Ritchey–Chrétien enjoyers thread

[stiff mason]

And it looks great

[harsh matrix]

it's awesome

super cool to be able to see this stuff from bortle 8/9 too

i dont have to travel nearly 100 miles just to see it

[harsh matrix]

NGC 1333

[high aspen]

woaaaaa

[stiff mason]

Aw hell yeah

And thats why we love IR

[frosty shard]

@high aspen here's an RC module made from the mirror module

A more compact design than the GSO version with a faster primary and smaller secondary

[harsh matrix]

this should work

[frosty shard]

What are the artifacts on the right

[harsh matrix]

reflections from alnitak

they were right on top of the horsehead the prior night

it is this filter

the other channels dont have it

the 8 vs the 6

[tight lodge]

Holy microlensing

[stiff mason]

Its probably because its a refractor

[tight lodge]

Nope. It's because is IR

[stiff mason]

Like its worsen by the fact that its ir with a refractor

In a reflector it would probably be less

[tight lodge]

It's the Talbot effect. It doesn't matter the telescope. The pattern is generated in front of the sensor because if the repetitive pattern of the pixels, that pattern is then reflected by the filter back into the sensor

[stiff mason]

So its because of the filter not the wave lenght?

[tight lodge]

It's because of the wavelength in relation to the pixels ... well the micro lenses in front of each pixel

[stiff mason]

Is there a way to reduce the microlensing

[tight lodge]

Get a sensor that doesn't use micro lenses

[harsh matrix]

Or get a sensor with micro lenses designed for NIR light

[tight lodge]

Which most likely cost you the down-payment for a house

[high aspen]

isee

[stiff mason]

And what sensor has that

[tight lodge]

IMX 990

[stiff mason]

Not where i live here it wouldn't even be able to buy you a new car

[stiff mason]

I wish i had the money

[tight lodge]

Also IMX 461 is quite good in IR

But if you are broke... imx585

[high aspen]

me:

[tight lodge]

I did not experience any microlensing with the 585

[high aspen]

i just get halos

which i dont get in visible light

[tight lodge]

I don't get anything weird

[high aspen]

gahh

[high aspen]

i think its an issue with the internal glas protecting the sensor

bc no filters has the same issue

its like hailation xD

[tight lodge]

Yeah, that's usually the cause. And because IR wavelengths are close tho the size of the pixels (harmonics) it's much easier to generate a Talbot effect which either because of the AR window or the Filters, gets reflected back on the sensor

[high aspen]

yea

[stiff mason]

Peak

[quartz meadow]

I feel like your spikes look too "clean" and tiny lol

[tight lodge]

That's what happens when you have the secondary mirror spider flocked

For reference, this is Vega😅

[quartz meadow]

hmm I see

[high aspen]

looke kool

[frosty shard]

I just want an APS-C Starvis 2 sensor please and thank you

[high aspen]

also, you also getting the halos i get!!!!

also what uo with the ca

[tight lodge]

the OIII filter has halos

[high aspen]

buh

ig i just got defective z*o cam

[frosty shard]

Coming this Spring

[high aspen]

woa

galatys

[crisp flower]

Mini m101 and friends

[high aspen]

@frosty shard im thinking of making a greg inspired design using a parabolic primary and parabolic/spherical secondary

the secondary will be f8 and primary will be f5

ill design it and see what tweaks will need to be made

[high aspen]

the reason ill have these constraints is to make it so i wont have to custom make a mirror

[frosty shard]

If you could do a little bit of refiguring, I wonder how hard it would be to make an aplanatic Gregorian using those mirrors as a base

[high aspen]

i decided to use off the shelf mirror configuratons

and its scary

the f number

[frosty shard]

You could null out a Gregorian with a parabolic mirror and a spherical one, but I don't think that actually would get you anything meaningfully different from a Newtonian in terms of correction

Well maybe it would off-axis, idk

[high aspen]

parabolic mirror is better

p vs s

its f67 😭

[frosty shard]

I wonder what you could do with three mirrors

I mean if you can use arbitrary conics you can of course build a TMA, but I wonder if you can at least null out spherical aberration

[high aspen]

ive made it down to f45!!!!

usable!!!!

[high aspen]

im defo getting a hold of the software now tho

which im quite happy about

also, i could make the secondaries light rays run parallel and use a focusing lens

which could reduce aberations

[harsh matrix]

Bro

[harsh matrix]

Looks like cool software ngl

Optics are really cool and are becoming a potential field id like to go into.

[high aspen]

yea :D

[harsh matrix]

Also, really very good for what it is.

[high aspen]

i like to look at the aberrations of each design

[harsh matrix]

This is just barely around 4 hours of data from bortle 8, but it goes nearly through zenith, which is close to 7.

[high aspen]

its cool how they change

[harsh matrix]

This scope is very lovely to image these small galaxies with.

[high aspen]

smol boi :3

[harsh matrix]

I very much look forward to the return of the NCP Messiers

[harsh matrix]

And probably a pain to figure out how to solve

I bet it really drives home the point that no design is flawless

[high aspen]

it do

the rc has an intresting one

its defo not as cool as class casses tho

also

whats so funny is that fracs are worst lol

Mersenne Telescope

i can use 2 concave parabolic mirrors for this!!

and that would be kinda cool

[harsh matrix]

Thats why everyone here clowns on them except frac owners

[harsh matrix]

Oooo that's a neat one

[harsh matrix]

It keeps hitting me just how good this already is.

Galaxies used to take me 20 hours, minimum, to get anywhere close to this with the same amount of processing.

I got this in a quarter of the time. The potential is definitely much higher.

Plus the lum is surprisingly clean beyond the artifacts that the reducer is producing, which i currently have no way of fixing.

I found people with the same scope, reducer, cam combo as me and all of them have the artifact too.

I think that's definitely the fault of the back end of the Apex-L being M42 and not M48, which is a massive design flaw imo.

It isnt a limitation of the scope itself which makes it so disappointing.

[harsh matrix]

My quattro is the same way

Previous owner flocked the spider and the spikes are horribly underwhelming

Its nothing like my goofy ahhhh RC8

[oblique sun]

wtf is going on in that last image

[harsh matrix]

Dont ask

[tight lodge]

Your RC8 does not have the insane diffraction spiked on M45😂

Check out mine

[frosty shard]

Yeah my RC has pretty well-flocked spider vanes

I was wondering how to reversibly de-flock them

[high aspen]

yea

[quartz meadow]

that last image gave me a jumpscare

[bleak solar]

When I switch my imaging setup from my ZS61 to my RC6 does the focus point of my OAG change?

[harsh matrix]

yeah

[bleak solar]

Darn

[stiff mason]

Bro what did you used to use

[high aspen]

does blåhaj increas rct performance?

[silver ibex]

Yes.

[high aspen]

does the effect double if you have 2?

[silver ibex]

It stacks but logarithmically to not make it too powerful

[high aspen]

a oki

[high aspen]

i got 2 blåhaj :3

[frosty shard]

I had a cursed dream where my RC spider was made of foam

[high aspen]

nooo

are you okay

[frosty shard]

My RC spider is not made of foam

We good

[high aspen]

yipee

also, i found out something cursed

"cursed"

the primary is f5

lemme work out the secondary rq

[high aspen]

the f/# is now f/3

[oblique sun]

central obstruction: all of it

[high aspen]

its a 70% obstruction

[high aspen]

its 2 hyperbolic mirros

just dont look at the coma

[quartz meadow]

oh gosh

[high aspen]

the rc is supprisingly corrected until you go extremely micro

then you see the issues

like 0.4um graphs show the issues

they so difficult to correct

100um graphs show how decent they are off axis

[harsh matrix]

oh well uh

no camera has pixels that small

in visible light anyway

[harsh matrix]

i mean, yeah, this is what i observed when shooting without a flattener

you should model a CDK

corrected dall kirkham

[frosty shard]

Wait you saw coma without a flattener? Uhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

[harsh matrix]

you saw it in my images

[frosty shard]

Oh I just saw astigmatism. The stars were still very round

RCs actually do have some coma but only a tiny amount of it at 5th order

In a properly nulled RC it's effectively cancelled by the 3rd order term for any reasonable field

[harsh matrix]

that's way beyond the 8 mm in Tea's simulation

so i am not surprised whatsoever to see it at the very edges of the sensor

[frosty shard]

Maybe you have some 5th order coma at that field size

[harsh matrix]

this is likely around 5 to 7 mm out from the center of the sensor

it's much less already

it onsets quickly

[frosty shard]

Actually the best way to check is to plate solve and visualize the distortion correction, since coma distorts the field somewhat

[harsh matrix]

actually you can see the transition really well here

[frosty shard]

That is a sign of 5th order behavior

3rd order coma increases linearly with distance from the field center

[harsh matrix]

yeah the stars that are even relatively close to the edges are barely distorted

its only once you reach the extremes is when you actually see bonified distortions

oh that's 2x drizzled lol

[high aspen]

[harsh matrix]

the native aberration inspector is a little misleading lmao

[frosty shard]

That still looks like astigmatism is the limiting factor in your field, so pretty solid optics if you ask me

[high aspen]

maybe

[harsh matrix]

better than i expected ngl

[frosty shard]

You can try to reduce the coma by tweaking the mirror spacing if you feel comfortable with that

[harsh matrix]

it absolutely is the limiting factor lol

[harsh matrix]

i dont really feel like risking it

ive got it collimated perfectly atm too

[frosty shard]

Yeah I think it's still very much acceptable

[harsh matrix]

it's almost imperceptible with the reducer

also it is invisible if the seeing isnt good

all coma and astigmatism vanishes

[high aspen]

bear in mind my sim is an f6 rct

[frosty shard]

The thing with Cassegrains is that there is a mirror spacing that nulls spherical aberration, and a mirror spacing that nulls coma. The RC is designed so that those distances are the same

So if the mirrors are incorrectly figured, nulling the coma perfectly may introduce spherical aberration

[high aspen]

im guessing thats the reason that the secondaries are so big

[harsh matrix]

yeah

[frosty shard]

But I'd null spherical aberration and accept some coma

[high aspen]

bc im trying to get a small obstruction which means i have to push the mirror out

[frosty shard]

Nah it's for illuminating the entirety of a full-frame sensor

Make your primary f/2 and your secondary f/4

Then you should be able to get away with something like 40% CO

RCs can have very small central obstructions if they are designed that way from the outset

It's just that off-axis aberrations like coma aren't relevant to the planetary observers who never really go off-axis significantly

[high aspen]

waiit a minut

[frosty shard]

I'm waiting

[quartz meadow]

patience is the key

[high aspen]

what would be the f ratio of the whole thing if you combine f2 and f4

[frosty shard]

Sorry, I should be more precise. Make an f/2 primary and use a magnification factor of 4 to get an f/8 system

[high aspen]

ah, oki

[high aspen]

the software has it so any extra mirror is shaped to make the system whatever f/# you put in

[high aspen]

this is the best shape i can get :/

[high aspen]

f8 150mm rct

not bad

[frosty shard]

What are the conic constants for the mirrors?

[high aspen]

ill check in a sec

[high aspen]

hyperbolic is anything below -1 right?

[frosty shard]

Yup

[frosty shard]

Wait so the reason I was asking was because it looked like there was coma in the design, but now I think that's an artifact of the triangle shaped markers for red light

[high aspen]

xD

im pretty sure it is astigmatism

[frosty shard]

Yeah for sure the star looks nice and oval

[high aspen]

looky very oval

could be a bit of coma too tho

[high aspen]

it looks liek these stas

[frosty shard]

Yeah I think that's where the 5th order contribution comes in

[high aspen]

ya

famcy tea

[vapid patio]

@harsh matrix ehh ehH?

4hr i say a good wqork in process

[harsh matrix]

That looks nuts

[harsh matrix]

A really nice start

You are definitely Sii deficient

Unsurprisingly

Best looking channel, always the noisiest 💀

[vapid patio]

I saw the subs and thought man this is gonna be a pain so whatever

[vapid patio]

What is sii in this photo

[harsh matrix]

The red

I just assumed it would be SHO lol

[tight lodge]

And the highest SNR channel always hated

[harsh matrix]

so much so that they run SCNR at 1.00 and wonder why their narrowband suddenly sucks

[tight lodge]

This region is just

[tight lodge]

Puke color NB

[harsh matrix]

SHH raw

[tight lodge]

Bi color?

[harsh matrix]

💯

[tight lodge]

What if you shoot OIII for a lil spice on the flame nebula?

[harsh matrix]

because i will probably crop flame out in the final

this

is why

if alnitak didnt exist

i would not have to do that

[tight lodge]

But what if you do 2 crops. SHO on Flame, and SHH on Honse

[harsh matrix]

i am not going to have time to do that

my weather stops being good at the end of this week

and i dont know when it will improve

i will likely focus on flame this season but not now

i dont have time thanks to the weather

@tight lodge I can buy a mono 585 at a large discount right now

specifically 40% off

a zwo 585mm pro

shall i?

[tight lodge]

Idk... I thought you're not a big fan of the 585😅

On the Quattro might work well

[tight lodge]

I'm still waiting for good weather

[harsh matrix]

wrong

nah ive been hunting for one

[harsh matrix]

that and the roki are the 2 main uses i have in mind for it

[tight lodge]

Hey! Samy 135 + 585 was my plan

[harsh matrix]

and i planned to do it too

before you

i didnt even know you planned to do that ngl

[tight lodge]

Ah... well, I plan to get an OSC 585 and have it running along with the main rig. I'm not to keen to invest in another mono setup😂

[harsh matrix]

i already have another mono setup so the choice was easy for me

[tight lodge]

Fair point. Although, maybe in the far future when I get the 571, I will be able to use the Uranus M with the Samy

[harsh matrix]

https://cdn.discordapp.com/attachments/1070137177410912329/1438433667801157693/HH_SHH_early.png?ex=6916dd3f&is=69158bbf&hm=c52ce9961cda47cd94a16af3ab453f74136e397a31dab75fc2aa6439af460548&

early sneak peek

[frosty shard]

That doesn't even look real

The Flame Nebula looks so good too

[frosty shard]

This image just screams RC supremacy

[harsh matrix]

fr

[high aspen]

you should get a second panel with the flame in :3

[harsh matrix]

getting more rn too

[harsh matrix]

i want to

alnitak has been a bother though

this isnt an issue in the other channels, only NIR

[high aspen]

nooo :(

[harsh matrix]

im pretty sure it is the filter

also, this reflection was just about on top of the horsehead in the framing that included the flame

it was change framing or cut out the entire reason i pointed the scope here

[high aspen]

[harsh matrix]

no way to fix it either

[frosty shard]

2 panel panorama, split it into like 4 images for Instagram the same way I split my M24 panorama. Or 3 for the pins like for my Lagoon image

[harsh matrix]

Ye

[frosty shard]

The Antlia one? Welp...

[harsh matrix]

No this one is the svbony one

[frosty shard]

Ohhhhhhh

[harsh matrix]

I cant use the antlia one with the 571

[frosty shard]

Well I should get the Antlia one then for the parfocality

[frosty shard]

If you want to split an image up for your pins, you'll want the panels to have a 3:4 aspect ratio btw

Makes everything easier

That CO modulation is insane wow

Y'all owe it to yourselves to take a deep look at this image

[high aspen]

egg

[high aspen]

blue flame

[harsh matrix]

I didnt noise reduce it into oblivion

[frosty shard]

I cannot stop panning through this image

Tbh I might set this as my new wallpaper for my MeLe

[harsh matrix]

I could because it is going to be way better tomorrow and the night after

Uh

Piss

Maybe not

[high aspen]

gooooood

[harsh matrix]

The clouds are coming sooner than I thought

I can still try

[harsh matrix]

The thing that surprises me most is the separation between alnitak and the small star on the left

You could park a bus there

Ive never gotten the separation that wide before

[frosty shard]

Actually screw it I'm setting it as the wallpaper for one of my virtual desktops on my main PC

It dethroned Blueseed's Chimera Complex

That is some serious honse

[tight lodge]

Flame and NGC2023 are the most underrated targets in this region

[harsh matrix]

Hehehehe

That honestly looks nuts covering a whole screen

[frosty shard]

Oh you bet it is

[harsh matrix]

I agree

[frosty shard]

It feels like one of those wallpapers I'd download from a cool wallpaper site in 2005 or something, except it's even cooler than that

[harsh matrix]

I think once I get sufficient NIR data, that whole blanket of evaporating hydrogen is going to be like a multi layered blanket

Where it will have layers to it

It already does if you look closely

There's a thick red layer with a blue glow on top of it.

[tight lodge]

You know what? I'm sick of M31... I don't even like galaxies and I keep grinding on that dumb project. I'm doing the Honse with the next opportunity.
I can get a pretty sweet framing without Alnitak

Not any time soon... but eventually

[harsh matrix]

Do it coward

You might be able to try sun - tues

[tight lodge]

Well... that's the issue. Sunday I maybe be able to image until 11pm. Tuesday? Not a chance

But... yesterday I shot this cloud nebula

[harsh matrix]

Mans

[tight lodge]

Yeah... I have to be a responsible adult and other bs like that

[high aspen]

woa

[high aspen]

sad

[crisp flower]

Did u at least get to See some polar Lights? Xd

[tight lodge]

Nope

[crisp flower]

Oooof
Me neither tho xd

[tight lodge]

Yah... who needs em anyways

[crisp flower]

I think i wouldve been more annoyed than Glad to See em as i was ttying to eliminate the tilt in my scope

[high aspen]

woaaaa

[vapid patio]

Oh wait yeah no duh whoops

[tight lodge]

Well... atleast you got some clear skies 😂

[crisp flower]

Trueeee.. Not completely clear but good enough to Test things

Also thing that interests me..
How do u Guys set up dithering?
Im currently dithering every 2-3 frames by 3 Pixels but for some reason i am encountering Walking noise again..

[tight lodge]

do 5 o 7 pixels

[crisp flower]

Will try that
Just found it really weird as ive been doing 3 Pixels pretty much since i have a guidecam and could Dither but its just now acting up

[tight lodge]

What's your OAG pixelscale?

[crisp flower]

2 um

[tight lodge]

Damn... that's small

[high aspen]

smol :3

[frosty shard]

Is that 3 pixels of guide cam scale or 3 pixels of main cam scale?

(Though I'm still marveling at my photometric stack that somehow lacked walking noise despite the total lack of dithering...)

[crisp flower]

I think its by Guide Cam scale
I talked to pickles about it
I think i have been dithering at 1.5pixels Main Cam scale all along

[frosty shard]

Oh yeah bump that up

[crisp flower]

Wait u have photometric Filters? O.o

[crisp flower]

Will do!

[frosty shard]

No just did it with Touptek G

See #1427782559726833684

[crisp flower]

Aaaah

[frosty shard]

You can monitor this star too if you want, it's pretty easy

[crisp flower]

Was about to say how Jealous i am of that

[frosty shard]

I will get UBVRI filters in the future for sure

Probably after I defend

[crisp flower]

Same i guess
I Just need to justify another Filterwheel and im in

And a 585m maybe

[frosty shard]

Though after my flats saga, I was actually informed about something that can be an issue with UBVRI filters (or any that have partial transmission)

If the filter has partial transmission that's done with dielectric coatings, the coatings can reflect light back up at the secondary and cause flat artifacts

[crisp flower]

Oooh interesting

Tbh i have Not bothered to Take Flats with the RC yet
I probably have to get a Panel large enough to be able to do so

[harsh matrix]

Bruh

[harsh matrix]

Do sky flats

There's no excuse not to take flats

The final image will always be worse without flats, with no exceptions.

[crisp flower]

Im Always using Msgc to Deal with gradients tbh 🥲

[crisp flower]

That might be the go to

[vapid patio]

I’m swinging target to target seeing what I wanna full send on

So for now I think this is good enough

Gonna go to m31

I got a late start on all the fall targets

Weather in N.C. is unpredictable

[frosty shard]

A suitable tracing panel is $20 or less on Amazon

[harsh matrix]

I got one for about $20

[frosty shard]

I take flats every night with mine, it's pretty simple with NINA

Speaking of full sending

I am trying to decide what integration I should aim for on the Orion Nebula ISHO project

Since I'm doing a 2×2 mosaic

It's gonna be a time sink

[crisp flower]

I was about to ask

[crisp flower]

Guess Theres No excuse Not to have one then i suppose

[frosty shard]

I can probably get away with very little IR and H-alpha? But on the other hand there's a ton of depth in H-alpha I don't want to miss

I am fully prepared to sink another 32 hours into this tbh (2 hours per channel per panel, 4 channels and 4 panels)

[high aspen]

woaaa what is that

its shaped like a heart

[frosty shard]

it's the pentagon nebula

[high aspen]

ooo

ive never heard of it before

[high aspen]

i feel lied to :(

[frosty shard]

Oh I thought you were joking because it actually is called the Heart Nebula

[high aspen]

[frosty shard]

see #1436814074993184859

[high aspen]

maybe ill have to image it in ir

bc that would be really funny

[digital nexus]

RC people

if I buy this. Is there anything else I’d need to buy

[high aspen]

remote control people????

[digital nexus]

uh huh

Im not worried about my mount. It should be able to handle an RC6, frankly it could handle an RC10

[frosty shard]

(Another reason people are so insistent on using lasers is because they don't want to waste imaging time collimating under the stars, but needing to recollimate an RC is rare)

[oblique sun]

a bucket for your tears of joy

[digital nexus]

I heard il need an OAG

That’s expensive

[oblique sun]

Not really

[digital nexus]

expensive to me since I’m putting my all my money into this

I broke

[oblique sun]

also you can use your current guider temporarily

it's not like it won't work

[digital nexus]

This is everything it comes with extra

TS Optics 2-1/2" rack and pinion focuser
Tri-Bahtinov mask with parial mask (for collimation)
top vixen rail
aperture mask
Astrozap flexible light/dew shield
GSO focuser tilter

[harsh matrix]

I would find a good quality reducer as well

[digital nexus]

that can be later

I’m buying this primarily for the focal length

I’m currently using an Askar 71f, so 490mm

[harsh matrix]

Real

[digital nexus]

How would planetary be with an rc6

[harsh matrix]

You can do fun stuff like this with a RC6

[digital nexus]

Better or worse than my 6” dob

[harsh matrix]

Surprisingly good lmao

This might be with my dob

Lemme check to make sure it isnt

Okay I think that one is with the dob but this one is with the RC6

This was a pretty mediocre night of seeing too

I used a 2x barlow

[high aspen]

i wanna taste it

[harsh matrix]

You definitely want to be oversampled out the booty hole to do planetary with an RC6

Or in general

[high aspen]

oh wow

[digital nexus]

Oh wow

[high aspen]

i need to get an rc 6

to replace my 6" newt

[digital nexus]

I assume my Ragdoll 17 Pro can handle an RC6 without a sweat?

[high aspen]

shoukld do yea

[digital nexus]

Think id need a oag tho?

[harsh matrix]

Yes

Easily

[harsh matrix]

How big of a guide acope do you have at present?

[digital nexus]

30mm

[harsh matrix]

And what guide camera?

[digital nexus]

sv305 pro

[harsh matrix]

You will need a new guide scope at the bare minimum

Might as well get an OAG

[digital nexus]

what if I don’t

[harsh matrix]

Differential flexture will pay you an unkind visit.

[digital nexus]

idk that mean

[harsh matrix]

I am not familiar with that lol

[digital nexus]

SVBONY planetary camera. Garbage I need a new one

[harsh matrix]

Differential flexture results in a certain amount of trailing after a given period of time.

[high aspen]

[harsh matrix]

When I encountered it, I couldn't guide longer than 60 seconds without significant trailing

[frosty shard]

Your OTA and guide scope might not always point at the exact same place in the sky, and your guiding numbers will look good while your subs look like trailed garbage

[harsh matrix]

I was already trailing slightly by 60 seconds

In about 50% of my subs too

[digital nexus]

should I negotiate this guy?

[frosty shard]

I think as-is it's a killer deal...if you feel up for it, sure, but even at that price I would not be complaining

[harsh matrix]

You can certainly give your current guiding solution a try

Just dont expect miracles

Kitkat made a guide scope work okay for a little while but he eventually got tired of trailing subs and got an OAG

[frosty shard]

Aside from differential flexure, OAGs are more convenient IMO

If you want to swap your imaging train to a different OTA, your guiding solution comes with it too

[digital nexus]

I just can’t afford an oag if I buy it lol

[high aspen]

what if i align the 2

[frosty shard]

In the RC Facebook groups I do see some people using pretty small guide scopes so I don't think it's totally out of the question

[digital nexus]

What if I don’t guide

[high aspen]

i have a 40mm guidescope

[fringe delta]

if you dont guide ill find you

[digital nexus]

The ragdoll pro only has 10 arc seconds of PE

[high aspen]

and its already aligned to what my main scope sees

[frosty shard]

The problem is that they can bend/twist at different rates if they not absolutely locked down

[high aspen]

sabge

ive got it good enough to if i center a dso its centred on my main scope

[harsh matrix]

Dont

[digital nexus]

damn he’s selling it for cheaper than the focuser

[high aspen]

that good ig

[frosty shard]

Unless you want to stick to like 5 second subs (and even still throw out a good number of them) you will need to guide

[digital nexus]

I was joking

[high aspen]

joining :3

[frosty shard]

I mean I actually have wanted to test this myself and see how feasible it is just for fun

[high aspen]

death + destruction + rampage

[frosty shard]

Nah probably just an exploded hard drive from too much data

[digital nexus]

Can someone search 533mc pro and rc6 in Astrobin for me

It’s broken

I can’t log in

[high aspen]

stick to 0.5s subs then

smh

[digital nexus]

not bad

I like that fov

[digital nexus]

I like those stars too

[harsh matrix]

Some of them are cropped

I think all of them are reduced

17 hours on Stephan's Quintet, this was at native and slightly cropped

[tight lodge]

You mean this?

[high aspen]

ouch]

[high aspen]

i dont think ill reduce ngl

[frosty shard]

Is that your flat artifact (and if so is that from a Bessel filter)

[tight lodge]

That's what I get if I try to take Flats for the IR filter😂

[frosty shard]

What filter are you using?

[tight lodge]

Svbony

Soooo... to calibrate the IR, I used the Luminance flats

Actually ended up using the G flats. Because the L were not properly correcting

I think it has something to do with the fact that the flat pannel emits no IR💀

[harsh matrix]

If you live somewhere with minimal or less light pollution than the inner city, that would be the most enjoyable course of action tbh.

I cant really do that and expect good results in my yard because of the light pollution

Here, aperture and speed reign supreme.

[high aspen]

im b5.5ish

[harsh matrix]

I can get really good results but it takes a lot of integration time, and not shooting at the fastest possible speed available to my scope means I am shooting myself in the foot.

It would take like twice as long to get similar results at native.

A 30 hour project with the reducer turns into a 60 hour project at native.

Thanks to that light pollution.

[high aspen]

:D

[silver ibex]

Yeah every second in this thread just makes me like RCs even more lol

The difference in price between an 8" and a 10" is insane tho

[high aspen]

diff 6" vs 8" too

[high aspen]

you have to remember rc mirrors are not easy to figure either

[frosty shard]

There are two mysteries that I need to solve before I die:

• What did Anthony Hamilton say to Isack Hadjar after he crashed out of the 2025 Australian Grand Prix
• How the hell does GSO mass produce RC mirrors and sell them for that cheap

[high aspen]

yea

they must have underpaid workers or something

[frosty shard]

Unfortunately...most likely

[high aspen]

its not like any factory would ever do that riiggghhhtttt

[frosty shard]

Though I should also point out that China subsidizes its industrial sector a lot as well

[high aspen]

isee

[frosty shard]

And they might have contracts with the Chinese government actually

To produce optics for military use

[high aspen]

wouldnt be suprised

being an optics company you kinda have to take any offer you can get

tbh, any industry its like that

[frosty shard]

They'd have the incentive to develop the expertise to fabricate optics of that size and quality

[high aspen]

yea

[frosty shard]

and have equipment to rigorously evaluate optical quality

[high aspen]

yea

-# yea is the only word i can think of to agree with u rn

[harsh matrix]

Hubble has imaged NGC 891

[digital nexus]

@harsh matrix @frosty shard is there anything I should ask him?

[frosty shard]

It's a steel tube right? Ask about rust

[digital nexus]

I’m assuming it’s steel, I don’t see any rust on the pic

Ugh GSO made one ugly scope

[undone sedge]

i hate that logo

[frosty shard]

I believe that calls for some fun with vinyl wrap

[harsh matrix]

that is steel yes

alright third night of horsehead has stacked, lets see what i got

H-alpha is flawless

holy crap bro

i can see fine details that hubble resolved

that's raw

[digital nexus]

What do you have

[harsh matrix]

I am using an RC8 with a monochrome 571 sensor and the Starizona Apex-L

https://tenor.com/view/monster-versus-vs-alien-monster-vs-alien-gif-16037253809360562033

I modified my RC though

[digital nexus]

how’d you modify it

[harsh matrix]

now i almost never collimate it

[harsh matrix]

the primary mirror and the focuser are coupled together on these small RC's

so I decoupled them

[harsh matrix]

my RC6 did this though

a very high bar

right out the gate

[digital nexus]

It sounds like the RC6 I’m looking at has the primary mirror movable…?

Or collimatable

[harsh matrix]

theyre all moveable yes

the problem is that moving the primary also moves the imaging train

and any weight on the focuser gets transmitted into the primary mirror

in my experience, a light OSC set up doesnt actually impact it to a noticable degree

it's not until you get a chonky mono camera with a 7x2" filter wheel like i got is when it becomes a problem

[digital nexus]

Il be using light OSC, OAG (eventually), 533mc pro, and filter drawer

[harsh matrix]

yeah that's no problem for it in the stock configuration

i was able to get away with the chonky 571 + loaded filter wheel with the 2 coupled too

this was done while the focuser and primary were still coupled

[digital nexus]

I asked the guy if it has any rust and if he’s firm on price

[harsh matrix]

and as you can see, no problems with sharpness

[digital nexus]

Holy yea I want

Nothing like my Askar 71f

[harsh matrix]

so yeah it's not really something you should worry about

not on the RC6

i just wanted to eek a little more performance out of my scope and I am very, very pleased with the results after doing so

[digital nexus]

Yea looks like an RC6 would be a good second scope. RC6 for small and close up. 71f for more wide

Then if I get an SQA55 I got wide, medium, and long

[harsh matrix]

yup

i got roki for super wide, redcat 51 for wide, quattro for medium, and RC to hold the close to very close up

[digital nexus]

The only negative I see right now with an RC6, Collimation, moving my camera/filter drawer from scope to scope

And moving my mini pc

[harsh matrix]

i did that for a long time

it's not too bad

[digital nexus]

Il have to rework my cable management to make it easier to move it

[harsh matrix]

it's worse when you are running a mono set up and you cant get the filterwheel to cooperate with the focuser

[digital nexus]

Ugh another EAF to buy

[harsh matrix]

oh and you have to refocus the OAG every time you change scopes

[digital nexus]

Why

[harsh matrix]

not necessarily

[digital nexus]

I’d just keep the OAG in the rc6

[harsh matrix]

oh yeah you can do that lmao

[digital nexus]

or did the OAG have to be right after the camera

[harsh matrix]

i just keep the whole thing together because it is easier for me

[digital nexus]

I can keep my guide scope setup on my Askar, just move the guide camera

[harsh matrix]

nah you want the order to be camera, filter, then OAG

never have the filter and OAG reversed or life sucks

[digital nexus]

then that works out great. Since i only need to move my filter drawer and camera

[harsh matrix]

yeah

[digital nexus]

And the focus wouldn’t change since I’m just plopping my guide cam out

I have to do that with my current guide scope cause my guide cam will randomly fall out lol

[harsh matrix]

@frosty shard my favorite part about this scope is that even once 5th degree coma kicks in, the scope remains uncompromising on sharpness from corner to corner

it is truly chef's kiss

those clouds have the floofy hubble look to them

just barely

[digital nexus]

5th degree coma?

[harsh matrix]

[harsh matrix]

dont ask me

i dont really know atm

[digital nexus]

The SVBONY 30mm guide scope isn’t known for top tier built quality

[harsh matrix]

well depends on where the focus point for the guide cam is on the RC6 + OAG

[frosty shard]

https://telescope-optics.net/coma.htm#wavelength

[harsh matrix]

you will have to find the right spot again

[digital nexus]

oh hmmm

[harsh matrix]

btw with a 533 you shouldnt ever really see coma

if you do, collimation likely shifted

[digital nexus]

How precise does Collimation need to be

[harsh matrix]

up to taste tbh

i try to keep mine perfect because im unwilling to compromise quality

and fortunately, once it is set, it stays

[digital nexus]

Do you have an example of bad Collimation sub vs good Collimation sub

[harsh matrix]

plenty

[digital nexus]

Idk if it would be the same as newts

[harsh matrix]

the funny thing is

even if collimation is quite a ways out, it still is a sharper scope than a newt with bad collimation

okay this is bad collimation

it was quite a ways off here

good

these are stacks where it is a lot easier to tell

pay attention to the small stars

they show miscollimation much better than big ones

this is that raw Horsehead from the RC6 lol

it seems like i was diffraction limited with the RC6 LOL

[digital nexus]

Diffraction Limited?

[digital nexus]

I think Il use the RC6 for primarily planetary

Until I can get guiding

[harsh matrix]

Basically the limitation of resolution due to aperture size

A hard limit by light itself

[digital nexus]

looks good to me idk how you can tell

[harsh matrix]

General sharpness and the fine detail that has been resolved.

[digital nexus]

This guy used a 533mc pro for planetary wtf

[vapid patio]

@harsh matrix is 300 seconds too long for M 31.

[harsh matrix]

Yes

[harsh matrix]

Thats what I used for the planetary images I posted for you above

[digital nexus]

Why not a planetary camera

[harsh matrix]

It is unironically a very good pairing for planetary despite what dissenters say

[harsh matrix]

Too broke to buy one

[digital nexus]

I don’t see many images of planets on Astrobin

[harsh matrix]

For lum it is i should say

You can try other filters at your discretion

[harsh matrix]

Most people buy RC's to hunt galaxies, me included.

Not everyone likes planetary so not many attempt it

Also planetary heavily depends on seeing and a lot of people are not in places with good seeing.

[digital nexus]

So what’s the Collimation method thing

DSI?

[harsh matrix]

I use a defocused star

I also dont really follow any of the guides online because a lot of them dont really know what theyre talking about

Often made by people who dont actually understand how to collimate these.

They add a whole bunch of extra steps that only make it harder to do.

[vapid patio]

I’m doing Ha rgb

For RGB would you say it is OK?

I don’t wanna cook my core but at the same time not trying to have 1 trillion subs

[harsh matrix]

H-alpha 5 minutes is fine

RGB might be okay

But again, test it

Try a 300s green sub

If that blows out then go to 180s or something

180s works.

[vapid patio]

OK, I’ll stop it down to 180. No big deal.

I appreciate it

I’m very late to this target

Man Weather sucks

[harsh matrix]

this is the truest thing that anybody has ever said that was true

[harsh matrix]

very very much so

oh god i thought this was a hubble image

no

this is ESA's southern observatory

this is Hubble

dis mines

raw

[undone sedge]

adaptive optics is a dream

[harsh matrix]

seriously

[digital nexus]

Hubble love

[harsh matrix]

i really want to shoot this thing in broadband

i could get the same definition on the side facing us as the bigger scopes get

it would be a bit easier to gauge as well

@frosty shard what i find most interesting is that all of the little protostellar jets in this area around NGC 2023 show up much better in Sii than in H-alpha

(H-alpha left, Sii right)

i wonder why

that h-alpha is not altered in any way

neither is the sii

[vapid patio]

Man, that’s crazy

[vapid patio]

@harsh matrix @tight lodge when I tell Nina to slew it gives me a ascom error invalid argument but when I manual slew in Nina it works and when I tell it to park it works like man

It didn’t do a meridian flip it couldt tell it to move

I have reset everything it doesn’t work

My two goats I need help 🙏

[frosty shard]

Are you using the same stretch function for both?

If so, it might be that H-alpha is self-extinguishing

or that the temperature is too low to ionize hydrogen as effectively as sulfur (assuming that sulfur is easier to ionize, which I need to check)

It is easier

[harsh matrix]

The H-alpha is the most aggressively stretched

I love my RC breh

this was so peak

[tight lodge]

Huh... only slightly more than a new RC8

[harsh matrix]

Dear god

You better hope all that is figured correctly

[tight lodge]

It ain't. The model is not designed for SLM. Is designed for FDM printing. If I want to make it for SLM, I can make the walls as thin as 1.5mm and skeletonize almost everything inside the body

[frosty shard]

Including the mirrors?

[tight lodge]

What mirrors?

[tight lodge]

It has no mirrors

Don't make me design an RC because I already have couple of projects on queue

[stiff mason]

What even is that

What is bro making

[crisp flower]

Bro is building a roki 135 Setup and is gonna hide it in this Epic tube

[stiff mason]

Why tho

[crisp flower]

Extra layer of protection, less likely to Things Break when bumping Intro Things, maybe better for Transport and ofc a Clean optics (im Just guessing)

[harsh matrix]

ease of transportation

[stiff mason]

Ah

[tight lodge]

Not a weapon

[crisp flower]

Not yet*

[tight lodge]

Not this

[stiff mason]

Tbh looks like a speed camera with a LiDAR

[tight lodge]

It is inspired by a Javelin

[tight lodge]

The tube will be acting as the case as well. So when you want to shoot, ypu just remove the dust cap and chuck it on the mount. I will most likely try to design it to fit a monochrome setup using 1.25" filter wheel, but so far it is made to have an OSC imx585. The big lids give me access for servicing and swapping filters.

[frosty shard]

https://en.wikipedia.org/wiki/IC_4182

This is a really interesting spring target...

[high aspen]

i saw that!!

(on a sky survey )

[frosty shard]

Apparently it's one of the prototypes for the de Vaucouleurs SAm (unbarred Magellanic spiral) type

[high aspen]

ooo

[frosty shard]

Another really interesting Magellanic spiral: https://en.wikipedia.org/wiki/NGC_4395

[harsh matrix]

i tried to shoot this one

then stopped because my am5n was going wacko mode

[high aspen]

6" f9 rct framing 😭

with a 585

[high aspen]

thats pretty

[frosty shard]

do you plan to revisit it?

Actually I realized I may miss a good chunk of galaxy season next year

If I go to Australia in the spring

[high aspen]

take scooe

shoot lmc

[frosty shard]

That is very much the plan

[high aspen]

:D

[frosty shard]

Unfortunately I cannot shoot 576 panels in 2 months

[high aspen]

woaw

[high aspen]

omg 😭

[frosty shard]

The target list is

• strip mosaic with the Tarantula Nebula
• some region of the Carina Nebula (I'm thinking about the Gabriela Mistral Nebula, which was one of the JWST first light images)
• one of the great southern galaxies (M83, Centaurus A, or NGC 6744)

Oh and NGC 3603/Statue of Liberty

I think NGC 3603 is the next brightest super star cluster candidate after the Tarantula

and the only one in the Milky Way that's feasible to image in the optical band

[frosty flicker]

[harsh matrix]

an LRGB and narrowband LRGB version

[silver ibex]

@harsh matrix Are the closed tube 8" RCs coupled?

[harsh matrix]

All closed tube RC's are coupled

Including the 8's

[harsh matrix]

@frosty shard i dunno about you but i have flat calibration issues in general

seems to be the absolute worst with luminance

like this appears to be a dust spot that didnt calibrate out

i dont know what else i can try or do to fix problems atp

[frosty shard]

We'll see, I'm packing in the scope rn

And uh

You might notice a problem

[harsh matrix]

the dust motes not entirely clearing up is exclusive in lum

RGB is cleaner

[harsh matrix]

why is it parked like that

[frosty shard]

Battery died 💀

Thankfully this precarious situation is now a postcarious situation

[harsh matrix]

uh oh

progress

definitely worried about the lum flats

the color is surprisingly clean by comparison

i dont know why lum refuses to work

Hubble humiliates my tiny scope

[frosty shard]

quick look at the data

still need a lot more

[frosty shard]

That is only stretched

[digital nexus]

How does back focus work for RCs

[frosty shard]

Without a reducer, just bring the system to focus and that's all

[digital nexus]

So like my petzval quad refractor

[frosty shard]

With one, you'll probably have to do the standard 55 mm backfocus, but it depends on the reducer

[frosty shard]

Yup

[digital nexus]

good good.

Why do RCs seem like the quad petzvals of reflectors

[frosty shard]

They were designed with the goal of being astrometrically accurate (no coma or distortion) while being easy to scale to large sizes for observatories

[digital nexus]

So il prob need an OAG

How much do those go for used

[crisp flower]

U can try and do it unguided but u will Not get the best results

[digital nexus]

I have a 30mm guide scope I can use

I found an OAG for $42

[crisp flower]

Go for it?

[digital nexus]

nah if I do that I can’t afford the rc

Il just do planetary until I can afford it

I know rc6 isn’t great for planetary but it’s better than my refractor

[digital nexus]

@frosty shard @harsh matrix @dense quiver

Bought it

[dense quiver]

Nice

[digital nexus]

It ain’t an RC8 but it’s good enough for me

I just need an OAG now

[digital nexus]

@dense quiver Am i going to need a new guide camera?

[dense quiver]

Just this

Which one do you have

[digital nexus]

sv305 pro

imx 290 i think or 662 i keep hearng different things

[dense quiver]

Mono?

[digital nexus]

no

[dense quiver]

Id look for a mono one

[digital nexus]

i cnat afford one

frankly i cant afford an oag

[high aspen]

i made cheeb :3

[silver ibex]

Finally you joined the light side

I'm the only one left

[high aspen]

theres me too :c

[dense quiver]

It is what it is then. You'll have to see but I dont think you'll have too many issues

[digital nexus]

I’m going rock with my 30mm guide scope and see how it goes

It’ll be better than no guiding regardless

[high aspen]

it will be a good experiment to see how well ill perform with a similar setup

[digital nexus]

what’s your setup

[high aspen]

i got a 40mm guidescope and an sv105 or whatever it is

i originally got the guidescope to help with visual

bc the 20mm one before wasnt good enough

[digital nexus]

Now what’s that DSI method for Collimation

[high aspen]

wrong channel

[digital nexus]

why

[high aspen]

no

i sent an image

[digital nexus]

oh

[high aspen]

#💬-general-chat message

[crisp flower]

@digital nexus this

[quartz meadow]

I shall invest into an RC8 as well in the future

though the question is, is the carbon fiber variant a necessity or does the "normal" one suffice?

[crisp flower]

Im rocking a non-carbon one and im more than satisfied with its performance

[quartz meadow]

what about dew? like that's my main concern

and yes I'm aware that dew heaters exist, though the question lies in how prone they are to dew

[crisp flower]

Ive Had my secondary Fog Up one night when humidity was fairly high, but since i started to use a dew shield i had No issues with dew

[high aspen]

yipee!

[digital nexus]

Im hearing that imaging near horizon can cause collimation issues? Since the focuser is attached to the primary?

[frosty shard]

If you live in a humid or coastal area, I've heard the GSO steel tubes can rust

[high aspen]

whoever told me to design an cdk, you are evil

[digital nexus]

@frosty shard is the rc6 primary mirror coupled to the focuser?

[digital nexus]

do you have a video of this

[crisp flower]

I dont

[high aspen]

yes

[digital nexus]

is that a problem? Someone told me it caused Collimation issues at/near horizon

[silver ibex]

Yeah it's annoying, but you can decouple it; it's up to you if it's worth it or not.

If the imaging train is decently light I don't think you'll need to decouple, you shouldn't be imaging near the horizon either way

[digital nexus]

I heard the decouple kit was more expensive than the scope

My imaging train will just be

Asi533mc pro - spacer - filter drawer - oag - unknown amount of spacers - RC6

[high aspen]

this is the best i could do

its like 100* worse than planewave

a lil bit better now?

no

worse

much better

20 um smoller

planewaves are like 7um

mine are 20um

so

close

16 um nows!!

[digital nexus]

https://tenor.com/view/breaking-bad-funny-wtf-wth-jesse-gif-17336046

[high aspen]

v i o l e t h a l o

im so close to fit the airy disk

if you shoot nb you good lmao

[frosty shard]

Does Zemax have a solver for lens and mirror figures?

[high aspen]

it has an optomiser which can perfectly correct stuff

but i dont really wana use it xD

i think nb is the way to go

[frosty shard]

I want to write my own solvers actually

[high aspen]

would be cool

[frosty shard]

With my RC8 I have not had noticeable collimation shifts with altitude

But I have heard that an improperly tightened primary can cause similar issues

[high aspen]

look at this cool star :3

[frosty shard]

I had a loose secondary and that caused problems at meridian flips

[digital nexus]

If it’s coupled how can it be improperly tightened

[frosty shard]

The primary mirror uses a push-pull screw system

[high aspen]

you can do 10nm nb no problem

i say its a success

[digital nexus]

@frosty shard should I put my Askar 71f on top of the rc6

[frosty shard]

Also @digital nexus now that I remembered this:

• If your OTA plate solves to a slightly different focal length from what GSO specifies (±10 mm), don't bother adjusting it. If the previous owner didn't mess with the spacing, it's very likely correct as-is.
• I would recommend marking or noting your imaging train's focal point on your focuser for future reference in case you do need to adjust the spacing.
• In the event you do need to adjust the spacing, it's much easier than people make it out to be – I had to do it myself – the trick is to use an eyepiece

[frosty shard]

I have no experience putting anything larger than a finderscope on my RC, and that's for when I use it for visual

[digital nexus]

lol that’d be funny

[frosty shard]

You should have the headroom for it with your mount I think

[frosty shard]

Stacking them for visual?

[digital nexus]

no

Imaging

dual imaging rig

[frosty shard]

I mean you could get an MSGR dataset for all your RC data

[digital nexus]

I don’t have Pixinsight

I bought the rc6 instead

[frosty shard]

wise decision

[digital nexus]

I’m doing just fine with Siril, Grax, and SAS, so I’m not in a rush to get pix

[frosty shard]

Or downgrade your Askar to a guide scope

[digital nexus]

that’d be sad

esp when I can image with it using my dslr

[frosty shard]

Or downgrade your RC to a manual guide scope, stick an eyepiece in it, and hand guide like it's the 1930s

[digital nexus]

My Askar Rig is about 11 pounds. RC6 will be what 15 pounds?

That’s the max payload I can do WITHOUT CWs

So what’s all this? @frosty shard https://www.cloudynights.com/uploads/monthly_2025_10/IMG_84771.jpg.281f1362d0521605683b0f0ee96938e9.jpg

I know the spacers of course. idk the rest though

[frosty shard]

Tri-Bahtinov mask (top left), mirror mask (top right), some other mask (bottom left), a full set of focuser extension rings (bottom right)

[digital nexus]

Mirror mask?

This is what he said

Tri-Bahtinov mask with parial mask (for collimation)
aperture mask

[frosty shard]

GSO RCs can have imperfectly silvered mirror edges that cause extra diffraction

[high aspen]

top right looks like a mirror mask

[digital nexus]

Like extra spikes? Or bad spikes

[high aspen]

explosion

[frosty shard]

I don't care about that personally but some people are bothered by it

[digital nexus]

Got an example?

[frosty shard]

See TV Cassiopeiae on the lower right for an idea

[digital nexus]

So where does that mask go? To fix it

Also side note, weird ass target btw

[frosty shard]

Over the front of the aperture

[frosty shard]

IC 10? or TV Cassiopeiae?

[digital nexus]

The green stuff

[frosty shard]

It's an HaIRG image

[digital nexus]

Weird

[high aspen]

hai image

[frosty shard]

I have an HaRGB version as well for those with greenphobia

[high aspen]

boriiing

[vapid patio]

@harsh matrix ???

Any clue?

[frosty shard]

Are you using GS Server?

[vapid patio]

Gs?

[frosty shard]

Green Swamp Server to control the mount

[quartz meadow]

dont think humidity is going to be the problem so I guess i'm fine

[vapid patio]

ascom?

[harsh matrix]

I don't know

[digital nexus]

@frosty shard The RC6 comes with a GSO Focuser Tilter

is that compatible with the other focuser?

[harsh matrix]

The other focuser should have an adapter with it which would make it compatible, yes

[digital nexus]

https://www.cloudynights.com/uploads/monthly_2025_10/IMG_84781.jpg.884d1e7ecae8036c09cf398406d1633e.jpg

Does it?

[harsh matrix]

It is a feathertouch, right?

[digital nexus]

I don’t know

[harsh matrix]

Hmmmm

Maybe it is a baader steel track

[digital nexus]

https://www.teleskop-express.de/en/telescope-accessories-5/focusers-adapters-motorfocus-296/focusers-and-micro-transmission-92/ts-optics-2-5-rack-and-pinion-focuser-with-m90x1-connection-and-360-rotation-6970

[harsh matrix]

If i had to guess, that might have the adapter on it already

It looks to be the same diameter as the silver cuff on the stock focuser.

Oh okay

No thats good