Ritchey–Chrétien enjoyers thread

[desert locust]

but dont delete any subs yet

I need to do some sub diagnosing

see how the target looks n stuff

[high aspen]

theres nothing visible in the singles

[desert locust]

send me a few or a stack when you can then

[high aspen]

23 mins of data

tf is the magnitude

you can see how it got occluded

i am now do unoptomised stack

[desert locust]

thanks

[high aspen]

sharper in proper stack

[desert locust]

its a little dim

hpw much int?

[high aspen]

23mins

[desert locust]

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

[high aspen]

i am now do unoptomised stack

[desert locust]

whats optimized stack mean

[high aspen]

does everything to try correct stuff

its actually the opposite its like half an hour sliwer

[quartz meadow]

just a tad

[tulip iris]

Ay guys im shooting m51 rn and ill do 4hrs, after that in post processing should i hardware bin if my resolution rc6 combined w 533 is um idk 0,56”?

[high aspen]

6" or 8"? (pretend i didnt ask this pls)

if you can pull off the subs dont bin (theres also a smoll chance you resolve something cool)

if you cant pull off the subs do

oversampling > undersampling

[tulip iris]

Rc6

[high aspen]

i realised after

[tulip iris]

I actually never binned before but idk just came thru my mind

[high aspen]

i only bin if my seeing dont support it

otherwise i leave it

[tulip iris]

Idk sincerely if my seeing supports it or not

[high aspen]

it will be okay dont worry about it

[tulip iris]

I have no idea abt the seeing atp if meteoblue aint reliable

[high aspen]

all i can say, if it works it works

(about your imaging)

[tulip iris]

Mhmmmm sometimes i feel like the image is okay but something is missing

[tulip iris]

Alright

[high aspen]

usually int time for me

[tulip iris]

Well since even tracking is seeing based stuff seems okay atm

[high aspen]

comdet but 12 mins

[high aspen]

[tulip iris]

Whats this

[high aspen]

i cant remeber

@scenic mango what was it

[tulip iris]

Its all trailing around

Aint it a comet?

[scenic mango]

24p

yes comet 24p

[tulip iris]

Okay

Thought so

[scenic mango]

lol

[high aspen]

bobbbb

[scenic mango]

yo

[high aspen]

what eould happen if i subtract the comet from the comet on a different day

will i be able to see the progression of the comet

[scenic mango]

i can sleep at night now

[scenic mango]

yes

[high aspen]

wh

[high aspen]

do you want the raw

i can send u the raw

[scenic mango]

nah

[high aspen]

awh

i wonder if its bright enough to galaxy subtract it yet

[scenic mango]

this is the brightest it'l get

[high aspen]

darn

[scenic mango]

it actually is a mag fainter than it was at best

[high aspen]

i wish i got it when i could have started now

i coulda got an hour on it

[scenic mango]

you want some of my data?

[high aspen]

combine data?!

[scenic mango]

proly not combine

[high aspen]

oh yea

different days

i would be able to subtract it tho!!

wait no

it moves

i wont be able to align the inages

[frosty shard]

Babby's first continuum subtraction

[harsh matrix]

first test of the RC with new knife edge baffles put in the baffle tube is happening as we speak

unfortunately collimation isn't great so ill have to revisit that later this week if possible

okay "not great" by my standards

it's probably acceptable to most people

[tight lodge]

As long as there are no funky reflections, its totally fine

[frosty shard]

I overcooked it the first time, this looks better IMO

[high aspen]

pibk

[frosty shard]

strawbee

[high aspen]

yummyyy

[harsh matrix]

baffles made it worse

a lot worse

[slate falcon]

hai

[slate falcon]

at least the data looks cool

[harsh matrix]

Not really

It's pretty awful

[slate falcon]

i think i can see ur secondaries shadow btw

[harsh matrix]

Idk what that means as far as whatever is happening with the scope.

I think what we're most likely seeing are the spots where light isn't reaching though

Those dark spots

Or theyre over corrections.

https://cdn.discordapp.com/attachments/1361158206461837433/1473238995163938949/image.png?ex=6998c7fb&is=6997767b&hm=8bda2764c954935b0a1a7cf7cf700e6c6498dd24d00b65c18dd3c711b35f1217&

This is what the flat is like after ABE

We're more or less seeing an inversion of this in the light

Also idk wtf is going on with the dust motes.

Why they are corrected in a line through the middle but left uncorrected at the top and bottom edges.

That makes 0 sense.

No motes from the filter either.

Very very strange.

Im having a hard time understanding what I see.

This is an outdated and imperfect representation of what the camera sees.

The front most knife edge baffle is farther up the tube but you can still see the inside of the baffle tube extension.

[slate falcon]

i meant the giant dark spot in the middle

that lloks like a shadow

[harsh matrix]

Unlikely

It's extremely bright there in the flats

[harsh matrix]

Most likely an over correction from flats.

[slate falcon]

it is yea

[slate falcon]

prolly

[harsh matrix]

This is what we are looking at

If you think about it, this should be matching the flats

But it does not

What is producing that bright spot in the flats and why isnt it visible here?

[slate falcon]

maybe light reflecting off filter than back into it?

[harsh matrix]

That's my biggest concern.

[harsh matrix]

No I think it's more complicated than that.

[slate falcon]

i would think so

it looks like something is causing the light to focus in the center

[harsh matrix]

Yes

[slate falcon]

well thats kinda what is happening afaik

[harsh matrix]

That's my suspicion as well

Here's the real kicker

[slate falcon]

do you have a reducer on the scope?

[harsh matrix]

I dont have an example on hand rn

[harsh matrix]

Yes

[slate falcon]

reducers cause light to focus usualy

[harsh matrix]

But originally, flats with this camera and reducer produced a dark spot in the center with a bright ring around it.

[slate falcon]

whaa

[harsh matrix]

Yup

[slate falcon]

whats caused it to invert?!

[harsh matrix]

That's signature of bad baffling.

[harsh matrix]

The addition of the knife edge baffles.

But why?

[slate falcon]

a

[harsh matrix]

I have no idea.

These baffles dont intercept the light path whatsoever.

They dont intrude even slightly.

That's why i didnt slide them all the way up the tube just yet

[slate falcon]

i think i see a slifht reflection off of it

[harsh matrix]

This same thing happened last time I tried this.

[harsh matrix]

You do but that was before I painted it.

You cant see it anymore now.

[slate falcon]

that makes sense

[harsh matrix]

I wanted to see if by not blocking visibility to the inside of the tube, from the center of the sensor, if this problem would return.

It has.

Im going to slide the baffles farther up when I get off work and test that.

If it gets worse then ill slide them the other direction but by how much, I dont know.

I need to figure out this behavior before I can design a solution.

[slate falcon]

what if it causes both to happen at the same time

the outer bright ring and a spot in the center

that would be baffling

[harsh matrix]

It had already been doing that.

So I wouldnt really be surprised.

[slate falcon]

ye

[slate falcon]

it kinda looks like a flat psf of a point source from a bad scope

also can i see the spider in that

i was in fact tripping

are you off collimation?

if you are i wonder if thats contributing a bit

[harsh matrix]

Yes

Quite a bit off for my standards

Im wondering if that is contributing as well

Historically it has made no difference though.

Ive noticed the same behavior with my quattro

Collimated vs not collimated has no bearing on how well calibration works.

[harsh matrix]

@high aspen this is what i think the issue is

Or @slate falcon

You see the ghostly donut thing in the first image?

Pretty sure that's a reflection of the secondary on the reducer.

Im concerned that may be what's causing the bright spot.

The bright silver rings are my phone lenses

[harsh matrix]

Okay i have the baffles to a point where they dont let any stray light in or scatter to the camera.

One problem.

The primary retainer ring is now my biggest enemy.

Stray light that bypasses the baffles doesnt terminate when it hits that.

Instead it scatters and all of it ends up all over the camera sensor.

I will see if flocking does anything

[harsh matrix]

More importantly: I can still use the whole primary mirror.

According to a laser test anyway.

[tight lodge]

That shouldn't be visible

[harsh matrix]

That's the edge of my phone's lens

[tight lodge]

Aaah

[harsh matrix]

Alright if this dont work I will be mildly upset

I decided to flock the primary retaining ring again because it has better oblique angle scattering/absorbing characteristics than the paint does.

[harsh matrix]

Im so nervous rn ngl

If theres any more reflections, I can still flock the reducer a little.

[silver ibex]

Why do you have so many issues with the scopes 😭

I don't understand if you just got really unlucky or if your standards are higher

[harsh matrix]

Bortle 8/9

Nothing works as intended in these skies.

@tight lodge new flats look fantastic

The only concern left is how they calibrate lights and how lights are affected by the scope itself.

Fingers crossed...

[harsh matrix]

look

this looks a but funky

not sure it will be a problem though

i need to deep clean this imaging train now

jesus

new vs old

moving the top most knife edge baffle farther up expanded the bright point of illumination

smoothed out the dark ring

the light ring no longer has any harsh edges either

collimation could have been why the dust didnt calibrate out though

you can see in the flat from yesterday that the bright point is offset by quite a bit

the new flat has it centered

cause i did a janky bench collimation

[slate falcon]

[harsh matrix]

ugh this still isnt any good

dust motes survived calibration too

im betting if i flock the rear of the apex, it would help a lot

that's the only place left that can cause weirdness like this

cant believe i didnt think of that earlier

[slate falcon]

i think the easiest solution is to move

[harsh matrix]

real

I do think if I get this thing fully sorted out, id still get the nuttiest dark sky data known to man.

Even better than what ive gotten before.

I really think these remaining issues may be entirely down to the apex as ive got the scope as sorted out as I can possibly make it.

That ghost image in the middle seems to be what I took a photo of earlier today.

I'm not sure what to do about that since theres not really anything I can do.

[tight lodge]

I think, you might need a sensor cleanup

Iirc, you said those dust motes are o the sensor itself

[stiff mason]

Gang how are you still struggling

[slate falcon]

my flats for comparrison 😭

(you can see the vinyette at the top)

its my 850nm flats

[tight lodge]

@harsh matrix These are the flats from the cone nebula🫠

[slate falcon]

these were dark sky flats

and worked really well actually

[stiff mason]

Like i thought you would have fixed it by now

[harsh matrix]

Looks bad

[tight lodge]

[harsh matrix]

because this scope refuses to cooperate

it defies all logic atp

there's no reason to see the problems that I do, yet I see them

it's unbelievable that the stack still looks like it garbled up a bunch of stray light even though stray light is unable to make it to the camera or scatter to the camera.

[stiff mason]

The light from stars can still scatter

It doesnt have to a street light

[stiff mason]

Also this looks pretty reflective

[desert locust]

Does a dirty mirror or a shiny/sparkly baffle or flocked surface cause star scattering

[harsh matrix]

this part is not

but

[stiff mason]

That baffle will probably be an issue but the mirror and flock surface no

[harsh matrix]

the part you are concerned about is also on my radar now

even though that part cant get catch stray light either, it looks like it is funneling the light column down to the camera in an over powering manner

that's all the reducer now

[stiff mason]

Maybe your mirror is warped or sum

But that would show up in your stars

Still could be an issue

[desert locust]

Could it have something to do with reflections off a filter

[stiff mason]

Maybe you could try a different mirror if you have one

[harsh matrix]

dont know but i dont think the filter should be the concern here

i think the reducer itself is what you need to be worried about

look at this ghostly eyeball looking thing being reflected to the secondary

pretty sure this is some kind of image that is being produced and reflected up to the secondary by the reducer

how do I know?

because I've seen this very similar image in the center of the reducer, just a little bigger, by looking through the front of the scope.

which unfortunately if this is causing issues, and I manage to fix every other suspicious problem with the Apex, and this still remains, there's nothing i can do about it

it appears to be produced only by the glass itself.

[harsh matrix]

yes

need to clean the lum filter too

the whole thing needs to be deep cleaned

i fully assembled it in May or June of last year, cleaned it by dust blower only ever since, not good enough for the stuff that falls and gets stuck

if i nuke all of the dust, then this dust issue probably wont be an issue until i see new motes

even then, it might be fine as long as i flock this reducer

[tight lodge]

I gotta do the same. i got those 3 dust motes across all the filters and they annoy me. i mean they corect fine, but... it's better when they are not there

[frosty shard]

Ghost pupils are a common enough issue on professional RCs with flatteners/reducers that I've seen documents mentioning the issue

[frosty shard]

and yeah I need to clean my filters and sensor...

https://www.cloudynights.com/forums/topic/375458-the-sct-f63-focal-reducers-pupil-ghost/

[harsh matrix]

dafuq

does it affect images or is it a red herring?

[frosty shard]

It does affect images and you need to subtract its contribution from the flat frame

The ghost pupil adds extra light to the frame

[harsh matrix]

yeaaaaaaahhhh

i think that's my issue

but how do you account for it on its own?

[frosty shard]

It doesn't really affect lights, just flats, so if you can model the difference between the ideal vignetting profile and the ghost pupil, it should be correctable?

[harsh matrix]

I dunno what the characteristics of the pupil are

💀

[frosty shard]

I think you can model the ideal behavior with a cos⁴ law, and treat the exit pupil as an addition to this law

[harsh matrix]

[harsh matrix]

Does it only contribute brightness or can it contribute structure as well?

[frosty shard]

Oh, the excess brightness is just the ghost pupil

The goal is to find the additional light from the ghost pupil and subtract it from your already existing flats

[harsh matrix]

Ahhh

Wouldn't that mean the flats always over subtract?

[slate falcon]

only in the areas it needs to probs

[harsh matrix]

Well no the flats would be over subtracting due to the additional light from the ghost pupil.

[slate falcon]

thats why you subtract it

also my flats have a lil vignette 😭

[tulip iris]

@harsh matrix I noticed my rc6 doesnt really have its dust motes corrected aswell lmao, what a weird thing

Maybe happens cuz those dust pieces are like, more pronunced?

Dunno ngl

[harsh matrix]

I think the more pronounced ones show up earliest but I think all of them will show up with enough integration time.

[harsh matrix]

@tight lodge I opened up the filter wheel and cleaned the camera sensor and lum filter

I found the lum filter glass was LOOSE inside of the mount.

Not sure if I loosened it while cleaning it or if it's been like that since I got it or happened recently, I have no idea, but I do know it was loose at some point when I was cleaning it.

What if this is the cause of the dust not calibrating...

It was loose enough that the only reason I noticed is because it was making a clicking sound and it felt like the glass was moving.

[harsh matrix]

i flocked the rear of the starizona too

looks clean at first glance

still kind of the same story

and this is why i dont clean things

no matter how hard you try

no matter how much time you waste

it stays just as dirty or gets worse.

some weird af tilt shift happened

blink between the 2

collimation has not moved, camera rotation is within 2 degrees afaik and the reducer is in the same position afaik

huuuuhhh?

I think my double illumination theory was right

but for the wrong reasons

was the lum filter loose THIS ENTIRE TIME?

EVEN THE LITTLE MOTE ON THE PIXELS MOVED

WHAT?

I think it has been loose in the mount for MONTHS

there's no other explanation

that would explain why i started seeing this exact problem on the quattro too

[tight lodge]

What would technically explain why it was difficult to correct

[harsh matrix]

extremely difficult

it would explain why suddenly the motes came back after they were fixed with the 533 as well

however i think it was still an issue and may still be

i can see motes in my RGB from the same night i did the crowbar test

i did photograph the bottom of clouds to test rq

no motes survived calibration despite being very visible in the stack

[frosty shard]

I'm gonna take a moment to check all of my filters...

[tight lodge]

Sir, I see squares

[harsh matrix]

that's heavily denoised and not bias subtracted lol

[tight lodge]

Interesting to see that the denoise algorithms tile the image

[desert locust]

[harsh matrix]

nah the filter has nothing to do with the ghost pupil

that's what that conversation was about

[desert locust]

What’s a ghost pupil

[harsh matrix]

this thing

kind of looks like an eyeball

it's essentially a reflection of everything that's visible on the secondary being bounced back up at the secondary by the reducer

[tight lodge]

Damn... super nuked and is flat?

[tight lodge]

So, my hypothesis from a very long time ago was right

[quartz meadow]

I feel like Veloren has been struck by a curse

[tight lodge]

High bortle sky curse

[slate falcon]

howew

[slate falcon]

i thought so

[runic violet]

The culprit is the apex?

Bruh

[harsh matrix]

yes

that's what is producing a ghost pupil

[runic violet]

Welp

There are alternatives

Many 0.8x reducer/flatteners

I do wonder if it's something with your specific apex or will all of them do it lol

[harsh matrix]

I wonder that too

[runic violet]

Know anyone with one lol

[harsh matrix]

nope

[runic violet]

Around you

[harsh matrix]

none other than you

[runic violet]

I don't have a ghost pupil

I can tell you that

But that's about it

[harsh matrix]

my best guess is either age of the corrector, state of the coatings on the front element, or proximity to the secondary mirror

[runic violet]

Do you have a reliable way of finding it

So you can make tweaks to see what makes it go away

[harsh matrix]

I did think about giving a 0.8x reducer/flattener a try before, and then forgot about it

[harsh matrix]

yes

i found it during ray tracing

it looks like an eyeball

i thought it was my eye until i realized it doesnt move with my eye

it fits inside the spot on the secondary mirror too

[runic violet]

Drop in the 0.67x

See if it goes away?

[harsh matrix]

I do not have that reducer anymore 😭

but that one had it's own issue

[runic violet]

Do you have any reducer

What issue

[harsh matrix]

I think it was also related to ghost pupil

one moment

[runic violet]

Lemme dbe a flat

But I have only struggled with light leaks that look nothing like this

[harsh matrix]

this

using this reducer at 55 mm of back focus created this

[runic violet]

Do you know anyone around you

[harsh matrix]

on both the RC8 and my 6

[runic violet]

Who has any reducer

That you can borrow

[harsh matrix]

nope

[runic violet]

Literally anything

[harsh matrix]

i have to buy whatever next

[runic violet]

Even a coma corrector

Or any piece of shit with a converging lens element

That reduces focal length

[harsh matrix]

i have the stock quattro coma corrector i could throw in

[runic violet]

Do that

[harsh matrix]

0.86x reduction

[runic violet]

Good enough

Real question though is why doesn't it calibrate out

Yeah I have that in my flats

But it's never bothered me

Is it because it calibrates out completely or it calibrates out enough due to being in a dark sky

But I do like 200 hours of data so it should show up eventually

I will look at the other rcs flat and see if it has it

[harsh matrix]

Great!

I can try the coma corrector in a little bit but it will require some guess work.

Im not sure exactly where the point of focus "would be"

[runic violet]

Okay

[harsh matrix]

Now im not sure what exactly this ghost pupil should look like in the flats, supposedly it only contributes brightness and not structure.

[harsh matrix]

This may have been light pollution

And bad flats.

[thorny path]

im considering an RC

yall scaring me

[runic violet]

I don't think this changes advice for RCs if it's a reducer issue lol

[harsh matrix]

I found dark skies to be extremely forgiving for flats.

[runic violet]

On another note I wouldn't recommend them to most people for other reasons

[runic violet]

Yeah but things will reappear with enough integration

[harsh matrix]

As i found out the hard way

https://drive.google.com/file/d/1IJpiRZFMAy0ZLa4xtK5U_bVdYX8LlUhc/view?usp=drive_link

this is my latest master flat

[runic violet]

It's just that people don't get a lot of integration in dark skies usually because it's hard to get to

[harsh matrix]

from last night

for reference

this is a blue flat from my RC6

and that 0.67x reducer i got rid of

wait this is easier to tell

i wouldnt say i see anything in the apex flat that resembles this for one

for two, this reducer was not a reducer & flattener so im not sure how that alters things

this is the only 0.67x reducer that I know of that is known to produce this ring

I reported it to HPS and they told me as much

they did some testing which turned out to be inconclusive

they do not know the origin of this donut

*others reported it too

[thorny path]

you have the carbon star right ?

[harsh matrix]

because like me they were unable to get it to calibrate out

[thorny path]

it seems the default focuser is threaded

[harsh matrix]

that was the carbonstar RC6 yes

[thorny path]

i really like the threaded focuser, upgrade for such arent threaded

i dont like the ring clamp thing lowkey

[harsh matrix]

yes

[harsh matrix]

me neither

i had to switch it out for a baader click lock to use my apex on the 8 though

fortunately the click lock doesnt incur any kind of tilt

it returns the imaging train to the same spot every time too

that was my primary grudge with compression rings on these RC's

[thorny path]

interesting. ill try out the default focuser....

[harsh matrix]

take the imaging train off, put it back on, collimation appears to have shifted

[thorny path]

genuinly why arent we using threaded connections for imaging on newts ?

[harsh matrix]

you use the threads, this isnt an issue

[harsh matrix]

normally you cant rack the focusers in far enough to reach focus if you have to thread the coma corrector onto the end of the drawtube

[thorny path]

ahh

[runic violet]

It's hard to design a newt focuser that can also rotate and accommodate the CC

[harsh matrix]

i could have tried that with my paracorr but i would have needed another 10 mm of in traverse to reach focus

[thorny path]

imma try a 6" RC for spring

[runic violet]

Is there a reason you're not getting a newt

[harsh matrix]

he got a carbonstar newt

it had bad flares

he couldnt fix them

he sold it

[thorny path]

i dont like newts

[harsh matrix]

[thorny path]

returned it *

[harsh matrix]

oh right you got lucky

Teagan the goat

[runic violet]

I mean yes but that's just how gso is

That's not a mark on the whole design

[thorny path]

he called me and left a voice message

about he return

i kept bugging them for months about my newt issues

i think thats what saved me

[harsh matrix]

no but the flares do drive some people crazy

[thorny path]

actualy a used newt may do well

hmmm

slow newt idk

[harsh matrix]

I don't think I'd care too much personally since halos dont even bother me

[harsh matrix]

150 pds or 200 pds

im thinking skywatcher bro

i really like my quattro now that it's not being stupid

just dont use the stock CC

it's hot garbage

[thorny path]

ive seen

[runic violet]

What do you mean by flares

[harsh matrix]

couldnt correct APS-C or my 533

[runic violet]

The asymmetric flaring from gso 6" mirrors

Or regular flaring from diffraction

[thorny path]

idk what to image at 350mm for spring.. maybe wait till 5 am and spawn camp cygnus but anyway. thats a reason i wanna get a scope with a high FL

[runic violet]

The first one is avoided by not purchasing a gso 6" mirror

The second one is avoided through aperture masking

[harsh matrix]

this mainly

i believe these come with a mirror mask

and if they dont, andy 100% installed one

[thorny path]

i had the mask installed and it didnt help much

i had 2 different CCs

[thorny path]

and didnt work

i was told it was ME

[harsh matrix]

this is an example from Valence

[thorny path]

and how I was in the wrong

[harsh matrix]

somebody in this discord who once had one

the direction, asymmetrical flares

[runic violet]

Yeah it's from the mirror figure

[harsh matrix]

he sold it

[runic violet]

This problem has existed for decades

I have seen many many people with it

[harsh matrix]

that's what drove these guys to insanity

[runic violet]

I just don't recommend gso 6" f/4 mirrors

[harsh matrix]

every image on astrobin

[runic violet]

They're shit

[harsh matrix]

💀

[thorny path]

f5 newt perchance

[harsh matrix]

search Apertura Carbonstar 150 in equipment and go through every image

[thorny path]

ill see whats on the used market

[harsh matrix]

every single one has flares

[runic violet]

You unfortunately got a shit mirror, if you get a not shit mirror it won't be so bad

[harsh matrix]

matching this figure

okay 3nm filters got here

[runic violet]

Getting a pds newt or a quattro will be good, but then you have to yeet the focuser someday, install aperture mask, and maybe yeet the entire tube if you become a maniac

RC is the same deal though but with decoupling

[thorny path]

i keep forgetting that part

[runic violet]

But the RC is not fast and is not flexible in FL

It holds collimation better but if you're not a remote imager that's not that important

Newts are easier to collimate

Just way more touchy

[harsh matrix]

good news

theyre what i ordered

and theyre in good shape

[slate falcon]

you can see the secondary veery well

[harsh matrix]

buddy stored the cases in a place that made them get scratched up to all hell but the filters are unscathed

[harsh matrix]

maybe

it does look a lot like what was staring back at me the other night

[slate falcon]

[thorny path]

do some form of barlow CC exist ?

i see one for 500 bucks

[harsh matrix]

I may grab a 0.8x reducer/flattener any way, it would allow me to use a rotator

[harsh matrix]

the paracorr is basically a barlow

it has a 1.1x factor to it

[thorny path]

hmmm

good to know

[harsh matrix]

there are others but im unaware of what they are

[thorny path]

i wanna do galaxies so FL is what i want

f5 newt or even f6

ill weigh my options

[slate falcon]

get a 0.33 reducer

[thorny path]

?!

thats a thing

[harsh matrix]

i doubt it

if it was you couldnt reach focus

[runic violet]

Yes but you can also combine a cc and barlow

The 0.33x is a thing

It's for Scts

[harsh matrix]

build your own coma corrector

[runic violet]

It's trash

[harsh matrix]

BYOCC

[runic violet]

The only sct reducer that's any good is the starizona

The Meade japan sct reducer is fine for visual though

[thorny path]

i see a 6" f6 newt on astromart with a losmandy rail nvm... pick up only

[harsh matrix]

alright what 0.8x reducer/flatteners are available for use with RC's that are made well?

[thorny path]

900mm is nice

[runic violet]

The wo one

I don't think the TS 0.8x 2" is good for apsc

But the 3" 0.8x is good for FF

[harsh matrix]

my god

[runic violet]

Yeah but mount and seeing

[thorny path]

my eq3 onstep will be ok

https://www.teleskop-express.de/en/ts-zubehoer-31/adapters-tilting-327/adapter-for-decoupling-the-focuser-from-the-primary-mirror-cell-with-tilt-flange-18761

interesting

FL is something ill consider well. I think i should be ok with anything under 1000mm. a reducer 6" rc at 890 seems fair for me

[harsh matrix]

WO has a lot of 0.8x reducers

[runic violet]

This does not inspire confidence

[runic violet]

The RC one specifically

[thorny path]

they be named Flat7a and then it turns out to be a .8 reducer

[harsh matrix]

he's screwing with you lol

[runic violet]

What about 8"

[harsh matrix]

the Dr Flat Master?

[runic violet]

Yes

[harsh matrix]

oh i wont be able to use that

that's for the 12"+ only

M 92 threads

[runic violet]

They only say that because they only sell 12"+

But yeah threading it on is an issue

And it's also really expensive

Probably not worth it for you

[harsh matrix]

It won't be worth it, no.

i think the pupil thing will still be an issue regardless of what glass i put in, but im still not aware of the extent of how it manifests in flats

supposedly it doesnt affect the lights

which means whatever was affecting my RC6 was not the ghost pupil if that is true

okay i think this ghost pupil thing isnt a problem period

seems to be related to reflections with stars and not much else

as far as potential structure making it into an image goes

i think the full image of what i saw projected on the secondary is either way too big or too small to be anywhere near focus

so it may add brightness only

[runic violet]

Let me know when you inevitably piggyback a msgr rig to your rc

[harsh matrix]

https://tenor.com/view/popcorn-minions-popcorn-day-laugh-gif-5026739

i was working on one but i cant get it to function as i need it to

[runic violet]

Why

[harsh matrix]

i got a rokinon 135 but it's the wrong mount

it is micro 4/3 not canon

i have only mono cameras

[runic violet]

oof

[harsh matrix]

L after L

[slate falcon]

ive done that!!

it worked well

[harsh matrix]

[slate falcon]

minus the ca ofc

and the slight aberration at the corners

[harsh matrix]

anyway

i wont lie

if the dust calibrates out again

[slate falcon]

aanndd the slifgt field curvature

[harsh matrix]

i think where im at will be doable

i fixed the ringing in the corners i believe

so we are winning atm

[harsh matrix]

💀

what size cam

[slate falcon]

8mm

hey, it was using 1.25" lenses

[harsh matrix]

[slate falcon]

it was also a 0.7x reducer

[harsh matrix]

o

that explains enough

[slate falcon]

its still suprising it managed to correct up to like 6mm tho

[runic violet]

One of my favorite parts of the hobby is stacking correctors in the most cursed fashion and getting excellent results out of it

[slate falcon]

i wanna put an adc with my cc to see what happens icl

[runic violet]

Who needs ray tracing when you can do trial and error

[harsh matrix]

true

oh speaking of which

[runic violet]

Stacking a sw/GPU quattro cc with the AP 0.67x makes for a decent sct reducer

[harsh matrix]

i pushed the top most knife edge baffle in the baffle tube up high enough to completely obscure the inside of the baffle tube extension from the center of the camera, without blocking parts of either mirror

but that obscures more of both mirrors near the middle to edge of the sensor

should i keep it where it's at, would this be a major problem long term, and could this be the reason why the dust has returned?

[runic violet]

Only one way to find out

[harsh matrix]

alright

hopefully it is clear and not windy tonight

[slate falcon]

tbh i could probably make an apo with this

[harsh matrix]

I am a fan of the smoother transitions of the high to low points, i think it would help with correction, but im not sure the middle will correct just going off of my test result last night

[runic violet]

I'm willing to bet 10 trillion 1st gen Zimbabwe dollars you can't

[harsh matrix]

it seems like no matter what i do, the center wont correct

[harsh matrix]

need ED glass

[runic violet]

Idk maybe something in there is ED

If not then yeah it's impossible

[slate falcon]

idkkk

[runic violet]

Unless superchromat or something like that

[harsh matrix]

*if you look at the inner most edge of the dust motes, it got narrower because the knife edge baffle went up farther

[slate falcon]

(2 of the elements there are )

[harsh matrix]

hmmmmm

aint using this one though

[slate falcon]

these 2 tho

[harsh matrix]

that's a big chip

[slate falcon]

im not gunna use that no

or the 2 handmade plastic lenses either

[runic violet]

This is going to fail but I fully support messing around with lenses

[slate falcon]

[harsh matrix]

true

optics are cool

[slate falcon]

i do also have an actual flattening lens but thats being used in my guidescope

[harsh matrix]

yay looks like the wind will die down after sunset

[runic violet]

Can definitely build an army of guidedscopes

[desert locust]

It always becomes a microscope

[slate falcon]

it worked until something got misaligned and the ca became awful

everything was genuinely running perfect (exept field curve)

until it unaligned

[tulip iris]

Bruh

[frosty shard]

Join us...

[digital nexus]

Who has the reducer for the RC

How the hell do I know if my backfocus is ok

[harsh matrix]

I do

[harsh matrix]

You look at the corners

[digital nexus]

no like before i image\

[harsh matrix]

Measure it

Calculate it based on your existing camera, extension tubes, filter drawer, OAG thickness whatever

[digital nexus]

i have 56 i think to the visual back

[harsh matrix]

You have a ZWO 533 MC Pro so that's 17.5

[digital nexus]

Camera - 6.5
11mm ring
Filter Drawer - 20mm
OAG - 16.5mm
Adapter - 2mm

56

[harsh matrix]

That is good then

[harsh matrix]

Yeah that will work

[digital nexus]

now will I need both m90 extensions?

[digital nexus]

Doesnt the filter add some backfocus too?

And isn’t the reducer supposed to be 55

[harsh matrix]

Technically but I never count it

[harsh matrix]

Yes but with a 533 you wont be able to see a difference between 55 and 56

For reference

My 533 imaging train is at 59 mm

I cant tell that anything is wrong.

The RC is super forgiving with back focus and reducers.

[digital nexus]

oh

[harsh matrix]

Yeah

I wouldnt sweat it

You're good

Better than mine is

[digital nexus]

I put everything on the mount. Doing so makes it so I only need to plug in a few cables

RC: camera usb, camera power, EAF (soon)

71f: camera usb, camera power, EAF, dew heater

So I just swap my imaging train and boom. Easy rig change

[harsh matrix]

That's exactly the sort of thing you should do.

[digital nexus]

Cisco rack on the mount

[harsh matrix]

You made it even easier than I had it

I had to swap a lot of hardware and cables over when I did that stuff.

[digital nexus]

Now will I need both of these m90 extensions?

Kinda looks like the focuser has one

[harsh matrix]

I think you need to take one of the small ones off and then you're good

[digital nexus]

Same for without reducer?

[frosty shard]

What's your imaging train?

If you have no filter wheel you should be okay

[digital nexus]

533, filter drawer, oag

[frosty shard]

The manual also has some recommendations but I think this is fine
https://www.highpointscientific.com/amfile/file/download/file/2017/product/13324/

[digital nexus]

yea but I’m using a different focuser, so idk if it’s different

[frosty shard]

Ohh right I forgor

I should have noticed

How much travel do you have in your focuser?

[digital nexus]

It kinda looks like my focuser has a spacer already…. So I think il take the smaller one off

[digital nexus]

uh 4 inches

9.5 on the focuser. Idk the units

[frosty shard]

That'll be millimeters

[frosty shard]

Yeah take one off and you'll have plenty of travel to work with

[digital nexus]

k

I’m getting very close to first light now… after 5 months

[frosty shard]

Good to finally see my old reducer get some use

[digital nexus]

yep. Although I’m probably taking it off for galaxy season

[frosty shard]

Good call

[digital nexus]

I’m doing a project with Super and our imaging scale is basically identical with his rc10 and whatever his cam is

[frosty shard]

You know what your first light image will be?

[digital nexus]

Probably M100 since that’s what our target is

Although with all these clouds, I think Cygnus will be back the next time I image

Collimation is my next step, it’s warming up, 30F at night. So I think il be able to do it

[harsh matrix]

Mb

You dont need any extensions with the reducer

You do need the 50 mm and a 25 mm extension without the reducer.

Forgot mb

[digital nexus]

ok

[harsh matrix]

i spent like 2 hours collimating my RC

and i think it is still chalked

[harsh matrix]

im pretty not happy rn

[slate falcon]

:)

hope you feel not as unhappy soon :3

[harsh matrix]

this is why i am not happy

this is basically the bottom right corner

center

all the corners

the stars are not supposed to be round near the corner and then lines in the middle

[slate falcon]

wha

[harsh matrix]

wtf is this

[slate falcon]

how have you reversed the collimation 😭

[harsh matrix]

bad on axis astigmatism

[harsh matrix]

that's not the problem

[slate falcon]

so the center being off isn't the oroblem?

[harsh matrix]

that is the problem

focus isnt the problem

[slate falcon]

i meant collomstion

[harsh matrix]

now you say collimation

[slate falcon]

still waking up

[harsh matrix]

I adjusted the collimation

because the whole field was comatic

the astigmatism was all over the place and horribly unbalanced

it was awful

i tried to fix it tonight but every time i fixed the coma on axis, the astigmatism off axis became unfixable

i would have spent more than 2 hours if i kept going

doesnt help that it was 40 degrees F outside

[slate falcon]

have you potentially pushed the secondary too far forward

or moved the primary closer

?

[harsh matrix]

it's possible the secondary moved closer to the primary when i tightened the collimation screws on it

[slate falcon]

yea was thinking that

[harsh matrix]

do you think i should loosen the screws on the secondary?

they were alright semi tight so tightening them more was probably overkill but the secondary has had a habit of wandering

[slate falcon]

maybe try moving the middle screw up a lil but thats kinda risky

to make it tight

[harsh matrix]

nah

it's a phillips head screw

i wont have enough leverage to move it with the other 3 even being as loose as they were prior to me tightening them

after DBE

it isnt nearly as bad as i expected.

i still have a problem

and it is unrelated to the scope now

it's the reducer

[slate falcon]

its veery slight

[harsh matrix]

yeah

cant remove it entirely

DBE wont do it

i have the tolerance set as low as it will go and the smoothing set to 0.1

still not enough to clean it up 100% but this would be easy to bury with a lot of integration

ill show the raw one too

it's almost a perfectly smooth top to bottom gradient

with the exception of the vignette darkening in the corners

ngl if i want to go the rest of the way, i might have to take the reducer apart

which is hellishly sketchy

[slate falcon]

i dont advise you do that tbh

[harsh matrix]

that's why i dont want to do it

it's not smart

[slate falcon]

it isnt no

[harsh matrix]

alright no matter what i do i cannot remove the gradients in a simple manner

it has to be a more complex/delicate DBE process every time

[slate falcon]

doesnt everyone in high bortles habe to do that

[harsh matrix]

i dont know

simple ADBE and nuke the noise

no dust

but what are the straight lines about

dafuq

[harsh matrix]

another option is to install an aggressive light cut off mask

to block off all light from reachng the edges of the front lens element

that particular group is creating the glow that is haunting me rn

ngl if this data didnt look good

i wasnt going to continue messing with the collimation

i was about to put this thing in the closet for another month

[slate falcon]

light leak?!

still?!

[harsh matrix]

doubt it

there's a bright star off that side of the frame

could be that

doubtful

[slate falcon]

i think i saw that in ur flats a while ago

[harsh matrix]

nope

[slate falcon]

so ur not talking about this giant bar between these 2 lines?

bc that giant bar is showing up in the images

[harsh matrix]

it doesnt quite line up

it's too far over

i do think you may still be on to something

maybe i should try flat darks instead of bias and see what happens

this is what this sensor's amp glow looks like

[slate falcon]

not too bad

[harsh matrix]

it shouldnt have amp glow but it does

it's not even an ADU higher than the rest of the sensor

these variations are a fraction of an ADU

but i do not see the bands

not in the bias frame

[slate falcon]

i think all cams have a little glow on the edge

that massive band (of glow) isnt on the edge

[harsh matrix]

strangely enough there is a large difference between a 0.01s bias and a 1s bias

[harsh matrix]

yeah

also may not be

[slate falcon]

huh

[harsh matrix]

might be pixel response variation which is exactly why we take flats

[slate falcon]

yea

[harsh matrix]

the edges glow on the 1s flat

bottom and top do

well

im a little stumped

you can see the bands in here

in both the light and the flat

the middle is a lot brighter than it's supposed to be of course

that's part of the final problem

but the rest of this structure is a perfect match

[slate falcon]

you could try subtract it using a circular brush that has a steady gradient

[harsh matrix]

@frosty shard is this what you were talking about? with that ghost pupil thing?

[slate falcon]

in photoshop

[harsh matrix]

yeah

but that would be a last resort

[slate falcon]

yea

[harsh matrix]

i rarely have the patience to sort that out

[slate falcon]

[frosty shard]

This... is the inverse actually

[harsh matrix]

uh

[slate falcon]

[frosty shard]

a ghost pupil adds light in the shape of the aperture

[harsh matrix]

im very stumped now

[harsh matrix]

oh so this is adding light in the shape of the dark spot

aka

the baffle

[frosty shard]

Wait is the right frame a flat?

[harsh matrix]

yes

an ABE'd flat

it's had the gradient removed

this is what the regular flat looks like

[frosty shard]

And the left frame is an uncalibrated light?

[harsh matrix]

same for the non registered and non calibrated light stack

[harsh matrix]

uncalibrated and unregistered

i applied the flat to that light and the motes vanished

[frosty shard]

Did you have any other artifacts?

[harsh matrix]

which left this behind

[harsh matrix]

yes

[harsh matrix]

this junk

it's so close to perfect 😭

[frosty shard]

Yeah considering that your lights also show this artifact it seems like baffling?

I haven't kept super close tabs on your RC for a bit – what happened to your RC since the M81 image?

[harsh matrix]

i readded knife edge baffles inside of the baffle tube

pushed the top one up high enough to fully obscure the baffle tube extension i made from view of the camera, put another below that to obscure the rest of the tube, i flocked the primary mirror retaining ring because it was glowing like the moon despite putting 3 coats of paint on it

and the most recent change was 2 nights ago, i flocked the back of the reducer because that was causing ringing in the corners

there's still some ringing but it's less pronounced, the seems to have reduced the aggression of the vignetting as well

the knife edge baffles inside the baffle tube took the bafflig problem from months back from the left, to what it is now on the right

on the left, there's a dark spot surrounded by light, then drops off again

you cant tell that it's darker than the ring because it is not DBE'd properly but i can see it with averted vision

i cant see this inversion on the right

[slate falcon]

i can just barely

[harsh matrix]

oh yeah i can if i zoom in

that explains the dark dot in the m 51 test

great

[slate falcon]

with the orange display thingy its really easy

[harsh matrix]

playing with the STF shows it isnt evenly illuminated either

dafuq

[slate falcon]

breh

[harsh matrix]

i was going to ask if this was an improvement over M 81 but this looks like a mess

ABE revealed something i was completely unaware of

[slate falcon]

[harsh matrix]

oh there's no celebration

there's still a dark ring

it's just not nearly as pronounced anymore

any thoughts as to what may have happened here?

this is my quattro data

i had a perfect field 2 nights ago

but now i have extreme tilt in the top 2 corners?

[tight lodge]

Camera tilt?

[harsh matrix]

that's all i can think of

but why

i dont know

this doesnt make sense

[slate falcon]

waiittt wahaaat

you got refractor stars D:

[harsh matrix]

its just totally out of the blue

💀

im so not happy rn

nothing will work for more than 48 hours

[slate falcon]

shake ur cc and see if it rattles

[harsh matrix]

it doesntr

i was hoping to say hey here look

[slate falcon]

okay thats good at least

[harsh matrix]

cool 20 minute exposure

yay

but then i saw the top of the image

[slate falcon]

still looks very good

just have to pray there isnt any pixel peerer

[slate falcon]

is ur cam tightneded to the correc correctly?

bc that looks like tilt after the correctir

[silver ibex]

14% is considered mild?

I find it annoying when it's 8% lol

Also, 4.6" 💀

[harsh matrix]

I got 2 of those so 40 minutes

[harsh matrix]

dont know

[harsh matrix]

astap is always wrong

but quattro FWHM is always huge

[harsh matrix]

it should be

i dont know and i havent checked

i havent touched the camera in 4 or 5 days now

nothing should be loose or even a little loose

[slate falcon]

have you had cold nights?

[harsh matrix]

tonight

[slate falcon]

how cold?

[harsh matrix]

40 F

down from around 65 F last it was out

[slate falcon]

huuh

[silver ibex]

In normal units?

[slate falcon]

thats not too much tho i dont think

[harsh matrix]

i dunno

5 ish C to like 15 C

not sure

[silver ibex]

It's 4.4°C

That's not too cold

[harsh matrix]

well this is texas

people start freaking out when it hits 8 C here

[slate falcon]

do you keep the rig outside?

[harsh matrix]

no

[slate falcon]

whats ur room temp?

[silver ibex]

I would hope around 20°C or so, that would be a significant shift in temperature indeed

[silver ibex]

Then it is cold

[harsh matrix]

yes

[harsh matrix]

72 F

maybe?

[slate falcon]

it could have slowly shifted appart

but idk

[harsh matrix]

i dunno either

ill look at it tomorrow

it didnt shift after the meridian flip

just now

so something moved and then stayed after it moved

[slate falcon]

huuh

[harsh matrix]

how would you know if this is after CC tilt?

[slate falcon]

its got the shape of off stars caused by refraction off axis

but if it was the entire focuser

it would have regular reflector stars

(afaik btw, may not be fully true)

[harsh matrix]

hmmmm