Ritchey–Chrétien enjoyers thread

[harsh matrix]

i doubt the data will be much good from home

but i can certainly produce a teaser image

and then focus on it at the dark sky site if i can get out there again soon

i was planning on getting some more m104 data

but tbh

id rather wait till i have like 3 or 4 clear nights to work with

tonight is the last clear night i might have

for another week or 2

slight evidence of crater here

probably because of the moon ngl

[plush raptor]

my goat

[frosty shard]

@slate falcon can you simulate diffraction patterns in ZEMAX?

[frosty shard]

@crisp flower bagged SN2026kid

[harsh matrix]

printing my work is going to be harder than i expected

either that or the printer is terrible

it posterized my beautiful photo so badly

actually my mom said the ink sucks

soooooo

oh well

test print 2 didnt go any better

[crisp flower]

Hell yeah

[harsh matrix]

no SA to speak of 🫡

[versed roost]

dude its so complicated

[frosty shard]

I really need to fix the mirror spacing...

[harsh matrix]

doing 10 minute M17 subs

at the native focal length

what could possibly go wrong

holy

I had no expectations and this was even wilder than my strongest expectations

no halos

[frosty shard]

Now a featured picture: https://commons.wikimedia.org/wiki/File:Ritchey–Chrétien_imaging_in_a_tennis_court.jpg

[harsh matrix]

Oiii

10 minute subs

and it just holds

no halos thus far

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

holy

all that signal already

in 4 subs

[frosty flicker]

Holy hell

[harsh matrix]

imma turn blurX nonstellar to max

anything under 0.8 makes almost no difference

it is too focused on the hotpixels to do much lol

that's max settings for nonstellar

no flats yet btw

[slate falcon]

can i try some stuff on it

[harsh matrix]

no way

you can see the fuzzy of the disk

this is roughly 3" data

not too bad at all

especially for the altitude and the jetstream being right over my head this time of year

oh wow...

oh the compression really doesnt do this justice

this is beautiful

[slate falcon]

u got tha lil guy

[harsh matrix]

Got a couple little guys

[frosty shard]

NGC 5906/SN2026kid

Just hit with a bit of GHS and nothing else. I'm surprised there wasn't a strong moonlight gradient

[frosty shard]

@crisp flower do you want my IR data?

[crisp flower]

Gladly
I can slide U my LRGB as well

How much int has yours?

[frosty shard]

4 hours exactly, though it was under the full moon

[crisp flower]

I can very happily Provide u my tiny 80ish minutes xD

[frosty shard]

I think this is where IR as luminance might not be a bad idea

[crisp flower]

Probably

[frosty shard]

Here's what it looks like when I actually deconvolve and denoise the data

[crisp flower]

I ended Up Here Yesterday with denoise

[frosty shard]

https://1drv.ms/u/c/4f69734a5f0092dc/IQB5Y_fk_fbjRpowuQhQdJwSAW2NxpWtxVAdm8296xvuy-Y?e=6dqprx
Feel free to use this data however you wish, no attribution required

[slate falcon]

i will fry

onione

[slate falcon]

@frosty shard

secondary 1mm out and 1mm in

crazy how much changing position by 1mm effects it

1mm in vs 1mm out

5mm out vs 5mm in

11mm off axis

for all these btw

i think vel is out by like 3 mm

3mm too far back on the secondary

@frosty shard do i buy these

[frosty shard]

are you financially responsible

[frosty shard]

Can you tilt the primary and secondary mirrors by 0.25 degrees or so?

[slate falcon]

nou :3

[slate falcon]

it turns out the sampling with the 3" gold mirror would be decent

it actually seems kinda worth it

would be a nice widefield setup

[bleak solar]

okay! I have collimated my telescope, I am 3D printing a baffel extention against stray light, I have bought a dew shield and a rotator for my camera... now all that I need are clear skies 😭

[slate falcon]

0.25 deg on x axis

thats like a good chunk lol

heres 0.05

pop, 0.05 deg t, 0mm oa, 8mm oa, 11mm oa

pop, 0.25 deg t, 0mm oa, 8mm oa, 11mm oa

pop = physical optics propogation

@frosty shard

[crisp flower]

@harsh matrix Done

[tight lodge]

That's hot🤤

German Engineering

[slate falcon]

thats one yummy focusrr

[crisp flower]

hell yeah

now i just need a clear night so i can collimate it

[slate falcon]

[harsh matrix]

YEAAAAAAHHHHH

Um

I still get ring of death btw

Except it appears to be from either a light leak or excessive sky glow due to the full moon.

Either way, it's something that can be remedied

[slate falcon]

awch

[harsh matrix]

I dont see it without the moon though.

Not even evidence of it.

[crisp flower]

i have not seen it in my recent almost full moon data

though i got a little rainbow which i think was caused by a street lamp

[harsh matrix]

hmmmm

how far or close to the moon were you pointed

[crisp flower]

here

[harsh matrix]

i was probably 40 degrees away from it

[crisp flower]

im not too sure

[harsh matrix]

hmmmm

i think part of my issue is that the moon was causing a reflection inside the baffle tube

a large uneven reflection due to excessive glow because i dont have a dew shield

cant run a dew shield and the flat panel right now

im thinking about maybe 3D printing an extension for the front of the tube itself and putting the flat pannel on the front of that

[crisp flower]

i think hercules is far enough from libra for the moon to be not as much of a problem i guess

[crisp flower]

that might have played a big part in u getting the artifact i would think

[harsh matrix]

ye

it is unforunate but at least i wont have to deal with it without a moon

[crisp flower]

true

[harsh matrix]

maybe even the other side of the sky would work better

i just couldnt resist imaging M104 though

ive always wanted a color image of it

[crisp flower]

relatale tbh

[harsh matrix]

mostly because i know how May goes here and i likely wont see more clear skies until mid June

by then it might be too late

[harsh matrix]

@frosty shard looks like I got 2 globs of M104

[waxen mountain]

Bro this close up looks really peak

[harsh matrix]

I friggin 100% agree

this was WAY better than it has any business being

this should have been the anniversary photo i posted lmao

ill post it anyway

[waxen mountain]

Someday I'll get an 8" too

[slate falcon]

[harsh matrix]

this has been more fun than I ever thought

[waxen mountain]

Yeee

[harsh matrix]

this sort of cropped in high res imaging is definitely my thing

i love this more than anything else ive done in this hobby

this is the sort of thing that makes me excited to put my scope outside

[waxen mountain]

That's with my 3.4" CCT 😭

Don't talk about the Colomation

[harsh matrix]

oh well now I do want to talk about it

tis finished

[waxen mountain]

https://tenor.com/view/smiling-smiling-cat-cat-cute-kitty-gif-12097880735853048722

[crisp flower]

this peak

[slate falcon]

i think you burnt

https://youtu.be/JXdxPIeD0Ik?si=7AWT7ClLpgvQK62L if anyone is interested 🥺

[frosty shard]

JOIN US

[crisp flower]

@frosty shard i used a mix of your nir and my lum as Luminance for this one. SNR of ur data is much better than mine, but doing nir only as Lum resulted in a less sharp image

[slate falcon]

join meee

[frosty shard]

liked and subscribed

[slate falcon]

[waxen mountain]

https://tenor.com/view/poor-man-gif-23343928

[slate falcon]

you should get an array of 8"

[frosty shard]

did you tilt both at once here?

I should have been clearer, I wanted to see the difference between tilting the primary 0.25 degrees vs tilting the secondary 0.25 degrees

[waxen mountain]

Niice

[slate falcon]

only the secondary was tiled no

[frosty shard]

Oh okay

[slate falcon]

i havent done any primary tilt tests

only thought u wanted secondary

[waxen mountain]

here M51 with the same setup

[frosty shard]

I thought you said your FWHMs for were like 4" or 5"

Guess not lol

[slate falcon]

if it wasnt jpeg it wouldnt look half bad

[crisp flower]

pix says, its 4.8, whilst it estimated yours at 6.6

[tight lodge]

@harsh matrix

[slate falcon]

okay maybe if you had good snr it wouldnt look half bad

[slate falcon]

[waxen mountain]

Exactly

[crisp flower]

did u do 300 sec subs?

[frosty shard]

Oh, it's probably using pixels as the unit not arcseconds

That checks out

[crisp flower]

maybe

[frosty shard]

Nope, 120 secs

[slate falcon]

u have about 0.5 arcsec ppx ?!

[waxen mountain]

I used 800s subs !

[frosty shard]

we both do (me and @crisp flower )

[crisp flower]

https://drive.google.com/drive/folders/1rsY6TpGOesOEPfXuhBh6fS32Dq8K5Rh9?usp=sharing u can have a look at the lrgb as well if u like

i have a satelite trail in the red but its hidden enough for me after adding luminance

[slate falcon]

yummy 🤤

[frosty shard]

I think I still need to test for spherical aberration though

[slate falcon]

maybe

[frosty shard]

I can't hit the FWHMs that Veloren hits

[slate falcon]

do you know what spherical ab looks like specifically?

[frosty shard]

Yes, but only visually. It's kinda hard to see photographically

[slate falcon]

you have a brighter oval one side then a sort of almost hollow ghostly ring or shadow sorta thing

[crisp flower]

do i want to know how low he gets?

[frosty shard]

HFRs of ~2.7 in autofocus runs

I can only manage like ~4

and I don't think that is just down to seeing anymore

[slate falcon]

square filter

[harsh matrix]

that was fast

they didnt find any problems?

[crisp flower]

hmmm

[harsh matrix]

btw all of my HFR's were under 3.00 while my targets were over 30 degrees altitude

I wonder what it would have been near zenith

[frosty shard]

In autofocus data or in long exposures??

[harsh matrix]

in 5 and 10 minute subs

[frosty shard]

Holy fr*ck

[harsh matrix]

cant count autofocus because i bin for that and it brings the HFR's down to impossibly low values

[crisp flower]

is autofocus alwys measured in hfr? (ight be a dumb question right here)

[frosty shard]

Yeah, FWHM is not robust enough for autofocus

Defining FWHM becomes problematic when the profile has a giant hole in the center

[slate falcon]

[harsh matrix]

yeah

[slate falcon]

how do you check for globs in your image btw?

[crisp flower]

got it.. bc iam not too sure onn how acccurate the stellavita is or how it measures but i get below 2 with the rc quite easily

[harsh matrix]

Seti Astro's What's In My Image? script

[slate falcon]

thankuu

[tight lodge]

I gave them .step file and a schematic.

[harsh matrix]

it submits a search radius to SDSS and returns all of the cataloged objects in the radius

doesnt catch everything but it gets most things

ive had resolved objects that are not cataloged before

and that only happens in my RC8 data and nothing else

[harsh matrix]

so even if they did find issues they could resolve them?

[tight lodge]

Before you start yelling I wrote M40x0.75 instead of M48x0.75, I corrected it

[harsh matrix]

close call huh?

[tight lodge]

What issues on a simple part like this😅

[harsh matrix]

well you said you made it in a rush

so i expected if you made a mistake, they might need you to correct it

[tight lodge]

Very, I always double check before committing to something

[harsh matrix]

hell yeah

[harsh matrix]

what did you use to make this btw?

I would like to know if I make another custom part in the future

[tight lodge]

Fusion360

[harsh matrix]

hm

they have a function for that?

[tight lodge]

Fusion has it all, EDA, CAD, Sim, CAM and technical drawing. You can go from start to finish with a project

[tight lodge]

Yep, it literally takes your model and converts it into a schematic

You can not export it as PDF, but you can screenshot it😅

[harsh matrix]

hmmmmmmmmmmmmmmMMMMMMMM

alright ill look into that

that's extremely useful

[tight lodge]

Do you know how to enter the render menu?

In the same tab you have an option for drawing

[slate falcon]

i got a blue object :)

[harsh matrix]

ive never done it so idk

[slate falcon]

(not nova am eepy)

[tight lodge]

It is, especially when you have a nonstandard thread. Like in this case. You don't even need to model it. You just specify it in the schematic

Plus, they don't really like it when you model the threads

[harsh matrix]

oh really?

[tight lodge]

Yeah, it's easier for them to program it than machine it from the model

[harsh matrix]

interesting

good to know

very good to know

[frosty shard]

I strongly suspect you have more than 2 globs in your M104 data. There are 361 within a 7.5' radius of the nucleus

[harsh matrix]

I found 3 and possibly 5

Im lacking integration time

With the moon, theyre completely overpowered

[frosty shard]

oh yeah I forgot about that damn rock

[harsh matrix]

Fr

I want to blow it up

full moon 3 nm narrowband data

1 hour each for H and O

1 hr 10 for H actually

10 minute subs

[frosty shard]

The brightest one, [RZ2004] GCl 274, has a V-band magnitude of 18.65, and is at J2000 RA 12h 40m 02.26s Dec -11° 33' 14.1", which is quite a bit north of the galaxy

[harsh matrix]

interesting

hopefully i didnt crop it out lol

[frosty shard]

Nope I see it in your image

[harsh matrix]

ayo what

[frosty shard]

I should honestly try to observe this one visually

[frosty shard]

I'd probably need the 16" to do it

[harsh matrix]

[harsh matrix]

20 inch

cometary globule

this is not blurx'd

[frosty shard]

@harsh matrix here's all 361 globs I found with identifiers, coordinates, and magnitudes in case the SETI Astro script doesn't catch some

[harsh matrix]

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

my god

i need the Sii filter

this will be peak with Sii

Sii makes it so easy to look deep into the thing

Ha and Oiii have too much overlap to see far in

[frosty shard]

The Swan is so insanely slept on tbh

[harsh matrix]

I learned that when i reprocessed my old frac data

im going to priortize it over Lagoon for the first part of this summer since i havent shot it in 2 years

[frosty shard]

It's just amazing visually too

[harsh matrix]

it's one of the objects ive looked at most

[frosty shard]

I'll always remember seeing it in the 16" with the photographic dual narrowband, and seeing all of the texture in this image with the naked eye

It looks fluffy

[harsh matrix]

oh piss

I think Bx cooked it a little

but DAAAAANG

[frosty shard]

@crisp flower turns out there are ~300 globulars around NGC 5907

[harsh matrix]

holy

[crisp flower]

Goddaaaaamn

Now i regret to Not having Imaged this for longer

[frosty shard]

I'm blown away, this is unbelievable for a galaxy which seems to lack a bulge entirely

[harsh matrix]

UHHHHHH this is decon only

[frosty shard]

Maybe we collab on this instead of M101?

Because then we could get the tidal tails

[slate falcon]

please try rld + wavelets 🥺

[harsh matrix]

told yall

decon is the secret weapon for an RC

[frosty shard]

What's RLD?

[crisp flower]

We can definetely try

[slate falcon]

rirchardson lucy decon

i think thats how you spell it

[crisp flower]

Just need one clear night to get the scope collimated again (hopefully) and im ready to go

[frosty shard]

Oh right

[slate falcon]

or even the name at all

[frosty shard]

I'd love to get sharper IR data

[slate falcon]

get 2 f20 mirrors and seperate them by 1 meter

but them on a massive t bar and but cam at one end

[harsh matrix]

really happy with this ngl

this is so much nicer than the frac data

i want to change the framing i think

to get the back end of the nebula if possible

[crisp flower]

Those Whispy dark nebulae Look soooo good

[harsh matrix]

yeah exactly

can see all of the bok globules too

[slate falcon]

beautiful demo

you just put a losmandiy on the com

and attatch it to ur mount

[harsh matrix]

i think bx is already doing RLD

[slate falcon]

as just the skeleton

[harsh matrix]

that's basically the only option in pix

[slate falcon]

bx is different than rld

[harsh matrix]

BX uses pix's decon function

[slate falcon]

really?

[harsh matrix]

yes

[slate falcon]

huh

maybe thats why i can get rld so close to bxt then

[harsh matrix]

yes

[slate falcon]

just with more noise

[frosty shard]

That goes against everything I've read about BlurX, unless it's been changed recently

[harsh matrix]

that is why

[slate falcon]

same

buut if thats misinfo

[harsh matrix]

im fairly certain BX was trained to use the functions in pixinsight to the best possible extent

[slate falcon]

ig its misinfo?

[frosty shard]

@crisp flower okay these globs are going to be extremely difficult to pick up, I can't even confirm one in my IR data

[crisp flower]

Neither could i in my LRGB- but thats Not too surprising given the Lack of integration

[frosty shard]

They should be brighter in IR, and while I was fighting the full moon I do have 4 hours of int

Still nothing confirmed

[crisp flower]

We can try either way

[frosty shard]

Yeah I figure it's just gonna need a lot more time

I mean there's also the question of the tidal tails

[crisp flower]

Thats be a Bit of a painful Thing to Go for given i can get about 5-6 hrs of Data max in a good night atm

[harsh matrix]

the documentation only says what BX does but not how it does it

I think Russ said it uses the functions in an interview with Adam Block or Bill Blanshan

the documentation does highlight the core difference between classical decon methods and BX as being that BX can avoid oversharpening stars when you want to recover more sharpness in nonstellar objects

[frosty shard]

Yeah, that's why I'm skeptical of any claim made about the tool. This isn't the first contradictory claim I've heard about its operation

My main skepticism comes from the fact that it doesn't recover a PSF (either as a static profile or one changing over the image)

[harsh matrix]

recover as in creates a PSF that can be retrieved in some way?

what if it does but it discards it after use?

it does decon in tiles

so if it is generating a PSF for each tile, that stacks up quickly as far as the number of files that get generated

I think a logical solution would be to discard the PSF after it is used to avoid file bloat

[frosty shard]

I'd want to be able to recover that PSF at least as an option. Either way, they should be relatively small files (I do all my almost all my decon with 25x25 kernels)

Like just 25 pixels across

That's only a few kilobytes in size even when uncompressed

Most imagers can use even smaller kernels

[harsh matrix]

i dunno

it's also likely down to a confidentiality concern since it is a paid product

do any of the other "AI Decon" tools recover a PSF?

especially paid ones?

[slate falcon]

which target?

[frosty shard]

NGC 5907

the one with the explodey star

[slate falcon]

ahh

yea i will have to go for them some day

[frosty shard]

Not that I know of. Usually these tools are not performing actual deconvolution, but are trained on datasets of data before and after deconvolution to approximate it

Which is totally fine and can in theory (and practice) save the user the trouble of finding different parameters

[slate falcon]

yus

[frosty shard]

But I wouldn't call it deconvolution in the strict mathematical sense

[harsh matrix]

I am weak

[slate falcon]

red

[harsh matrix]

okay

[slate falcon]

you should try reveal the blue in the white more

[harsh matrix]

given that information

it is possible to assume BX follows the same rules

[harsh matrix]

id love to but HOO sucks for this reason

enhance that, then you enhance the background blue

then it looks wrong

[plush raptor]

gonna shoot m104 tonight

[slate falcon]

i guess you have to take ir data as a middle man

HIO

[harsh matrix]

no

[frosty shard]

Yeah it's super tricky in HOO. Perhaps a nonlinear color transform could handle it? But I'm not sure how you'd construct a suitable transform to accomplish that

[harsh matrix]

Sii

but not soon

[slate falcon]

nooooooooooooo

ir is cooler

[harsh matrix]

yes

[harsh matrix]

I have an idea

it would not involve pixinsight or siril

[slate falcon]

gimp?

[harsh matrix]

it is my trade secret

[harsh matrix]

affinity photo

[slate falcon]

:)

[frosty shard]

Hey there's always the option of shooting IR data for IHO, ISH, etc.

[slate falcon]

i feel like the ir data was under stretched

[frosty shard]

Potentially. Tbh I like using IR for stars and just letting H/O take care of the nebula.

You can of course experiment with the data yourself: #1472680611964518614

[slate falcon]

why only ir for just the stars?

[harsh matrix]

how bout that

basically just did what i was thinking with curves only

[slate falcon]

im sure you could make the very very core bluer

then you have a transition from red to blue

with a large intermediate white

[harsh matrix]

i did

however

this part likes to go white

[slate falcon]

moaaarrrrr

[harsh matrix]

no matter what

[frosty shard]

I just like the red stars that infrared/narrowband composition provides when you do it wavelength ordered

[harsh matrix]

it's because H-alpha and Oiii have too much overlap in the core

[frosty shard]

it's also tricky to stretch IR and narrowband together

[harsh matrix]

so it because white instead of blue or red

a pain to undo or reverse

[slate falcon]

thats it

im frying your data

i made it green

bet you werent expecting that

[frosty shard]

Perhaps you could try composing the H as #FF0080 and O as #00FF80, then stretching the blue a little harder than usual

or use a CCM to mix the channels post-stretch

[harsh matrix]

that looks awful

see how forcing it made it posterize?

that's why i dont do that

[slate falcon]

it looks like you put in a mask at the core

thats what i thought happened anyways

all blue core lacks the vibe tho

sad

[slate falcon]

when these starvis 3 sensors come out

they state there will be a better adu

[plush raptor]

a few weeks ago

[slate falcon]

like a better one

[plush raptor]

starvis 3 585

mystery nebula

near andromeda

[slate falcon]

starvis 3 533 but with a 585s qe

[slate falcon]

no, thats known

[plush raptor]

what is it

[slate falcon]

its an snr i belive

imx908 doesnt have much released

[harsh matrix]

nope

[slate falcon]

lack of dynamic range?

[frosty shard]

better ADU? meaning a 16 bit sensor? or something else

[slate falcon]

i belive so

the first sensor is only 12 bit

[frosty shard]

Oh right for the 585?

Well here's my take on ADU bit count

It only matters to the point that you can account for the sensor's well depth

[harsh matrix]

probably not

maybe just how i stretched it

i can change that with some layering and masking

[slate falcon]

[frosty shard]

As astrophotographers we have little reason to shoot below unity gain, so as long as your ADU values are able to count all electrons at unity gain, you don't really need more

So like, unless there's a well depth upgrade for the IMX533, you can have a 14 bit sensor and that will be perfectly fine

[slate falcon]

its not another 585

its half the size

[frosty shard]

oh that is miniscule

[slate falcon]

https://www.sony-semicon.com/files/62/flyer_security/IMX908-AQR1_Flyer.pdf

[slate falcon]

look at the pixel size

they really put a lot of faith in optical quality

[frosty shard]

1.45 µm? Yeah I'm operating that thing in bin2, maybe even bin3 lol

Well not that particular sensor because of its size

But if there's a larger version, absolutely

If the read noise per pixel is low that may actually be better than larger pixels for some applications

[slate falcon]

ye

[slate falcon]

it doesnt have an 8bit output anymore

10bit 12bit and 16bit

are the only options for it

i wonder if people are still gunna try use these with 8 bit fits

[mortal vale]

Why do I see so many people image this galaxy recently? Anything interesting happened there or a new find? Supernova?

[frosty shard]

Yes, SN2026kid

[mortal vale]

Oh, sweet, when did it happen?

Oh, even sweeter, I can capture it

I'll see if I can tonight

[sinful sapphire]

What’s the angular size of this galaxy

[frosty shard]

12.7' × 1.4'

[frosty shard]

April 22, I think it's about to hit peak brightness

[mortal vale]

Hell yeah, now that's peak

[gloomy hawk]

whats so special about these telescopes?

[sinful sapphire]

Why they are Ritchey-Chrétiens

[frosty flicker]

they're very nice

[sinful sapphire]

2 mirrors and they inherently correct abberations, to a certain extent.

Meaning you can have a corrected field with only reflective elements.

[frosty flicker]

just have fun collimating

[sinful sapphire]

that’s why I am a Harmer-Wynne and Corrected-Dall-Kirkham enjoyer.

[tight lodge]

And yet, the thread is full with troubles

[sinful sapphire]

GSO Moment, not RC

[tight lodge]

Yeah... 90% of the RCs on the market 😂

[gloomy hawk]

expensive small telescopes?

is this like the Louis Vuitton of telescopes

[tight lodge]

A brand that does the same as its cheaper unbranded counterpart?

[gloomy hawk]

?

[sinful sapphire]

no

Mainly since Louis Vuitton is a brand and not a model

[tight lodge]

A good RCT is like a Toyota corolla. Reliable but slow asf😂

[gloomy hawk]

[sinful sapphire]

Wrong

There’s fast RCs

[tight lodge]

And there are fast toyotas

[bleak solar]

falling down a cliff does not make a car fast

[sinful sapphire]

I suppose

[tight lodge]

You don't have to throw a Supra off a cliff

[bleak solar]

Fair point!

[slate falcon]

8" gso rct

[sinful sapphire]

go to 100um scale, askar style

[slate falcon]

nou

[sinful sapphire]

do it

i want to have it so i can show askar glazers that the RC8 from gso mogs their 2k refractors 🗿

[slate falcon]

@frosty shard should i get a mod to pin the rct stuff

[slate falcon]

not at home

but when i get home i eill

[slate falcon]

even the 76.2mm noot will outperform their frac

im saying that as if it doesnt have λ/8 and λ/10 mirrors

[slate falcon]

@frosty shard should i try make a sorta Fresnel zone plate slit configuration to try make a usable image with my 585

[frosty shard]

I'd suggest making a single post with all relevant diagrams arranged if possible

[frosty shard]

Hell yeah (but I have no idea what that is)

wait this is actually really interesting

[slate falcon]

fr

[slate falcon]

i should yeah

[frosty shard]

This might be a better option: https://en.wikipedia.org/wiki/Photon_sieve

[slate falcon]

negative zoneplate vibes

ill try it when i get home

[slate falcon]

@frosty shard actually quite high res image trhough an eyepeice

[slate falcon]

pinhole right sieve left

[slate falcon]

i messed up some dots

it shortens the fl a lot

i couldnt get the sive to focus at the same distance

i made a better sieve

2 same size central holes

tried to get the fl the same too

[harsh matrix]

That explains the corners with my 571

Although I think theyre slightly better corrected than that.

[slate falcon]

i have to refocus buut i forgot to in that image

[harsh matrix]

💀

my M104 looks insane on the phone

im happy i went against all conventional wisdom for that photo

it's quite nice

[harsh matrix]

I don't do selective masking like this btw

that's something I did in the early days and then stopped doing because i never liked how it looked

[slate falcon]

isee

[harsh matrix]

and holy balls

I see clear nights near the full moon at the dark sky site

which luckily didnt get hit by a tornado despite it being in the direct path of what appeared to be a tornadic supercell

I need to go request those days off so if it plays out, i can go

[slate falcon]

oh yea, i also now have this pvc abomination

it has 3 sets of doublet lenses in a sorta weird config

[slate falcon]

how is your process goin btw

[harsh matrix]

not messing with it atm

i have other stuff to take care of and I stopped yesterday to play some games with the boys

[slate falcon]

[mortal vale]

Hey, check this out..

I got it :)

Just need to add more than half an hour of data

How much will the peak last?

So I know I don't just keep adding data even when it's getting fainter

Don't wanna lower the signal

[frosty shard]

Not entirely sure, actually I'm not sure where the best light curve data source is
https://www.wis-tns.org/object/2026kid

this one is empty

[mortal vale]

It's my first ever, that's crazy, holy I'm so happy

My shooting scene btw

[harsh matrix]

@frosty shard just registered for classes at university

going to become a cybersecurity major with some Python experience

im hyped since Python can translate to astro as well

[frosty shard]

I defend my thesis on May 29, so you're gonna take my place as a student 🫡

[harsh matrix]

Okay wow, no pressure.

[harsh matrix]

the core is very blue

it's just too bright to tell

and this screenshot really doesnt do it justice

there

i dont like this though

im going to split it and then take it into affinity photo

[frosty flicker]

damn omega neb is already back in season

[harsh matrix]

holy

3nm is on another level

jeez

those were a good choice

im glad

im so used to halos that not having any feels really weird

the core is being annoying but it feels dramatic nonetheless

mood

FAAAARRRR better control in Affinity

and no posterizing happening unlike in Pix

this is why I loved my layer based editors

[plush raptor]

newts rule

[frosty shard]

How about both you and @sinful sapphire get out

[plush raptor]

but I got mono so it cancels out

[haughty steppe]

Pretty good for 22x15min subs with the 3.5nm ha filter.

[plush raptor]

holy crab

[slate falcon]

it looks a lot bluer now ive turned the blue light filter off

(for some reason it hurts my eyes to look at phones without it)

[sinful sapphire]

Being a CDK and HW enjoyer doesn’t mean I don’t love Ritchey-Chrétiens. Thinking about upgrading to an EQ6 and popping a carbon truss rc10

[tight lodge]

Are you threatening us with buying gear again?

[bleak solar]

Hey guys, quick question. I am printing out a longer baffel extension. Do i need to remove the primary mirror in order to install it properly and how can I do that?

[sinful sapphire]

This is why you don’t have more money for Astro, you never think about buying stuff long enough

think about it hard enough and a good used deal appears

Think how rich you would be

[tight lodge]

Nooo, it's because I have a family to take care and prioritize over this hobby

[sinful sapphire]

uhh then…

uhhh

shutup

[harsh matrix]

yes

around the back of the tube, there are screws that hold the primary mirror cell onto the tube

you need to remove those and the ones hiding under the dovetails

once you remove all of them, the cell should come free

I always mark the position with a piece of tape and I use a sharpie to mark the rough center of the tape in a line in the direction of the rest of the tube like a hash mark, and then i cut the tape with my finger nail or scissors, and then do all of the above

the tape lets you put the primary mirror cell back into the exact position it was in originally

the RC's is so much sharper it isn't funny

the stars are so small that some of them arent visible unless you look closer

that's RC8 vs 102 mm frac

both bx'd and noise reduced for a fair comparison

to show what each scope is/was capable of at their best

the frac is sharpened a lot and even parts of that image still look blurry compared to the slightly oversampled RC image

[bleak solar]

So I won’t need to worry about re doing the collimation?

[harsh matrix]

you might have to

but not to a large extent

it would be small adjustments at most if it gets out

then do i even need to speak?

there's more thin filaments visible in the dark neb too

oh my...

kicking a dead horse...

this is when it is no longer fair

but even then you can see the difference Sii would make

how the red can punch through the Oiii so much better than standard HOO allows

[tight lodge]

Why do you have a 102mm fr*c?

[frosty shard]

more like curbstomping an entire stable, jeez

[sinful sapphire]

🗣️

[frosty flicker]

you want an 8" frac?https://app.astrobin.com/equipment/marketplace/listing/7vqgbe/tec-apo200fl-chroma-50mm-round-unmounted-3nm-ha-chroma-50mm-round-unmounted-3nm-oiii-10micron-gm2000-hps-ii-optec-ftx40-focus-motor-for-feathertouch-35-focuser-pegasus-astro-ultimate-powerbox-v3-chroma-50mm-round-unmounted-3nm-sii-astromi-mgpbox-feathertouch-35-focuser-moravian-instruments-c3-61000-pro-starlight-express-lodestar-pro-mono-guide-camera-chroma-50mm-round-unmounted-lrgb-set-intel-nuc-12-core-i7-4tb-sdd-32gb-computer

full setup at SRO

[tight lodge]

My 5" newt has tighter stars than that thing. And is a fraction of the price

[frosty flicker]

but has less light collection surface area

[tight lodge]

f/5 vs f/8.

[frosty flicker]

more apperture

[frosty shard]

Yeah but refr*ction is happening so your argument is invalid

But wait

That's also happening with the Newtonian's coma corrector

So the glorious Ritchey–Chrétien wins every time

[tight lodge]

Which needs corrector to be the glorious one

[frosty shard]

Nope. Coma free. Distortion free. No corrector needed.

[tight lodge]

The way you try to dodge astigmatism

[tight lodge]

Also, you use filters. Refraction happens in the filter

[frosty shard]

I swear to god someday I'm going to solve this problem and have a refraction-free setup

[crisp flower]

I wanted to say "Coat the mirror and have a scope for each Filter" but then refraction Happens at the mirror wouldnt it?

[frosty shard]

Well yeah if we're being really technical every mirror with an overcoat is refracting

Huh, maybe James Webb isn't lol

Idk if you need to overcoat gold

[crisp flower]

I dont think ud have to overcoat Aluminium as Well but it would need to be recoated due to Oxidation i think?

[frosty shard]

Usually there's a layer of silicon monoxide on GSO mirrors

Do you know about aluminum's high reactivity?

[slate falcon]

sell family, hobby harder

[crisp flower]

I obviously didnt Take that into account

[tight lodge]

I already solved that issue

[slate falcon]

this is why gold murrors are best

[frosty shard]

Actually idk because this is something I know very well as a chemist (aluminum passivates in air to form a thin oxide layer but does not corrode further at an appreciable rate) but I have a very poor sense of how well that is known generally

Aluminum used to be more expensive than gold because you had to react dry aluminum chloride with potassium metal to get aluminum metal

and potassium was neither cheap nor easy to work with (nowadays it is much cheaper)

then some dudes named Hall and Héroult thought "what if, instead of trying to smelt aluminum or react it with a more reactive metal, we electrocute it into submission"

and thus the Hall–Héroult process was invented

[crisp flower]

Interesting

[frosty shard]

Yeah we're kinda lucky that aluminum, despite being very reactive, rapidly isolates itself from things that corrode it

But unfortunately this can be a problem for aluminum mirror coatings

Because the oxidation can continue at an extremely slow rate

For a solid block of aluminum this is basically irrelevant

For a thin aluminum mirror coating it is not

I think the reason they use silicon monoxide is because it's actually more reactive than aluminum in oxygen, and converts to more stable silicon dioxide rather than penetrating into the metal

[crisp flower]

So basically rather Go for a gold mirror

[frosty shard]

If you don't like blue light

maybe they should make telescopes that use gold mirrors as "low blue light technology" so it doesn't mess with your sleep schedule

[crisp flower]

If i want to Focus on nir, it would be pretty perfect i guess

[frosty shard]

Yeah gold's excellent in NIR

Aluminum is superior to even silver in UV I think

[crisp flower]

Thats Something i wouldnt have guessed tbh

[frosty shard]

from Edmund Optics

wow that did not render right

Protected silver is probably the best choice for an amateur astronomer

since UV isn't really that feasible overall

[crisp flower]

This was painful to try to read xD

[frosty shard]

https://www.edmundoptics.com/knowledge-center/application-notes/optics/metallic-mirror-coatings/

[crisp flower]

Ive Seen this one a while ago
So freakin tempting

[sinful sapphire]

refraction happens in the air too.

[slate falcon]

woa

[slate falcon]

yes

gold does need it badly

but for protection

in the factory and stuff

[harsh matrix]

@slate falcon how's this

depending on monitor quality this is either very blue or very white

depends on dynamic range and color representation of the monitor itself

[slate falcon]

what if its red white green

[harsh matrix]

[harsh matrix]

are you looking at the monitor at an angle?

[slate falcon]

my monitor looks same from all angles

[harsh matrix]

one of mine doesnt look the same from all angles

[slate falcon]

ah i had night light on again

[harsh matrix]

🗿

[slate falcon]

its a more subtle green

its mostly white tho

[harsh matrix]

it is more blue than in pix though

i couldnt get it to be quite this potent

[slate falcon]

on my phone is cyan

[harsh matrix]

im not going to force it because it will look unnatural

ye

should be cyan

[slate falcon]

ohh omay

im calling cyan green

(other then when night light is on then its actually green)

[harsh matrix]

when i put a real image in here and not a screenshot it will likely be a lot more colorful

that screenshot is lacking color on my phone

[quartz meadow]

color calibrate your phone

[harsh matrix]

png is too big to post

[harsh matrix]

not sure that's possible but screenshots wont be color accurate no matter what, so that would accomplish nothing

now im seeing a hint of green

[frosty shard]

@harsh matrix collimating visually right now, and I'm realizing that for making the final adjustment to null coma, the eyepiece is more sensitive than a camera

I could see coma my camera couldn't

[harsh matrix]

interesting

[frosty shard]

I can see the Poisson spot dead center all the way through focus now

I could not before

[harsh matrix]

interesting

the only problem i can see with that though is identifying the direction the coma is pointing in if the eyepiece isn't of great quality, if you are using a diagonal, or if you are using a compression fit to hold the eyepiece onto the system

[frosty shard]

Yeah, the eyepiece uses a compression ring, so I'm only evaluating this once I actually image again

But there was no clear indication of spherical aberration

Unfortunately the post office or building management appears to have lost the Ronchi eyepiece I ordered

so I don't have an alternative method to check for that outside of a star test

But it looked perfectly symmetrical in and out of focus

My main limitation is that I can only take my RC up to 203x with my shortest eyepiece (8 mm)

[harsh matrix]

that is lame af

[frosty shard]

I'm more willing to blame the building management for this, because I've been noticing that there are like no packages being delivered in the mail room and now I think there has been a problem for some time

Apparently nobody there was aware

[harsh matrix]

@tight lodge are you cnc'ing or custom making pcb's for your radio dish project?

[tight lodge]

In most cases I can buy the more complex electronics, like filters ir LNAs, but when it comes to feeds, then I will most likely make custom feeds out of PCBs. The most recent one is more of an adapter than an actual antenna. But I did CNC machined a PCB patch antenna before and it was quite successful. Machining PCB is a bit hard because if your spindle can't spin fast enough, you have to use some kind of lubricant

[harsh matrix]

https://www.youtube.com/watch?v=P7Dek2pXUHs

I stumbled upon this guy a little while ago and it is making me very tempted to try some radio even though i dont have space for such a thing in the yard

[harsh matrix]

[tight lodge]

Ah, I know this dude. He is mostly skimming the surface to radio astronomy. Detecting geosats is not necessarily radioastro

[harsh matrix]

he's building up to do some 21 cm line stuff

i want to see what he finds when he finally gets there

[tight lodge]

I can show you.
He'll fund this😅

That smooth bump in power is the neutral hydrogen line

[harsh matrix]

hell yeah

mostly curious to see how far he goes

to see if he will attempt to produce an image or not

[harsh matrix]

anyway, just because im curious, do radio dishes care much for the material they are made out of?

[tight lodge]

Anything RF reflective. You usually tune it afterwards. If you go for a mesh antenna, you want the mesh to be λ/10 maximum. Finer mesh will result in a better reflectivity

[harsh matrix]

that's not terribly specific since I dont know what constitutes as RF reflective

plastic?

metal?

[tight lodge]

Metal

[harsh matrix]

hmmmm

[tight lodge]

It's pretty much anything that is electrically conductive😅

[harsh matrix]

That's a lot more helpful

I know what that means

So no aluminum? 🗿

[tight lodge]

Aluminium is more than fine

[sinful sapphire]

@frosty shard

LOic is making Ritchey-Chrétiens, meaning GSO has actual competition now

[tight lodge]

People have made pyramidal horn antennas out of cardboard and aluminium foil😅
You can make an antenna out of anything if you have the tools to tune it

The tool is called a VNA (Vector Network Analyzer) an absolute indispensable tool

[tight lodge]

Also, the PCBs I designed should arrive tomorrow, so this weekend I will assemble a dipole and test it. If it behaves well, I will share grbl files

[frosty shard]

Leaving this here for posterity

[slate falcon]

pickle will you ever make a microwave scope

[tight lodge]

Gimme the budget for some high frequency clocks, and you got it

[slate falcon]

how much would that cost

now im curios of the price

[tight lodge]

But technically, I already did 1.4GHz is in the microwave spectrum😅

[slate falcon]

whats the wavelength

[tight lodge]

21cm

Or about yay big

[slate falcon]

[tight lodge]

Or yay big

Or yay big🤣

[slate falcon]

oh yea, have you got the functioning one yet

[tight lodge]

Yup

[slate falcon]

faancy

[tight lodge]

Tomorrow I should get these

[slate falcon]

[tight lodge]

It's a tough hobby. It takes a lot if time, planning, designing, manufacturing and tons of meth

*Math

[slate falcon]

meth for increased math performance

[tight lodge]

I meant to say math... autocorector decided that meth fits the context of the sentence more

[slate falcon]

[frosty shard]

Are they all truss tube scopes?

I think I'd prefer a solid tube but I haven't really looked into the potential issues with light shielding much; it may be a non-issue

[sinful sapphire]

yes

but they only have 12" and 16" atm

[frosty shard]

Are these GSO mirrors or is someone else making them?

At least for RCs it seems like GSO can get the figuring right

[sinful sapphire]

GSO isnt behind them

a chinese company named starhop is listed as the company over LOic

Starhop and Lichtenknecker formed LOic together so

[frosty shard]

I would be very interested to see how good they are at making hyperbolic mirrors

Hopefully it's an improvement

[sinful sapphire]

hyperbolic mirrors arent rocket science

you just keep parabolising a parabola

[frosty shard]

That's true, but turned down edge is still a thing

[sinful sapphire]

true

[frosty shard]

I found a link some time ago to a test of the wavefront of a 10" GSO RC and it was actually really good

I've heard this about GSO mirrors numerous times in the past

but I didn't have any numbers to back it

https://interferometer-tests.blogspot.com/2013/06/2542000-10-ritchey-chretien-gso.html

However, I don't think this counts as a complete evaluation, because you'd want to verify that there is both no spherical aberration and no third order coma across the field

An improperly made RC will not null them at the same focal length

[slate falcon]

cirblce

[tight lodge]

@frosty shard I have a question that is kinda bugging me and I can't wrap my head around it at this moment. Why a parabolic mirror reaches focus at 2r?
Like my 650mm fl mirror, reaches focus at 1300mm.
That's something I noticed with the interferometer

[frosty shard]

What is it focusing on?

Something at infinity?

[tight lodge]

It's focusing on the interferometer
Here's the diagram. Basically the focus point of the return path is somewhere past the beam splitter

The reason why lasers are used is because they kinda behave like an extremely far point source of light. So technically, the interferometer is focused at infinity

But... why 2r?😭

[frosty shard]

Well if the effective focal length is 2x, then that implies that you're actually focused at the curvature radius

[tight lodge]

Yes, because otherwise it doesn't work. The mirror goes out of focus.

[tight lodge]

I wonder. If I use 2 lasers. One on the interferometer and one that appears at infinity, can I see both focal points at once?

[slate falcon]

better tha

[tight lodge]

Huh?

[slate falcon]

idk

was gunna say a joke

https://drive.google.com/drive/folders/1CtOEZKz_IjJ7FyBIbFgj58dMvg9phqGQ?usp=sharing

@frosty shard

heres how the spots look when the secondary is rotated 90 deg

[slate falcon]

@frosty shard guess what is causing this funky ab

[crisp flower]

I think this need secondary adjustments?

[sinful sapphire]

slew to a bright star and do the star test there

[crisp flower]

I think the mirror distancing might need some tweaks

@sinful sapphire what do u think?

[sinful sapphire]

Is this intra or extrafocal?

[crisp flower]

I have No Idea what that means

[sinful sapphire]

if youre intrafocal, the sensor is too far inside focusing tube. if youre extrafocal the sensor is too far outside the focusing tube

[crisp flower]

Aaaaaaah give a sec

It was intrafocal

[sinful sapphire]

do two shots, one intrafocal and one extrafocal, ideally by the same amount

[tight lodge]

Duuuh that's what happens when you go extra or intra focal💀

[sinful sapphire]

why you shooting the guy explaining it

https://cdn.discordapp.com/attachments/920016996752564286/1251695052980359209/convert.gif

[tight lodge]

I just find it funny the way you explained it😂

[sinful sapphire]

how else should i explain it

https://tenor.com/view/ishowspeed-ishowspeed-angry-ishowspeed-overwhelmed-i-show-speed-ishowspeed-early-stream-gif-10270539420371864887

[crisp flower]

Extrafocal

[sinful sapphire]

by the same amount yes?

[crisp flower]

Fk im Not Sure

Let me try that again lol

[sinful sapphire]

best way is to use a bright star

fk it maybe even jupiter

actually maybe not because of hte focal length lol

[crisp flower]

Does exposure length Matter?

[sinful sapphire]

so like arcturus

[sinful sapphire]

id want to see the patterns like this in the star

[tight lodge]

Inny blurry, outy softy

[sinful sapphire]

https://cdn.discordapp.com/attachments/1248873743116140586/1273203966024487003/ezgif-2-db49a54415.gif

[crisp flower]

I think i did it wrong

[sinful sapphire]

This tells me enough honestly

spherical aberration^2

your mirrors arent spaced properly so you are correct

and theyre quite off it seems

[sinful sapphire]

Yeah okay youre undercorrected

meaning you need to space the mirrors i believe

[slate falcon]

https://youtu.be/_j29mhr-ITQ

i didnt mean to send that here

ah well

[slate falcon]

fokal

[slate falcon]

gimme 5 rings on each

[slate falcon]

you should probably explain to them in detail so they wont need help in the futre

[waxen mountain]

Noice vid

[slate falcon]

gud music

[waxen mountain]

https://tenor.com/view/yeet-gif-2006776531331284522

[sinful sapphire]

Right

[crisp flower]

Right so which direction do i want to adjust the spacing to?😅

[sinful sapphire]

So because of the central obstruction being bigger in intrafocal (and better defined) than in extrafocal, you are undercorrected.

If you were overcorrected it’d be the other way around

To fix undercorrection I believe you need to space apart the mirrors. @slate falcon fact check me on this

[slate falcon]

you should have to yea

[sinful sapphire]

Yeah

[slate falcon]

ill try figure if you need to move it in out out

spherical ab gets worse the furthe away it is

[sinful sapphire]

Ok then I mixed it up, closer together it is

Woopsies

[slate falcon]

i need to condense it into a lovely chart

i may do that in a bit

by a bit i mean like right now

[slate falcon]

is this helpful at all

[slate falcon]

move the secondary baareely closer

[crisp flower]

Will do next opportunity i get

My night Just got ended by clouds

[slate falcon]

[crisp flower]

Me when the Clouds rolled in

[digital nexus]

what eyepiece

[plush raptor]

i feel like collimation is one of 2 reasons that newts of the same apeture of fracs are not as sharp

[frosty shard]

Baader Hyperion 8 mm

[frosty shard]

Well you'd have the same problem with any optical system that's not critically sampled I think

[frosty shard]

@harsh matrix I think finishing collimation visually was the move

[harsh matrix]

fr?

[frosty shard]

The seeing is terrible, my scope is still cooling, and my HFRs are better than ever

[harsh matrix]

how better

[frosty shard]

We'll find out once I get back to my scope

[frosty shard]

Not a huge improvement, but it does seem better than before. I consistently got HFRs at ~4.0 for all autofocus runs

But I'm not entirely sure just because the seeing was garbage

I decided to recreate my 9 minutes on M16 from last year (left), new data is on the right

both are only stretched

but man, you can see the difference in the stars' sharpness

[quartz meadow]

I see it, yeah

[slate falcon]

did you only change collimation?

[plush raptor]

tea, I might get an oouk scope

[harsh matrix]

@frosty shard I wont get much time on the Antennae galaxies from the dark sky site

it's already too late into the season

if i go for 2 nights ill get about 4 hours total

it will be an image about on par with what id be able to get at home after about 20 hours but im not sure the tidal tails will be visible and i doubt the data will be all that sharp

[stiff mason]

So i had a genuine question what is stopping someone from using their sensor to measure wavefront error and using that data to deconvolute their images far better than anything blurx could achieve since you aren't guessing the PSF you physically know it

[slate falcon]

nothing

you should do it

[stiff mason]

Can't no mount 😪

Also i would need a beam splitter

Specifically one that reflects infrared

[slate falcon]

why not put an ir filter before the splitter?

[stiff mason]

I need the ir so i can use the visible light for my main image and infrared to measure the psf so i dont waste light

[slate falcon]

ahhh

thats painful to do

[stiff mason]

Also the psf needs to be measured from the same optical tube looking through the same turbulent cell

[stiff mason]

It's basically just an angled ir cut filter

[slate falcon]

weird stuff hapens when you angle ir cut

or any filter

which is why it painful

[stiff mason]

Ik band pass shift but this is specially made for it

[slate falcon]

have you found one?

[stiff mason]

It's actually more similar to a mirror that is transparent to visible and is reflective in ir

Also no I'm told it exists

But i have to see if i can find one

[slate falcon]

i got that dw

[slate falcon]

could you get 9 of these and make a 3x3 sensor?

[tight lodge]

Yes, they are called phased array antennas

[slate falcon]

i am no radioknower

[slate falcon]

how common are they in the ametur universe?

[bleak solar]

So many adapters…

[harsh matrix]

real

make sure you either tape over these or keep the screws there

this leaks light

[slate falcon]

its too well corrected