harsh matrix]

ive yet to give it a fair shake outside of the last 2 weeks with my redcat

[harsh matrix]

but the cat is wider than i want to go on them

[high aspen]

cart

[harsh matrix]

i want to see them up close

[frosty shard]

I am debating what to shoot tomorrow...it looks clear but windy

[high aspen]

ya

[high aspen]

my first try on this data was not good 😭

[frosty shard]

Ugh, the moon looks to be too close to the California Nebula

[high aspen]

:(

i haet the mooon

[frosty shard]

I guess I could continue on the Heart Nebula

Maybe get IR stars?

H-alpha if I can manage to continue with 4 minute exposures

[harsh matrix]

I am going to do lum testing on M108

something not imaged often

this guy is tiny

[frosty shard]

Oh shoot the moon occults the Pleiades tomorrow night for me

[tight lodge]

I never shot it😭

[harsh matrix]

2.5" FWHM

despite the seeing supposedly being in the 3 to 5" range tonight according to the forecast

see?

I do have the seeing cheats

the RC8 is averaging 0.42" RMS atm

not the best ive ever seen but for this part of the sky, it is exceeding expectations

[frosty shard]

I need to fix the brightness but

[harsh matrix]

alright i am going to do a test stack of my bub neb data

no flats

no calibration frames

just the raw lights

(havent taken calibration frames with this cam yet lol)

[harsh matrix]

please do

one of us has to

i dont think my skies will permit though

[frosty shard]

wait to be clear that is my image, I just used the new Stellarium plugin to add my image

The original is worse in quality

[harsh matrix]

what the hell

[frosty shard]

Add/enable the Nebula Textures plugin

Then you can add your own images to Stellarium

You will probably want to clip the blacks it seems

I need to reprocess that anyway

(You probably also want to update Stellarium if it's not available)

[harsh matrix]

my quattro is getting some of the most beautiful data ive ever laid eyes on 😩

[harsh matrix]

ewwwww

the images built into stellarium arent exactly black clipped either tbh

you could use the DSS colored sky survey instead of the default sky which is what ive been doing

[frosty shard]

You're right

[harsh matrix]

[frosty shard]

IC 10 should be pretty faint regardless due to extinction

[tight lodge]

You only need flats and bias with it

[harsh matrix]

ik

point is that ive not taken either of those yet

[frosty shard]

(psst...darks do help if you want to make a hot pixel map)

[harsh matrix]

ofc

i have no need of that though

not atm anyway

not bad

3 hours of 10 minute subs

i expected no flats to go worse tbh

[tight lodge]

EZ data eh?

[harsh matrix]

very

i bet the noise will vanish after applying flats

[tight lodge]

How much time so far?

[harsh matrix]

2 hrs 50 mins

the nebulosity and some of those clustered stars threw it off

still not bad

[tight lodge]

I mean, it looks quite clear for that much

Says the guy who averages 2h per set💀

[harsh matrix]

that's the power of the quattro

[tight lodge]

How long are the subs?

[harsh matrix]

10 minutes

I really want to take this thing to those bortle 3 skies now

[tight lodge]

As they should be

[harsh matrix]

i just realized i needed to purge some of these subs and forgot

it started to venture through my tree

had to delete another because of a plane

okay maybe the noise wont be gone after flats

[tight lodge]

I feel that pain. I had to throw 70min of data when I shot the fish head😭

[harsh matrix]

2.91" FWHM

hey

it's sharper than my RC6

[tight lodge]

And you know why? Some moron @tight lodge , forgot to enable refocus after HFR increase

[harsh matrix]

bro 😭

[tight lodge]

Yeah. Aaand because my spider is flocked I didn't noticed the quad spikes until I had to really zoom in on them stars

[tight lodge]

2.1 is the target

1.9" was the lowest I ever got with mine

[harsh matrix]

hecker

i havent imaged around this 1" scale in forever

this is fun

[tight lodge]

You're sampled at 1" exactly?

[harsh matrix]

nah

1.167"/px

i was at 1.09"/px last time i owned a ZWO cam

1.36"/px when i imaged reduced with that came and scope combo

im technically smushed inbetween both scales of that particular rig

with 2" more of aperture

wtf is all this stuff

i dropped the exposure time down to 5 minutes btw

since it was clipping the bright parts of bubble

didnt want the same thing to happen in the cone neb

@tight lodge here you asked for it

now you get it

😩

it has the hubble floofiness

pretty cluster imo

holy

this isnt blurX'd

btw

[tight lodge]

That's a very bad context to put it. That thing looks rather phallic

[harsh matrix]

💀

okay id own up to it if i meant to make that joke

but i didnt mean it

bro

should i

try

HaRGB on it?

and also do a HOO or SHO version?

im going to test how long exactly i can shoot it for tonight

then plan accordingly

[tight lodge]

If you got the time, go for it. You payed for all the filters, use all the filters😂

[harsh matrix]

yooooo

now we're talking

im surprised the quattro is guiding at all

these stars are actual worms

[tight lodge]

Damn... that CC is struggling at the edge

[harsh matrix]

yes

very much so

btw that's not even at the edge of a 2" frame

that's at the edge of a 1.25" filter

and it's a 120MM Mini of all things

tiny sensor

should not be this bad

this CC is pretty not good

[tight lodge]

Not at all😭

[harsh matrix]

the corners on the 585 arent all the brilliant either

dang it man

i want flats

less sharp than bub apparently

[tight lodge]

They look about the same as mine after not colimating the telescope for the past 4 months

[harsh matrix]

i havent collimated this since august

but i never did get them 100%

the corners

i suspect it's the CC

light pollution is not playing nice with this poor galaxy

💀

[tight lodge]

Did yours also spent that time on the back set of your daily driver? 🤣

I think mine holds colimation pretty well ngl

[harsh matrix]

no but it did sit in my closet for most of that time

[harsh matrix]

mine isnt doing half bad either tbh

[tight lodge]

Ok then how is it possible that ours stay colimated and everyone's else don't?

User error but blame the gear😂 😂

[harsh matrix]

could genuinely be

moving the scope around too much can cause it to lose collimation

but that has only happened with my RC

my Quatt seems to stick for whatever reason

ugh the EQ6R wasnt guiding well

turns out my PEC turned itself off when i had to task manager EQMOD

[tight lodge]

Ok... if EQMOD crashes. You are done. The only way to fix it is to completely restart the PC. It happened to me once. Everything seemed to work fine. The mount was slewing to the target, plate solve and so on. But PEC and guiding pulses were not doing anything

[harsh matrix]

guiding works

im letting the PEC seek atm, if it cant find its place, then im not going to worry about it

i dont need amazing data tonight from this scope

i need just enough to test flats with

i got it to play again

had to turn the gain up to 1

[harsh matrix]

i want flat frames for breakfast

[tight lodge]

The flats are working?

[tight lodge]

Discord reply works amazing 💀

[harsh matrix]

true

[harsh matrix]

didnt try any yet

[tight lodge]

Damn they sharp

[tight lodge]

Oooooohhh... because you take them in the morning. I get it

My brain is awfully slow for some reason

[harsh matrix]

no

they did not work

[tight lodge]

Subtle... but I do see some repeating rings

[harsh matrix]

i took lum frames before i got going

[harsh matrix]

yes

i dont know what's causing these

you can see it in the master flat too

DBE flat

this is getting left over

looks like a light leak to an extent

i couldnt see something this subtle in the flats and broadband lights i took for the fish head project because of the nebulosity

thats why im testing out in open space

[tight lodge]

Hmmmmm dumb hypothesis.
The baffles.

I hope you understand the idea😂

[harsh matrix]

im kind of thinking them too

[harsh matrix]

nah not like that

the camera can only see the secondary mirror

nothing else

not even at extreme angles

[tight lodge]

I know, I exadurated the drawing. But it could be that the bottom side of the baffles are iluminated juuust enough to scatter some light and make it into the camera

[harsh matrix]

https://stargazerslounge.com/topic/392748-help-flats-causing-circular-concentric-rings/

[harsh matrix]

that would be hardly suprising

[tight lodge]

This is what looking down into my OTA feels like. Hard cut edge where there's light and then pitch black. Everything is flocked😂

[harsh matrix]

same deal as my quattro

the RC has knife edge baffles and i just resecured them

they cant move at all

so i dont know why they would have anything to do with this

[harsh matrix]

this is useless nvm

[tight lodge]

How about the secondary mirror baffle?

[tight lodge]

That was a waste of time to read💀

[harsh matrix]

i think it might be the focuser drawtube

💀

[harsh matrix]

yeah

[tight lodge]

The interior is not flocked?

[harsh matrix]

pixinsight already saves everything as 32 bit

[harsh matrix]

it's matte black paint and not reflective but the "black" is more like dark grey

[tight lodge]

Ok... I can help you find something better to flock the draw tube

[harsh matrix]

yeah sure why not

i can order something

it would be worth my time to flock more than that too

like the inside of the focuser housing, outside and around the drawtube

[tight lodge]

Electric harness tape

It's made of fabric and it's quite good at absorbing light

You can see my drawtube here

[harsh matrix]

is it a roll sort of like this?

seems like this would be a nightmare to install

[tight lodge]

A bit annoying. Since that thing only sticks once

[harsh matrix]

I can order thin sheets of traditional flocking material

I could measure the inner circumference of the drawtube and cut it to the right wide and length.

Same goes for all of the extension tubes and the inside of the focuser housing if I want to

[tight lodge]

Or that

[digital nexus]

hey RC people

Who uses an OAG

Can I use a 120mm with an OAG?

[tight lodge]

What?

You want to use an OAG with this?

[digital nexus]

What

no

asi120mm guide camera with an OAG

[tight lodge]

Ahhhh

[digital nexus]

What am I even looking at here

[tight lodge]

120mm means 120 millimeters

[digital nexus]

it also means 120 mono sensor

[tight lodge]

Some Svboner guidescope

[tight lodge]

Yeah, on e complete context😅

[digital nexus]

I’m getting an OAG for free on Saturday, and the same guy is selling me an asi120mm for $100

Because my imx290 SVBONY cam is absolutely garbage

And barely works for guiding

So I can’t use it :/

[tight lodge]

But yes, you can use the asi120mm with an OAG. is it the lipstick one?

[silver ibex]

WTF IS A MILE 🗺️

[digital nexus]

but I’m hearing it may be too small of a sensor

Yea it’s lipstick probably

[tight lodge]

About this much

[digital nexus]

all I know is that it’s the asi120mm

[tight lodge]

This?

[digital nexus]

That’s what I think it is

I haven’t seen any photos or anything

[digital nexus]

Yea it’s the lipstick just asked

But if im using it as an OAG with 1377mm FL isn’t that a lot for that small sensor

He says it worked with his OAG

[tight lodge]

Your guiding might be very oversampled at that focal length

[digital nexus]

He just told me he used it at 1480mm FL, and it was fine. He only had issues at 4800mm

[tight lodge]

Asi120mm is a bit old. I'd rather go for PlayerOne Ceres 462M or Sedna

[digital nexus]

Im broke

im paying $100 for it

[tight lodge]

Ahhhh

[digital nexus]

Idk if you’ve seen but my current guide cam is just dying. So I need something to replace it

I can always get a different guide cam for the OAG later, and use this one for my Askar guide scope

I want to eventually work my way to having 2 rigs

That’s my long term goal

[tight lodge]

Any guiding us better than no guiding

[high aspen]

any salmon is better than no salmon

[tight lodge]

i don't like salmon

[high aspen]

not even smoked??? 😰

[tight lodge]

Especially smoked

it tastes like eating a wet ashtray 🫠

[high aspen]

howww 😭

ive tasted a wet ashtray and it tastes nothing like that :(