Ritchey–Chrétien enjoyers thread

[harsh matrix]

To the point im a little uncomfortable having it out there.

No because I genuinely expect no change but I can try that while I image tonight since I am still willing to bet it wont change anything.

No because I genuinely expect no change but I can try that while I image tonight since I am still willing to bet it wont change anything.

[runic violet]

Have to completely rule out light leaks one way or another

If it's a light leak you can rejoice, if it's not a light leak time to cry

[harsh matrix]

There's a double layered black trash bag covering the back half of the tube all the way to the camera now.

If calibration still fails...

We did our best.

[frosty flicker]

just realised this thread has more messages than #1020657687291252797

next most is planetary imaging

[runic violet]

If only I can get my hands on it smh

[harsh matrix]

just

i dunno

defy physics

[runic violet]

what

[harsh matrix]

don't ask

[runic violet]

[quartz meadow]

I feel like half of the messages is troubleshooting with Veloren

[frosty flicker]

Defo

[harsh matrix]

me malding about how nothing works

getting baited by the scope randomly working for a single night

then going back to not working again

that's the circle of life atm

[quartz meadow]

the bermuda triangle

[harsh matrix]

speaking of issues

the RC reverted to triangle stars after the af run i forced

no idea why it chose to do that

it never ends

[frosty shard]

So I've been working on a little something...not done yet but I wanted to share it with some people on Discord and I canceled Nitro so I need to upload it somewhere that lets me embed it lol

[harsh matrix]

The bag caused a snag

The worst part is that I tested the config briefly last night and didnt catch anything worrying.

[harsh matrix]

@runic violet the trashbag did not save it

[harsh matrix]

@crisp flower it's over

i dont have a clue what the dark spots are

i cant locate them in the lights or calibration frames

[crisp flower]

Xdddd

[harsh matrix]

it could be light scatter from the secondary mirror

like the surface is too rough

folks are telling me i should contact GSO and try to get another secondary to test

[crisp flower]

hmmm maybe

[crisp flower]

are u willing to?

[harsh matrix]

i guess?

im extremely demoralized rn

dont really want to try

[crisp flower]

i feel ya.. i just tried to edit my C21 and the ring is kust succh a pain to work around

really too bad as the fov on ur m51 looks so sick as well xd

[harsh matrix]

yeah

the saddest part about M 51

is that it looks amazing

genuinely pretty good data despite the awful seeing and high winds

[crisp flower]

yea

[harsh matrix]

[crisp flower]

had to push the blackpoint so much it hurt

i tried getting rid of it a little with the clonne stamp

[harsh matrix]

dang that is rough

what bortle are you in btw

[crisp flower]

About 4-5ish

Guess i'll Go and disassemble the RC now

[harsh matrix]

same here

[crisp flower]

Maybe i get the 533 to Work on the roki

[slate falcon]

i pray i dont get these issues when i get the rc6

[harsh matrix]

It's worth noting that with the trash bag double layered, I expected a very small amount of light to still get through the bag. No. It was totally opaque

I couldn't even see the sun through it so...

[frosty shard]

once I get around to it I'm gonna stack all of my frames from last night's data and see if that artifact shows up

Unfortunately, most of my frames are absolutely useless

The Orion Nebula data is fine, but it clouded up after I switched to NGC 2403

[harsh matrix]

you wont see it on orion

[frosty shard]

No I'm stacking my clouded out NGC 2403 frames

[harsh matrix]

try a stack with and without flats to see what it looks like

[frosty shard]

Yeah it'll give me an idea of whether the artifact is present and to what extent

[harsh matrix]

this is what im going to expect the no flats to look like

no flats without registration*

[frosty shard]

Lmao I have a stupid idea: take the scope out on a cloudy night and just point it directly up

take a bunch of data

I wouldn't be wasting any imaging time

[harsh matrix]

i think another reason you dont see it or at least notice it, is you dont use the noise reduction tools we have

so you might not be digging deep enough below the noise floor to know if it is there or not

once you see it you cant unsee it but it's hard to see in the first place if you dont know it is there

if it's totally absent or more uniform than mine or limepie's, it might indeed be a mirror scattering issue

[frosty shard]

I also haven't been able to get long enough integrations on dim targets as of late

[harsh matrix]

oh that too

I meant to mention that you don't get long integrations on much either

[frosty shard]

It would probably have been noticeable on my IC 10 data if it wasn't for the massive issue from the reflective adapter

[harsh matrix]

the crater doesnt manifest obviously without several hours of data

it's always there with less but it's nearly impossible to pull out when the data isn't deep

[frosty shard]

It does show up quicker on a high moon phase right?

[harsh matrix]

usually, yes

[frosty shard]

well, considering how bright clouds are here, I should be able to capture it if I just aim up on an overcast night

I also want to do this to see if my flat panel is actually uniform

[harsh matrix]

yes

this is true

i was able to capture it by imaging clouds

it has to be very overcast though

to the point where detail in the clouds is invisible becaue they blend together

although maybe not in your case considering small sensor + native focal length

[frosty shard]

That has been plenty of nights here lol

And when it's not cloudy, it's windy!

Though I will say. When I did public astronomy on campus last time, there was cirrus all over the place but the seeing was phenomenal

[harsh matrix]

me last night lmfao

i think 30 MPH wind gusts or so

i probably should have set up a little later than I did cause that was sketchy as hell

i thought my AM5N and my fixed quattro were going to hit the ground

[crisp flower]

Pleiades through light Clouds with the roki is Kind of cute

[frosty shard]

When you think the Pleiades' reflection nebulosity is insufficient

[harsh matrix]

Look at all of the nebulosity!

[crisp flower]

f2 is crazy

ive seen california nebula in a 5 sec sub through clouds

Only disadvantage i'll have is that i am restricted to Luminance as i cannot use my Filterwheel with this setup

[harsh matrix]

Hm

Yo, painted on the left, flocked on the right.

Painting did significantly reduce the intensity.

I think this confirms it is an issue with the baffling.

The reason being that the paint is doing a better job of absorbing incoming light and not scattering it.

Or thats what one would think?

The flocking material still looked pretty bright despite being pretty good at dampening light tbh.

Weird.

[desert locust]

we getting somewhere?

[harsh matrix]

Not really

There's nothing else I can try if im right.

Ive done everything I can.

[desert locust]

what about sky flats

[harsh matrix]

The above image on the left was sky flats.

Thats all im going to take for this last round of testing as well because they are what used to work best.

[desert locust]

seems to improve the ghost lens thing

also try reacoating mirrors or smt

[harsh matrix]

Not sure that was due to sky flats alone.

Tonight im doing the exact same test but with all of my 3D printed hardware removed.

I dont expect a major difference outside of a lack of what the knife edge baffles may have been causing.

Tbh the goal i have right now is to revert it back to how it was calibrating when I shot NGC 891

The luminance filter issue caught me completely by surprise and it might be worth trying it in the original configuration before drawing any final conclusions here.

[desert locust]

show

also as there anything that you did that night that was even slighly different, like cleaning a filter or smt

[harsh matrix]

No

If anything i let it get extremely filthy.

https://cdn.discordapp.com/attachments/1325030460409249867/1481844915590664203/C23_11-19-25_WM.png?ex=69b4cb1f&is=69b3799f&hm=cf35786c5d4c0a2ba52e909f5816394be3e5e6d58b7eb93e3dc6e3e867f314b6&

[desert locust]

put the filter in your air filter im dead azz

[harsh matrix]

This ended up being the lum filter stack I used for that image.

This used panel flats because the sky flats result was actually horrendous.

Like, very very bad.

This stack is almost perfect by comparison to what I have right now.

That's what's got me so suspicious atm.

[desert locust]

try panel flats then

[harsh matrix]

There's some dust motes from the filter and stuff but I think i found the problem.

[desert locust]

that could br it

[desert locust]

what

[harsh matrix]

Im going to use the tracing panel most likely

The folding flat panel i got hasnt really worked.

I put it on today because the rig balances perfectly with it.

I cant get it to balance properly without it.

[harsh matrix]

The luminance filter came loose within the 2" filter mount.

Which i didnt know until I finally cleaned the filter a couple of weeks ago.

I have absolutely no idea how long it's been like that for

[desert locust]

have you been able to image scince

[harsh matrix]

It doesn't explain why the 533 was still having dust mote issues but it may explain why the 571 didnt and then suddenly did.

[harsh matrix]

Only twice.

Last night and about 3 weeks ago.

[desert locust]

wait, try like moving around your flat panel to recreate the ghost lens thing, i feel like at a certain distance it would show up

[desert locust]

or mess with focus idk

[harsh matrix]

I could potentially play around with this tonight.

I have no idea how id do it and seeing whether or not the ring that makes the crater is present is very hard without DBE'ing the flat.

[desert locust]

im talm bout the ghost lens

also place the panel on wall and move scope

[harsh matrix]

What a funny joke

[desert locust]

unintended joke lol

[harsh matrix]

Yeah I challenge you to move this around.

It's only a meager 70 or 80 pounds.

Should be no problem.

[desert locust]

no, I mean set the scope on the floor and put the panel on a wall resting on the floor, move it backward while taking flats at increments to see if it shows up

[harsh matrix]

There's no way I can power everything and do that.

It would be much easier if I just held it and walked forward or backward with it lol

[desert locust]

wdym, its just the flat panel and the camera

[desert locust]

if so then do that

[harsh matrix]

Yeah

The camera has a short power cable lol

And it has to be plugged into a computer

Which also has to be powered.

[desert locust]

use a laptop then

run firecapture or smt

[harsh matrix]

I can see the donut of death in the lum flats using my DSD OFP2

I saw people on the book face talking about how they needed to do long flats to average out the ring enough to calibrate.

So im going to take 1 second flats, which became the standard with this imaging train after I got the OFP2, and 2 and 3 second flats.

I am going to test every avenue I can

Sometime tomorrow, if i have a chance, ill try to tracing panel as well, different distances with that too, and then I will take sky flats after the sun comes up to. I wont take them anyway, the rig will be programmed to take them.

[desert locust]

did any of my advice help?

[harsh matrix]

Not yet.

[desert locust]

ok

[harsh matrix]

Going to probably attempt this tomorrow instead.

[desert locust]

but we are getting somewhere right? you see the lens

[harsh matrix]

I see it no matter what happens so yes.

[desert locust]

oh

[desert locust]

so then why is it not correcting in flats?

[harsh matrix]

That's the million dollar question lmfao.

That's what we've been trying to figure out the entire time. 😭

[desert locust]

try longer flats

instead of 1-3 sec, do like 60-180 sec

[harsh matrix]

I did as I said above.

I cant take ones that long.

[desert locust]

why

[harsh matrix]

It will expose too quickly no matter what id do.

Flats shouldnt be more than 5 seconds max anyway or something is very wrong.

[desert locust]

what about lcg mode?

[harsh matrix]

The gain mode needs to match the lights or nothing will work so thats off the table.

[desert locust]

can i see what the flats look like

[harsh matrix]

this is what the sky flats from this morning looked like

oml wtf

the spots that were black in the test data from last night were stars in the sky flats

how did this thing see stars after the sky was supposed to be opaque

💀

[desert locust]

i feel like your flats need to be less noisy and show the ring better

so idk, more flats

take like a ton and see what happens

[harsh matrix]

i take 25 as is

[desert locust]

try like 100 idk, could make a difference

the more things you test, the more you rule ouy

[tight lodge]

You know, that bright center looks oddly similar to what I got from my RCT simulation

[harsh matrix]

oh yeah wtf

it even looks inverted

in the center

like what im seeing

[desert locust]

wait, are the flats over correcting or undercorrecting the lens?

[harsh matrix]

i think the flats are undercorrecting the crater and are over correcting everything else

[tight lodge]

Ok, the reason why the spider casts a shadow is because blender simulates light as a particle and not as a wave

[harsh matrix]

that's cringe

but i dont mean the spider

i mean the ring

i can see an inversion in the center of the bright spot in the middle

[tight lodge]

What if you literally invert that image?

[desert locust]

could be smart

[harsh matrix]

it wouldnt have the intended effect, id give you that much

[tight lodge]

I mean

[harsh matrix]

it would add to the problem,

[tight lodge]

So you think that the secondary diverging cone could be a reason for the funky flats?

In this simulation I don't have off axis illumination. Everything is on axis

[harsh matrix]

now this is a master flat from the batch i just took

[tight lodge]

This looks much better

[harsh matrix]

uhhhh

hm

[tight lodge]

Imma try off axis tonight, if you remind me😂

[harsh matrix]

nvm there's no inversion

that's really confusing

it either is a biproduct of off axis light or some behavior of light acting like a wave

[desert locust]

vro, take like 100 flats and see if it changes anything

[harsh matrix]

that isnt present in blender because it is being simulated as a particle

[harsh matrix]

i have it set to do that before sky flats in the morning

ill tell you rn you wont see a difference

the only way you can is if i have some light frames to calibrate with them

[desert locust]

why, I feel like the ring would be more prenpunced

also do you have the flats from when you shot 891 and got good results

[harsh matrix]

yes

[harsh matrix]

i would say because the ring is already about as developed as your eyes will notice by 25 or 30 flats

beyond that the difference will be near immeasurable without something to check against

[desert locust]

reuse them

[harsh matrix]

that wont do me any good

[desert locust]

becuse of filter shift?

also what did they look like

[harsh matrix]

because i cleaned the filter and the camera and because i think the filter was loose then, and because collimation is way different, and because the entire inside of the OTA is completely changed etc.

lots of reasons

NGC 891 flat on the left, and tonight on the right

and NGC 891 used a tracer panel

i just noticed you can see the crater in the NGC 891 flat

like actually the whole structure of it

wtf

[desert locust]

thats from better snr on flats

[harsh matrix]

also see how the angle the light hits the camera at changes between the two?

that's because the filter was loose in NGC 891

and i think that confirms it

[harsh matrix]

that doesnt make any sense but okay

both batches were 25 each and if anything NGC 891 would be worse by your logic since they were only 0.01s long

the ones tonight were 1 second long

[desert locust]

do more flats so the ring is better defined

still use 1-3 sec flats

[crisp flower]

I dont want to demoralize Here but the skyflats i took were between 1-6 Seconds Long and the difference they Made was 0

[harsh matrix]

it's almost like I tried to say that

[waxen mountain]

Here 8h Luminance no Calibration Frames

[harsh matrix]

this is where it stands right now after having removed the 3D printed stuff

it's quite a bit better in a lot of respects

this is with 1 second flats from the flat panel

i suspect continued calibration troubles will be do to a lack of parallelism between the primary mirror and flat panel

this is why i want to take sky flats, and why i would like to retest the tracer panel and not use this flat panel

[slate falcon]

did you put it the wrong way?

[harsh matrix]

no lmfao

there's no way you can put flocking material inside and make it stick of you put the side with the adhesive facing toward the center of the baffle tube

[harsh matrix]

as predicted, 2 second flats? no difference

left is 1 second right is 2 second

[waxen mountain]

Have you communicated with manufacturers about your Donut thingy ?

They probably know why this is happening

[harsh matrix]

i have asked a distributor about it before

they had no idea what it was or why it happens

[waxen mountain]

Damn

[harsh matrix]

nor do they know anything about fixing it

[waxen mountain]

That surprises me

[slate falcon]

ask the distributor who the designer was

then ask the designer

[waxen mountain]

Yeee

That sounds good

[harsh matrix]

GSO obviously

but GSO doesnt respond to inquiries

you can try

[slate falcon]

gso is the manufacturer

[harsh matrix]

but dont expect a response

[slate falcon]

not the designer

[harsh matrix]

good luck getting ahold of a designer

[slate falcon]

yes

[harsh matrix]

3 second flats

another null result

1,2,3

[slate falcon]

no diff

[waxen mountain]

did you use bge ?

[harsh matrix]

there's a reflection in the bottom right in the 3 second

this

this is most likely due to the very small gap between the panel part of the flat panel, and the clamp of the panel

it could be a factor as to why it doesnt calibrate my stuff, but most likely, not bad enough to be the sole factor here

[harsh matrix]

yes

[waxen mountain]

Which BGE tool do you use?

[harsh matrix]

DBE

and same tile placement

[waxen mountain]

Ahh ok

[sterile pendant]

[waxen mountain]

I use Graxpert with zero Smothing

[harsh matrix]

graxpert has too much variation in the results

for comparisons like what im doing here

[waxen mountain]

Yea

[harsh matrix]

it doesnt always output the same thing which can trick you into thinking something changed due to flats when it really didnt, it was just the way the extraction was done

[waxen mountain]

yee

I just mean that Graxpert can compensate for the calibration problems

It can remove or reduce them up to a certain point

I know that's not the real point of that

[sterile pendant]

Is the light of your panel is collimated ? I mean, are the light rays parallel between them from the panel ?

[waxen mountain]

From bge

[harsh matrix]

I wouldnt have an answer to that

[sterile pendant]

So, why do you want you're pannel parallel to the primary mirror ?

[tight lodge]

Idk if any flat pannels actually do that😅

It's a matter of having the light source far enough so off axis rays get blocked

[harsh matrix]

Because there's a chance the problem has to do with a difference between the light from the sky and the light from the panel but I am spit balling. If there's a chance it makes a difference, right now is when it matters most.

[sterile pendant]

That was rhetorical

[tight lodge]

Well, it's actually a serious matter😂

Especially with newtonians

What's up with the thumbs up?😭

[slate falcon]

thumb up attack

[sterile pendant]

I agree ^^

[slate falcon]

[tight lodge]

It annoys me 😭
I find it more friendly and wholesome to insult me

[slate falcon]

peice of shit!!!!

[sterile pendant]

I had this kind of problem with a camera lens. When I used a white screen, the flats were different than the one from the sky

[slate falcon]

you said you find it frendly and wholesom

[slate falcon]

they are yea

[tight lodge]

Could it be rolling shutter effect? Most flat pannels are PWM controlled. I'm thinking if the flats are too short you get this kind of phenomenon

[harsh matrix]

that can be it depending on the source

[sterile pendant]

When we do flats, it is complicated. Because when you acheive a certain SNR, every little difference can ruin it....
Like the difference in luminosity compare to the night sky, the camera settings, etc

[tight lodge]

Think about it. The flat pannel is illuminated from the rim. That could create a doughnut kind of shape.

[harsh matrix]

the OFP2 i have is made for astro though and was extremely pricey, I doubt it will have a flicker issue especially at 1 to 3 second flat frame lengths

[sterile pendant]

Nah, the flats were litteraly different. Even the dust spot moved

[tight lodge]

Then that was the astro leprechaun sabotaging

[slate falcon]

sorry i wanted to move it

[harsh matrix]

okayyyyyy

the stack from last night doesnt look good

with sky flats

not to mention it got more stars in the flats

[slate falcon]

😭

https://cdn.discordapp.com/attachments/807809192537882647/1387522145294356500/attachment-3-1.gif

[harsh matrix]

the thing is

[slate falcon]

i have a fix

[harsh matrix]

i probably wouldnt care

if this didnt show up in the color too

but it does

and it makes my galaxies have weird looking halos

[harsh matrix]

that you cant fix

[slate falcon]

look, no issues!

[harsh matrix]

i didnt pay for a big sensor not to use it

[slate falcon]

wheres the halos?

[slate falcon]

i was joke

[harsh matrix]

right there in the middle

[slate falcon]

a

[slate falcon]

also whats with the edges not correcting

like at all

[harsh matrix]

your guess is as good as mine

it's always been an issue

nothing ive tried works

as is the same case with the middle so

[slate falcon]

buh

[harsh matrix]

there doesnt appear to be any dust...

which is.

interesting.

the 533 was still having dust mote issues regardless of what i tried until i swapped to the shorter baffle extension i made

but this is the stock extension

[slate falcon]

hmm

[harsh matrix]

another thing im sus about is the secondary

it's not as tight as i think it should be because tightening it more was causing the entire field to be astigmatic in focus

so im not even certain if what im observing is not flexture in some form

[slate falcon]

hmmmmm

[slate falcon]

why dont you tighten the middle screw so its tighter but wont push the secondary out more?

bit risky

[harsh matrix]

because it's possible that will cause a shift in mirror spacing, enough to where my near perfect field atm is going to be really bad again

[slate falcon]

trueee

[harsh matrix]

and the center screw is a phillips head for some reason

[slate falcon]

you could push the screws out like a fraction of a mm then pull the middle in a fraction of a mm

[harsh matrix]

so getting enough leverage to move it without stripping the head when it may already be tight is going to be very hard

[slate falcon]

oh yea

idk why we still use a screw made to strip

like yea it prevents over tightening but at what cost

[harsh matrix]

the cost of never getting it out again

[slate falcon]

thermite

[waxen mountain]

here is one of the flats that worked well

its inverted

[harsh matrix]

my sky flats look perfect beyond those stars

this is so frustrating wtf

[waxen mountain]

Hmmm

[harsh matrix]

@slate falcon see anything weird?

cause i dont

i think the OAG on my quattro was leaking light

not sure if it was making it to the 533 but it was affecting the 585

i electrical tape origami'd that sucker up

[waxen mountain]

can you see somthing ?

besides the stars

i did not use darks

but in the center of the stack do you see anything ?

[harsh matrix]

no

but the quattro isnt going to have the same artifact as my RC lol

[slate falcon]

gimme sec

[harsh matrix]

6 hours of data for reference

[slate falcon]

looks good

[waxen mountain]

yee

[harsh matrix]

exactly

for Paint's sake im going to do the 100 flats thing

just so they will stop begging me to do it

[slate falcon]

[harsh matrix]

what if i just like

deal with it

you know

[crisp flower]

Not regretting Putting my RC Up for sale yet

Xd

[harsh matrix]

i find the crater isnt as severe with a reducer

it's totally unavoidable at native though

[crisp flower]

A reducer is No Option for me

I want the native fl

Maybe i'll Go for a big newt

A 250 or 300p idk

[harsh matrix]

very fair

if i can make this thing work i might get a 1x flattener, but the speed is hard to pass on.

in my skies anyway

[crisp flower]

Relatable

[harsh matrix]

if i was in bortle <5 id run native ngl

[crisp flower]

Yea its very fun ngl

Tho the f2 Run Last night was very much so as well

[harsh matrix]

that's the hard part about being in bortle "it looks like it's still twighlight out at midnight"

[crisp flower]

Xdddd

Idk If a 300 would be a Bit of an Overkill But i am tempted to try ngl

[harsh matrix]

im going to upload a comparison between the 25 flat stack and 100 flat stack as well

just to prove the point that "flat SNR" and number of flats will be irrelevant and not possible to distinguish

[crisp flower]

Might be interesting

Im Just gonna say as a warning, im still gonna annoy ppl in this Channel even when im Not owning a rc

[harsh matrix]

oh hey it's almost like i predicted that the number of flats i take wont matter

it's much worse than the sky flats result tbh

100 on the left, 25 on the right

same order

no difference

except a difference in angle of illumination or something weird af

[harsh matrix]

@slate falcon could this be the secondary moving?

right was taken with the scope pointed at the target i was imaging

left was taken with the scope parked

[slate falcon]

whaat the left image has the secondaries glow to the right

so to the left

[harsh matrix]

orrrrrrr

[slate falcon]

it could be

[harsh matrix]

could it be the flat panel moving

it's holding onto the front by tension only

[slate falcon]

if its only held by one side yea

[harsh matrix]

and it's definitely not perfectly level relative to the primary

[slate falcon]

bc if it tilts it will have the secondary shadow move with it

[harsh matrix]

in theory the whole thing is grabbing the entire front of the scope

[slate falcon]

hmm

[harsh matrix]

in practice it's not a tight enough hold

[slate falcon]

can you wiggle it when its on the front?

[harsh matrix]

that's one of my primary complaints about this panel

[slate falcon]

like when you press on a corner does it move

on the other side

[harsh matrix]

normally i can break it loose by putting more pressure than just a finger on it

the worst part is ive put pads of flocking material and tape on both the inside of the tension ring of the panel and the outside of the scope to improve grip

which this did work but i dont think it's enough

[harsh matrix]

it might be flexing enough to produce a difference at the camera but it's not enough for me to see

assuming light pressure is applied to it

if i push on it enough it will move

[slate falcon]

can you take flats while weighting one of the sides?

by pointing the scope straight up

and putting something on the corner

bc that would show movement

[harsh matrix]

this is the sketchy thing

i can probably make it fall off if i did that

i can test all of this tonight

[slate falcon]

[slate falcon]

[harsh matrix]

i have to go get ready for work tho so no more brain storming atm

[slate falcon]

work storming

[harsh matrix]

This is why I want to give that tracer panel another shot.

[slate falcon]

oki

[desert locust]

wild guess but could the focuser or something be shifting which is causing the flats to be slighty missaligned?

[harsh matrix]

Yikes look at the drastic difference. 💀

[desert locust]

the big ring around the outside is in 2 parts in the corrected image, but in the flats its uniform

[harsh matrix]

Possibly

The testing tonight may be able to eliminate that as a possibility.

[desert locust]

what does the uncorrected image look like

[harsh matrix]

Dont know

Didn't make a stack like that

Can't do it until tonight.

[slate falcon]

@frosty shard i can use a paracor with the class cass!!!!

[haughty steppe]

silver sliver galaxy?

I attempted it at 1675mm with a mono 585 sensor. Turns out collimation was worse than I thought. Could never get the colors right so I just gave up. And heres lum. 16Hrs Lum, 50Min Red, 2.5Hrs Green, 5.67Hrs Blue. I now remember why I cant get the color right 😄

[harsh matrix]

Yes

[harsh matrix]

Cause the color channels are not even close in integration.

[slate falcon]

https://cdn.discordapp.com/attachments/807809192537882647/1387522145294356500/attachment-3-1.gif

[haughty steppe]

🙄

Its fine, with new collimation, still need to touch up on the secondary just a hair, I will have a better sensor for this scope, better collimation, and a better mount

[slate falcon]

mf the collimation isnt as bad as the lack of similar colour gathering

you need to actually have ballanced colour channels!!!

5 hrs of blue and only 50 mins of red

is just asking for it to be impossible to have good colours

-# i will also say that collimation is bad but you need to work on ballancing your int

[haughty steppe]

Ik, like I said, ive got a way better image train now than before. Back then I was jumping around to different targets to often. Caused me some problems

That was captured back in october last year when I first got the scope.

[desert locust]

you know, velorens rc issues have steered me away from them

[slate falcon]

imaginee

amma get a carbonfiber rc :3c

[desert locust]

imma get a carbon fiber newt

[slate falcon]

thats why im not buying too many upgrades for my scope and mostly for my cam and stuff

[desert locust]

same, going mono soon, so I gotta prepare

[slate falcon]

@harsh matrix is this a decoupler or am i stoopid

[haughty steppe]

looks like a tilt plate to me

goes on before focuser

[slate falcon]

honestly the choice is so hard between a class cass and a rc

[slate falcon]

i got that yea

[haughty steppe]

its small rc issues. Gotta get the big truss rcs.

[desert locust]

i also realise im not a fan of slow scopes

[haughty steppe]

understandable. If I could get a 750mm scope at f3 for cheap I would.

[harsh matrix]

Not a decoupler

[slate falcon]

the secondary diff is so big

[slate falcon]

im guessing its still worth right?

[slate falcon]

why does the cc have about the same size secondary as my scope

[harsh matrix]

It wasnt for me.

[slate falcon]

aa oki

[harsh matrix]

It's only worth it if your focuser is so bad that it's not mechanically aligned close enough to be usable.

[slate falcon]

guys, hear me out

the focuser on this looks so comedic

[haughty steppe]

I had to get one for mine. It was off a good bit. But that fixed it right up

[slate falcon]

if i get a class cass im prime focus modding it anyways

[haughty steppe]

I assume classical cassegrain is what your saying?

[slate falcon]

ya

[haughty steppe]

No clue what prime focus modding would be tho.

[slate falcon]

making it so theres no secondary mirror

but a camera instead

[haughty steppe]

Oh, so its like a hyperstar for sct but instead your just putting the camera in the center

I gotta look this stuff up. One sec

[quartz meadow]

thats why i said you should get a 8" lol

[haughty steppe]

Doesnt classical cassegrain need a corrector for flat field? Or does the prime focus mod put a lens optic in front of center

[quartz meadow]

Cassegrain as in Schmidt Cassegrain or just a regular cassegrain?

[haughty steppe]

One other mention, at least with my rc, if any wire goes to the secondary by following either the top or bottom of the spider, it messes with the spikes

[haughty steppe]

classical/regular

[slate falcon]

a cc uses a parabolic primary so a good coma corrector works

buut a class cass cannot be corrected with the secondary still on with a coma corrector

i found that out

[haughty steppe]

yeah, secondary just a flat plate right?

[slate falcon]

wha?

no

its a convex hyperbola

[quartz meadow]

aren't you talking about the Schmidt plate

[slate falcon]

schmidt will not be touching this design

[haughty steppe]

No, I was thinking the secondary is just a flat reflector

[slate falcon]

it honestly isnt an issue, the only issue is price / effectiveness

[quartz meadow]

wdym

[slate falcon]

its a convex hyperbolic mirror

[slate falcon]

he thinks the secondary is a flat mirror

[quartz meadow]

sorry, this one

[slate falcon]

a large secondary doesnt limit it by much

[quartz meadow]

47% difference is much

[slate falcon]

is it really 47% if you account for off axis light tho?

[haughty steppe]

Oh, understood. The secondary is actually what gives the cc the magnification.

[slate falcon]

yus

[quartz meadow]

I vastly remember a conversation about 6" RC vs 8" RC and i can't remember if it accounted for off axis

[slate falcon]

a cc is just a really quick newt with a mirror to make it slow strapped to the front xD

[haughty steppe]

Very cool, ive nerver heard of a design like that with a camera replacing the secondary. What does that make it, f4?

[slate falcon]

uhhh depends, its either f2.85 or f 3.3

[haughty steppe]

oh wow

[slate falcon]

efficient

its why i wanna do it with a 6" bc then i get a massive fov

[haughty steppe]

Wow, reading up on it, the RC primary is actually a fast mirror to. In the range of 2-3. Then the secondary is what corrects the coma while making it much slower.

This is great knowledge to have, not great for my wallet

[slate falcon]

yea!

[haughty steppe]

That makes me reallly want to get a 8" rc or cc just to mod

[slate falcon]

you cant mod an rc to be f3

only a cc

bc no one makes hyperbolic coma correctors afaik

if you can find one thats a win

[haughty steppe]

true, its a diff primary design

still quick, just cant be corrected as easily.

[slate falcon]

yea

almost 2000mm of fl is so intriguing

(regeler cc)

[haughty steppe]

not 2000mm at f3 tho right? Unless you go for like a 16"

[slate falcon]

no i meant unmodified

it really depends if i want to wait for a white to be able to get a good enough coma corrector to use it or not

an rct would be a quicker solution

for a lot slower

[haughty steppe]

unmodified its more tho.

[slate falcon]

a 6" class cass at f12 is about 1800mm

not more than 2000

[haughty steppe]

Oh, I dont want small

[slate falcon]

ah

[haughty steppe]

I was thinking 10". Minimum

[slate falcon]

atp you should go 14"

[haughty steppe]

prob need larger mount then 😄

I only got 60lbs payload

I mean, for a 6" you wouldnt want a full sized cooled cam. It would block to much

a 12" truss tube design is almost 48lbs stock. Oh no

Yeah thats way to expensive for me rn, I only got mono cams, so filter wheel is a necessity. I forgot

[slate falcon]

ik xD

[haughty steppe]

I mean, at what point wouldnt you just buy a newts primary mirror, get a backplate milled and a custom spider milled. then put camera at the front

[slate falcon]

a newts primary is usually f4

a class cass is usually f3

and its a lot more cost effective than most noots that advertise f3 mirrors

[haughty steppe]

🤷‍♂️ Which is easier and cheaper overall

[slate falcon]

ive checked and its honestly not that much different

[haughty steppe]

https://www.ebay.com/itm/206112852907?_skw=classical+cassegrain+primary+mirror&itmmeta=01KKMRKKMY086T19VN09X5SEA4&hash=item2ffd488bab:g:HD0AAeSwSlFpqYRA&itmprp=enc%3AAQALAAAA4GfYFPkwiKCW4ZNSs2u11xB3kspl2it3USM%2BZSa8WG0w%2BMN90SaJ6XFRGxrcTkEW6tWAPy417NdK5601NAZewu%2Bya1zpfKT2YJNRgl8SvXdIKpaTr2zGIIWp5Wbd6i4egOwds4FXU25MJ65HY7G7CwK%2BocPo59cD3XILtwjvUdN9%2B%2FVmAeLjr7TT%2BlwGuAZT0CHhsrsPTwuHyRtkOqN7H72PsnxXiI%2B723aXyTlwZfwpghJfrrtSRpJpU6f4nq6Eq%2FBjI76vxfXh4rXVfb118SJylAt%2Bzf0pd5xeA2Qhxtkr|tkp%3ABk9SR9C6zpidZw

[slate falcon]

does it say if its parabolic or not?

[haughty steppe]

it does not. Its also Ukrainian so no idea

[slate falcon]

high chance its spherical

[haughty steppe]

yeah

[harsh matrix]

@frosty shard @tight lodge thinking here. Think back to this issue with my quattro.

See the big dark spot with a bright ridge?

It's functionally similar to the crater on the RC.

I fixed this.

[desert locust]

how

[harsh matrix]

I fixed it by painting the rear and sides of the secondary mirror with an exponentially darker paint.

It's completely gone now.

What if.

[desert locust]

give it a shot

[harsh matrix]

And remember the paint inside the scope is already not adequate enough, what if

[desert locust]

also see if your flats are missaligned

[harsh matrix]

The problem is the light from the primary is passing through the secondary, reflecting off of the surface it is glued to, and then bouncing back through to the camera?

[harsh matrix]

Kinda hard on an RC.

Can't access the back of the secondary.

At best it is a design flaw you cant fix.

[frosty shard]

Implying that the secondary is not fully transparent?

[frosty shard]

GET OUT REEEEEEEEEEEE
(In all seriousness I want to get more data with my scope to see how widespread this is)

[desert locust]

i shall get an f/3.7 newt

[harsh matrix]

Yes

[frosty shard]

Assuming that the mirror is at its minimum 96% reflectance, with the rest of the light transmitting through it, and is made of a slab of perfectly transparent glass, you'd have to have light pass through the silvered surface twice, which means that you'd have 0.04^2 = 0.0016 (0.16%) of the light reflecting off the primary adding to the signal

At the absolute maximum

[harsh matrix]

Before considering reflectivity of the paint behind it too.

I think i will drop the reducer after I do some final flats testing tonight.

I think ill go ahead and try to tighten the secondary as much as I can, and go over all of the locking screws on the focuser tilt adjuster as well.

Just make sure everything is as tight as it can get.

[frosty shard]

There's one other thing I've been thinking about

But wait you see this donut in the lights without flats nvm

The part I find baffling (pun intended) is that the internal reflection appears to be the same size with or without the reducer

[harsh matrix]

I find that baffling as well

I also find the fact that the intensity appears to be the same painted or not painted

Flocked or not flocked.

Literally none of the work ive done has been worth it in that regard.

Nothing ive done has made any headway in getting rid of it.

[frosty shard]

The thing is, although it looks like an internal reflection, the illumination profile is really similar to my previous issue with the reflective adapter

I know others have brought it up but what filters are you using?

[harsh matrix]

Antlia LRGB-V Pro

2" mounted.

That gives me an idea.

If it was a reflection off the front of the filters, shouldnt it be way beyond the focal plane though?

[frosty shard]

I don't think it's the front of your filters. I think it's the edges.

An internal reflection from a ring has a specific profile that doesn't give you a sharp image of the entrance pupil, but it can give you a fuzzier counterpart

[harsh matrix]

I can try my DSLR on the reducer with no filter to see what happens

[frosty shard]

Yeah, definitely do that

[harsh matrix]

Id try the 571 on its own but thats an incredibly involved process that I dont have time for tonight.

Probably will take a few flats with it to see what happens.

That will end the filter debate completely depending on the results.

[frosty shard]

Also it could possibly be your filter wheel

So if you notice, the edge of the artifact tapers off pretty smoothly in all your frames

[harsh matrix]

Including narrowband?

Cause the ring doesnt exist in narrowband.

[frosty shard]

I didn't have issues as significant in narrowband

With a reflective ring between the light cone and the focal plane, the center is going to be somewhat darker

[harsh matrix]

What happens if it is the filters?

💀

[frosty shard]

That's because the angle of incidence is very high at the center, and you have relatively little light coming in at the correct angle to make it to the sensor

But when you move off axis, and especially with a large central obstruction, you suddenly get to a point where there's a lot more light coming in

The angle of incidence has decreased, so you see more of the surface of the ring

And there's more light hitting it

[harsh matrix]

Makes sense when you put it that way. I will crash the hell out if it's the filters.

[frosty shard]

But as you move farther away, it tapers off again

Narrowband filters are gonna be significantly less sensitive to these changes in angles of incidence

[frosty shard]

If it is I'm gonna screech RC SUPREMACY all over the Astrobiscuit servers

[harsh matrix]

But if it is the filters, why does it only show up on the RC?

The large CO?

[frosty shard]

That could make the artifact more obvious, but it is the one hole on my theory

(pun also intended here)

I assume you've used the imaging train with another scope and didn't see the artifact there

@slate falcon I have to ask: do you think you could raytrace a Cassegrain with a reflective ring somewhere ahead of the image plane?

[harsh matrix]

Correct and correct.

[harsh matrix]

I did the distance test and no amount of moving the flat panel away caused a change in the ring.

The size and shape of the ring remained constant regardless of panel distance.

The only way the illumination of the ring would change was if the source was tilted around 5 degrees or more.

[harsh matrix]

not looking good for your theory atm

yup

it's faint but it is there

ah that makes it nice and easy

no pressure on the panel, and then pressure

if what is being shown there is due to the pressure and not the very minor difference in crop, it wasnt nearly enough to cause what i observed last night

so something in the scope is moving.

[harsh matrix]

tracer panel flats

[harsh matrix]

I found all 6 locking screws for the focuser tilt adjuster on my decoupler to be more loose than they should have been. They were not shake around and rattle them loose but they weren't fully tight either. Exactly the sort of conditions I was looking for.

The shift isnt enough to notice in the star shapes or if it is, i haven't noticed it, and it's not enough that you'd detect it by hand or eye by wiggling stuff on the scope, but it is enough to shift throughout the course of a night. That's the key.

[frosty shard]

Have you tried taking the difference between the frames?

[sterile pendant]

The mirror is dialectric. So 99.9% of reflexion. With this kind of mirror, you can shoot a laser on it, nothing penetrate

@harsh matrix I forgot, did you changes the distance of your secondary mirror from the primary ?

[slate falcon]

wah

i will try

[slate falcon]

they did but they pushed it back into the range of correction

[slate falcon]

tbh the center is a lot more easily extractable there

[slate falcon]

i hope your primary is oka

[harsh matrix]

I think that's the tightest part of the scope atm

[slate falcon]

[desert locust]

so I was right

[harsh matrix]

It wont be when I center my target.

[harsh matrix]

No, didnt have time.

[slate falcon]

oh yea ...

[harsh matrix]

Technically yes by accident and then fixed it.

[harsh matrix]

Hopefully this is the case.

[silver ibex]

@frosty shard What is the lowest FWHM you managed with the RC?

[frosty shard]

1.75"

In a single sub

1.9" in a stack

[frosty shard]

The mirrors in any Cassegrain cannot be dielectric; it's only feasible for flats

They only work over a limited band and their reflectivity falls off massively on curved surfaces

[harsh matrix]

GSO states the reflectivity as being 94.6% or something.

Definitely not dielectric.

[desert locust]

what does dielectric mean

[runic violet]

Polarizable material that's applied in multiple thin layers to get extremely high reflectivity

[slate falcon]

is it possible to do that to my hand?

i want a shiny hand

[runic violet]

No

[slate falcon]

why not :(

will tollens reagent work on my hand?

[frosty shard]

Unfortunately it will not deposit a shiny coating on your hand

it'll just turn gray

[slate falcon]

:(

[harsh matrix]

https://cdn.discordapp.com/attachments/1361158206461837433/1482512394734538884/image.png?ex=69b738c2&is=69b5e742&hm=996395dc355b7b42c3fe123c3e5a716dd73fc835a7f2dc8bc597c2c5559f36ca&

One more chance with sky flats.

[slate falcon]

im seeing major dust spots from doing full spectrum ap

[harsh matrix]

sky flats saved it

well

well

guess ill have to do another night of tests

i will say that any funkiness hereon out might actually be from some very small leaks I am ignoring for the time being.

potential leaks

[digital nexus]

idk if i sent this here or not

i got a laser collimator

will use it to center my focuser. then borrowing an OCAL from a club member

should be in action soon 👀

[harsh matrix]

@slate falcon everything is super tight, nothing can move, yet there's an obvious difference between the sky flats and the flat panel flats

wtf is going on

the sky flats worked this time too.

why

what

huh

[slate falcon]

sky is more diffuse and random

that could be the reason

[slate falcon]

also show!

[harsh matrix]

No i thought the panel flats were more diffuse and random tbh

the central spot is much more contained in the middle

and brighter in the sky flats

[slate falcon]

i think your flat panel is still too close

if you think about it

you are focused on the sky not the panel

[harsh matrix]

@frosty shard you asked me if the central ring ever changed size and I told you yes one time but didnt know why, now i remember

the left is before i did any work, the right is after I flocked the drawtube of the focuser

that changed the size of the ring at native

for some reason

[slate falcon]

your flats are so horrifying

[harsh matrix]

@frosty shard also sorry bro i straight lied to you because im an idiot, yes I did shoot NIR recently and yes the spot was there in the center

[slate falcon]

friesd

[harsh matrix]

yeah

[slate falcon]

dark neb in ir

binned to oblivion ovc

[harsh matrix]

Okay gonna try to snag a baader steeltrack

I can almost entirely ignore focuser related issues with one of them things I hope.

[desert locust]

its lowk not bad

[harsh matrix]

Yeah

[desert locust]

did you rule out anything shifting your flats

[harsh matrix]

I cant fully eliminate all sources of flex without fully eliminating the focuser as a potential source, but I only have bad or okay focusers on hand.

[slate falcon]

lmao

[desert locust]

try a bad one and see if it gets worse

[harsh matrix]

That mightve been what happened with my first light ngl

With the carbonstar crayford

[desert locust]

I think its shift

or you could take a flat, shake the scope and see if anything changes

[harsh matrix]

Since the sky flats worked better than everything else, I think it's sag of the focuser.

A very, very, very small amount

Because this is a R&P

[harsh matrix]

Btw guys

I tried to raise the secondary using the middle screw last night

I think it is siezed

Or the secondary is genuinely that tight.

@crisp flower Has your RC always had the crater artifact?

[harsh matrix]

No

Well yes

Tilting the source of the illumination by less than like 5 degrees wont produce the amount of movement we saw in the flats.

[harsh matrix]

The problem is that it will remain in the color channels and centering the target will create a nightmare.

Won't really be possible to correct.

[harsh matrix]

I tested that last night

Saw no difference in the appearance of the flats even extending the thing to arms length above the scope.

I think the tracer panel may work better because it is partially transparent so the scope is effectively focused on infinity.

Even if it really isn't.

[slate falcon]

whaat

[slate falcon]

a oki

[runic violet]

wat

There's no idea of focus with a flat, it's simply diffuse light coming from all directions

If the flippy is failing it will be some sort of problem with polarization/direction/improper diffusion or refresh rate or something of that sort

Or of course the classic nonuniformity

[harsh matrix]

technically it matters but for the sake of explaining whatever I was observing, I am grasping at straws to explain it.

[runic violet]

Achieving proper diffusion is important but there is no idea of focus

There isn't an image you're trying to project

[slate falcon]

yuhh uhh

the difuse light still comes from a source that isnt as diffuse

which means it has a focal point that can change

so you would need it to be similar to your scopes focus yk

[runic violet]

What

Diffusers aren't lenses

[slate falcon]

diffusers also still have a psf

[runic violet]

No?

[slate falcon]

ya

[runic violet]

I'm not sure what that phrase even means

[slate falcon]

its a diffuse one but it still has one

[harsh matrix]

https://tenor.com/view/peace-out-gif-3584473422170938815

[runic violet]

I'm not sure you know what the word diffusion means anymore

[slate falcon]

scattered light

diffusers are never properly diffuse is what im trying to say kinda

[runic violet]

If you were to characterize the effect of a diffuser it would be the convolution with a fully uniform distribution but this is a level of semantics beyond anything

[slate falcon]

it can never be fully uniform tho

[runic violet]

Sure but not in the way you're saying

[slate falcon]

is

i will probably wake up tomorow and realise ive said everything wrong so lets pick this up tomorow

[runic violet]

I think you're talking about what happens to an image of a point source after a diffuser

[slate falcon]

yea

[runic violet]

That's cool and all but I fail to see the relevance to what it does outside of the focus point of the system since flat panels are outside the focus point

That's just nonuniformity

[slate falcon]

yea

[slate falcon]

ur right yea

[harsh matrix]

Do you think I should ask DSD about it?

[runic violet]

I think you'll have to establish it as the problem before they'll listen

[harsh matrix]

Same.

[harsh matrix]

Graxpert didnt do half bad

for the next step, i ordered some weather foam strips

im going to use them to seal up the gaps in and around the decoupler

I will hopefully replace the primary collimation screws with much longer versions as well

to make future collimation much faster and easier

I want to attempt to eliminate the need for the janky "light blocker" they have over the holes in the top of the decoupler 💀

[waxen mountain]

Noice

[frosty shard]

Do you happen to know what size secondary collimation screws are used with the RC?

If you ever find out let me know

I want to replace my secondary with zinc-dipped screws

[harsh matrix]

i do not

i dont know the size of the primary ones either at this moment

[frosty shard]

Oh wait you have a different secondary assembly from me I forgot

Either way I highly recommend zinc-dipped or galvanized screws in that application

[harsh matrix]

google says this though

[harsh matrix]

should note this isnt exclusive to RC's and there doesnt seem to be a clear answer for RC's

[frosty shard]

I'm pretty sure it's M4, but the length is the important question

Also, check this sucker out:
https://www.cloudynights.com/forums/topic/995306-rc6-optical-artifact-defect/

[harsh matrix]

oh my

that looks like what happened with my 8 at native after i flocked the focuser

dafuq

[sterile pendant]

@harsh matrix @frosty shard I was suprised by your messages about the reflectivity and decided to verify again. And you know what ? It depend of the tube but also of the website we see the informations. It look like the pro version of the RC8 is 99% dialectric, but during my research, some says it is 99%, others says that is 94% dialectric… etc
So much different opinion about specs !
And because Cassegrain from GSO are basicly the same as RC (just a different mirror curvature), I also checked and there is effectivly some difference about the same telescope in the informations… very weird

https://www.ioptron.com/product-p/6112.htm

https://www.teleskop-express.de/en/telescopes-4/rc-ritchey-chretien-telescopes-75/ts-optics-gso-8-ritchey-chrtien-pro-rc-telescope-with-carbon-tube-ota-1877

https://www.telescopiomania.eu/ritchey-chretien-tubes/2837-astrograph-tube-ts-gso-ritchey-chretien-pro-rc-8-carbon.html

https://www.univers-astro.fr/en/ritchey-chretien/605-ts-optics-gso-8-ritchey-chretien-pro-rc-telescope-2031624-mm-metal-ota.html

Maybe we have to trust TS Optics, after all, they make more than half of the RC on the market

[harsh matrix]

yeah there's often not a clear answer to anything regarding these scopes on the web despite how long theyve been around

[harsh matrix]

he doesnt specify what focuser he's using, how long he's had the scope or if he'd done any work to it either

that could be a challenge to dissect

[silver ibex]

There is very little information on GSO mirrors in general, unfortunately.

[frosty shard]

Here's a background extracted G band flat I recently took @harsh matrix

This is 32 flats stacked multiplicatively

yeah yeah I should also clean my filter

[harsh matrix]

it's difficult to tell what im looking at ngl

[sterile pendant]

Ooh, bubbles 🫧

[harsh matrix]

i think i see a double lobed spot of illumination in the middle though

one here

and up to the right

but i very well may be seeing things

I do believe this was a flat from first light with my 8

with no crater... suspiciously.

[frosty shard]

For reference here's one from before I figured out the reflection problem I had

[harsh matrix]

that matches the profile of what i was seeing with my RC6

bruhhhhhh

AND THE 8

when i was using it

man

so I sold that reducer because I thought it was an issue with that

cause i didnt see this without the reducer

how does that make any sense though

the right rim of the crater in mine is on the left side of the dark spot in the center of the main reflection

[frosty shard]

Since getting the RC8 what have you changed about your imaging train?

[harsh matrix]

HPS couldnt figure out that was their own adapters making that artifact?

are you serious

💀

[harsh matrix]

everything

focuser, method of connection, light dampening inside, imaging train, okay filter wheel and OAG are the same now as back then

decoupler

reducer

[frosty shard]

Have you done the test I did to check the imaging train for reflections?

(pull everything behind the OAG out and visually inspect the imaging train with a flat panel illuminating everything)

[frosty shard]

You're still using an Askar OAG right? That should be relatively easy

[harsh matrix]

Yes

Lots of times now

[harsh matrix]

Not with the 571 train

The exit pupil of the starizona is so small that theres practically no way for a reflection to happen beyond the reducer.

And what I saw in the DSLR flats, while it was hard to tell, said one very clear thing. Whatever is going on is either with the reducer or in front of it, and not on the back side of it.

Visual ray tracing tests tell the same story.

[crisp flower]

Im Not Sure, i noticed it after flocking

[harsh matrix]

Okay because thats when it got much worse for me too.

Something that should have made it better actually made it much worse.

[bleak solar]

Hey guys, I have a few hours of clear skies tonight and I wanna get out the RC6. I want to shoot either M101 or M63 and I live in Bortle 4-5 skies. Now I want to know how long my exposure should be.
I was aiming for either 10 seconds (for sharpness) or 3-4 Minutes for details

[crisp flower]

Yeaa
Did you remove the flocking now?

From what i read Here, u managed to fix it with Skyflats now right?

[runic violet]

I bet much doubt it's dielectric because you wouldn't have a 94% dielectric coating

It might be faulty marketing from their diagonals

[sterile pendant]

It look like it

[runic violet]

They have typical aluminum coatings

[sterile pendant]

Crazy how specs can change from a site to another with the same telescope

[runic violet]

It would be a very bad idea to use dielectric coatings for the primary for example, it would be expensive, alteres the figure, and makes recoating impossible

Also it is obvious from the coating degradation of the RCs I've seen that they're normal aluminum coatings

[sterile pendant]

I know some mirrors that are make like this. But it is only some specific company

[runic violet]

Dielectric coatings are best for small pieces of glass that are replaced after a very long time

[silver ibex]

Considering the price, it has to be aluminium. And as M63 said, a dielectric primary is silly

[runic violet]

If someone wants a fully reflective primary you honestly would get a silver coating though you'll have to recoat frequently

[silver ibex]

Yeah silver is more reflective but it doesn't last nearly as long

It's easier to do yourself though

[sterile pendant]

After reflexion, I don’t know how I fooled myself with these marketing incoherence…

[sterile pendant]

Pretty rare also

[runic violet]

It's common among atmers since it's easy to diy

[silver ibex]

It's mostly done in DIY dobs from what I've seen, as it can be done by amateurs much more easily

[sterile pendant]

Yep

[silver ibex]

While aluminium coating requires a vacuum chamber lol

[runic violet]

Also observatories recoat very frequently but they use aluminum

[silver ibex]

They want optimal performance so it makes sense

The VLT does it quite often for example, there's a nice video on YT about the recoating of one of their mirrors

[runic violet]

Gemini uses silver

[runic violet]

Eh it's mostly to be wary of corrosion

For example LBT gets recoated every summer and it's nasty before the recoat

[harsh matrix]

correct

[harsh matrix]

did you flock the baffle tubes? or just the focuser? what all have you flocked?

[crisp flower]

Niiiice

[crisp flower]

I have only flocked the extention Tubes Leading to the camera

The telescope itself is unflocked

[harsh matrix]

wait

that's all it took for this to happen?

[crisp flower]

Here (ignore the Bad cable Management)

[harsh matrix]

are you sure you got the compression ring tight enough?

[crisp flower]

Yes

[crisp flower]

I am

[harsh matrix]

what about the focuser?

[crisp flower]

I dont know how i am supposed to tighten it more

[harsh matrix]

is it loose even a little?

[crisp flower]

It is in fact

I think?

Omg i can wobble the primary xd

[harsh matrix]

Yeaaaaaah

Thats why decouolers exist.

But if you can wiggle the primary without a whole lot of force, you might want to progressively tighten each locking screw until you cant move it anymore.

[crisp flower]

Just did that

They were much more loose than i thought they would be

[slate falcon]

is that a complete omegon setup?!

[crisp flower]

Almost

[harsh matrix]

Oh my