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Struggling with Post Processing, any Help appreciated


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On 02/03/2021 at 12:13, Newforestgimp said:

doing things correctly

 

ss1.thumb.jpg.8668277c31bb063d190320ee39e97ff4.jpg

Hi

The acquisition looks great. There's some lovely detail hiding there:)

Here is the luminance of the stack from the light and bias frames. Best not using dark frames with a 1300d. 

Could you post -a link to- the flat frames too? They would allow us to lose the dust, the vignetting and enable much easier processing.

Cheers

 

Edited by alacant
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The winner of the last imaging process challenge (super image) used PS and shared the steps they had used for a particularly tricky bit. Affinity, GIMP, Paintshop Pro and PS I think are pretty similar

There are three links above.

I am relatively new to astrophotography too.  But i thought i would give this a go as i see it as practice! 😀 I noticed that you do not have any flats.  This would address the dust bunnies/motes t

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53 minutes ago, alacant said:

 

ss1.thumb.jpg.8668277c31bb063d190320ee39e97ff4.jpg

Hi

The acquisition looks great. There's some lovely detail hiding there:)

Here is the luminance of the stack from the light and bias frames. Best not using dark frames with a 1300d. 

Could you post -a link to- the flat frames too? They would allow us to lose the dust, the vignetting and enable much easier processing.

Cheers

 

I don't think OP has flats alacant.

Please correct me if I am talking nonsense! 

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The winner of the last imaging process challenge (super image) used PS and shared the steps they had used for a particularly tricky bit. Affinity, GIMP, Paintshop Pro and PS I think are pretty similar and there are some processing functions in SIRI which are useful. Processing gets easier the more it's done. Unfortunately not all videos on YT are great. Keep at it, it's a learning curve and don't throw old data away as I often revisit old data if I pick up a new skill to see if I can improve an old data process.

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sorry for delay replying I’ve had my head in Astro Pixel Processor demo.

sorry no flats, I’ve struggled to capture flats that don’t do more harm than good but I have ordered a light panel as suggested in a previous reply to hopefully remedy that. Do they make processing an easier experience ?

interested to hear the rationale for not using dark files ? 

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2 hours ago, happy-kat said:

The winner of the last imaging process challenge (super image) used PS and shared the steps they had used for a particularly tricky bit. Affinity, GIMP, Paintshop Pro and PS I think are pretty similar and there are some processing functions in SIRI which are useful. Processing gets easier the more it's done. Unfortunately not all videos on YT are great. Keep at it, it's a learning curve and don't throw old data away as I often revisit old data if I pick up a new skill to see if I can improve an old data process.

I’m actually chugging away on my first Andromeda attempt from few months back, will be interesting to see if I make a better job of it.

 

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Flats with Dark Flats really help. Darks with a DSLR can just add noise. Can always experiment with your DSLR darks when stacking.

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There is something in there but I struggled to bring it out.

image.thumb.png.9b3d79a73bff0feaff75d1a83d89c64c.png

I've removed the stars and denoised it. The dust bunnies can be partially removed in post as I have done here but you can lose data of course. I can see some glimmer of red in the image so I'm guessing that this camera hasn't been astro modded at all?

Here I have run Gradient Exterminator and brought up the reds selectively

image.thumb.png.f41687050d5a40b84842c438f90f0a5f.png

I then used some masking to bring up the detail and added the stars back after doing a star reduction

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Quite rough processing on my side, a lot of dust moats and quite blurry. But it shows it can be done with a little work. The colour detail is quite sparse hence the fuzzyness however it has caught some of the shape of the Rosette. I used a combination of PixInsight, PhotoshopCC 2021 and Topaz Denoise AI BTW..

You are on the right tracks with going forward with the purchase of a light flats panel as that will minimize dust bunnies and vignetting.

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50 minutes ago, TerryMcK said:

You are on the right tracks with going forward with the purchase of a light flats panel as that will minimize dust bunnies and vignetting

Perfect, and thank you for taking time out to have a go, it has given me some confidence I’m on the right track and need to get better quality data capture IN, easier better processing OUT. What I’m hoping is that given decent data what I’m doing in Gimp is actually ok. I have had a few successes with much brighter targets.

as for Blurred I’m for the first time in my life, being just the right side of 50, I find my 20/20 vision is letting go at a rapid pace and focussing has become a “challenge” shall we say, my brain gives up, is it focussed ? It is focussed in my glasses ? But not when I take them off ? Is it focussed just for me and a mess for everybody else 😂 so much so I’m at that crossroads of what gear to get next and should it be an auto-focuser 😂 instead of Astro camera.

Yes star masks !! That is something I need to learn properly, I’ve been trying reducing stars by using ‘colour select - grow - feather- value propagate’ in Gimp, it works to a degree but must learn proper masking to remove them as you have done.

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Not sure if you have one but a Bahtinov mask will get you in focus really easily. It takes all the guess work out of it.

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13 hours ago, Newforestgimp said:

Do they make processing an easier experience

Yes. Flat frames really aren't optional. You're making life a lot more difficult without.

13 hours ago, Newforestgimp said:

rationale for not using dark files

Unless you've the 12mp sensor or (one which is at least ten years) older and unless you take them at the same temperature as the light frames (with an unmodified dslr you can't) or have a decent dark optimistaion algorithm (e.g. the one in Siril, but even then...), they will add more artefacts. Much better to use Light, bias and flat frames only, dither between the light frames and stack using a clipping algorithm.

Cheers and HTH

 

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22 minutes ago, TerryMcK said:

Not sure if you have one but a Bahtinov mask will get you in focus really easily. It takes all the guess work out of it.

I have the built in bhatinov on the WO ZS61, and I’ve been using Remote Desktop into APT live view on laptop from my phone for focusing at the scope, maybe I should try using a tablet to give myself a bigger screen. Also I’m not sure on the backfocus, I’m using an adjustable William optics flat 61a but with addition of 2” light pollution filter, I’m actually considering removing the filter as it was only a cheap one to experiment with. WO recommend 12.9mm on the flattener adjuster for DSLR  if memory serves and somebody on here recommend bumping that up to 13.7 with the filter in place which I did ?

hopefully the light panel will arrive soon...

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17 minutes ago, johnst said:

the price of one

There are other methods for producing flat frames such as using a t-shirt over the telescope aperture and e.g. pointing at the sky, but they're a bit hit and miss. 

A light panel costs less than €10 and makes the production of flat frames consistent. I'd recommend one.

HTH

 

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I might give it a go later as well. 

If you are willing to invest a bit into processing software i would highly recommend Pixinsight. It takes a bit time to get used to but there are lots of great tutorials out there and it is amazing what you can do with it once you get the hang.

For taking flats i currently strap a white shirt over the front of the scope and hold my phone with completly white screen aproxx 10 centimeters in front of it. works pretty well for the moment and defenetly better then no flats :)

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19 hours ago, LordLoki said:

I might give it a go later as well. 

If you are willing to invest a bit into processing software i would highly recommend Pixinsight. It takes a bit time to get used to but there are lots of great tutorials out there and it is amazing what you can do with it once you get the hang.

For taking flats i currently strap a white shirt over the front of the scope and hold my phone with completly white screen aproxx 10 centimeters in front of it. works pretty well for the moment and defenetly better then no flats :)

Thank you, I look forward to the output with interest....
My Light panel has arrived since posting this, only used once so trying to figure out the best exposure settings as AV mode on the canon seems to be producing a horizontal dark band at the top of the frame. I think Pixinsight is probably the only one i havent tried 🙂 & not sure i want to I didnt want to enjoy it and leave myself trapped in spending a lot of money, Photoshop is annoying as they want subscription and the demo version is so short. I'm currently trying Afinity Photo demo and APP.

Processing Software tried so far...
DSS - No Fuss Works Well - Keeper
SIRIL - Bit of upfront organising but stacking is excellent via scripts, post processing less so. - Keeper
SEQUATOR - SO FAST !!! - keeper
GIMP - Tricky but fully featured and free - keeper (because its free)
Astro Pixel Processor - Superb, lengthy but simple stack procedure, some good tools for basic post processing. - keeper
NEBULOSITY - Very good but too lengthy for me - wont purchase
STARTOOLS - Never got anything decent out of it - wont purchase
AFINITY PHOTO - Too early to tell but looks promising - cheap enough to buy anyway
 

Any others I should try ? 😂

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On 03/03/2021 at 21:24, happy-kat said:

Flats with Dark Flats really help. Darks with a DSLR can just add noise. Can always experiment with your DSLR darks when stacking.

I have just done a side by side comparison of using darks with my modified Canon 200d.  I took the usual lights, darks, bias and flats of the heart and soul nebula. I then stacked the lights, darks bias and flats in DSS. I then stacked just the lights, bias and flats using the exact same settings in DSS. The two TIFF files were loaded into GIMP and processed side by side using the exact same settings and method work flow. 

The result? Well from my eyes I see no difference. When zoomed in to maximum I see a very small pixel change when switching between the two processed images.

My conclusion? I will do this test a couple of more times but for my camera I see no point in taking darks. The added hours to an imaging session are just not worth it in my case.

Edited by Chefgage
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58 minutes ago, Chefgage said:

very small pixel change

Hi

Not so much the individual pixels or even clumps of noise, rather the pattern left -quite often bands where many pixels are set across the whole frame- by non optimised dark frames. 

On the older 12mp sensor however the only way we've found to remove the banding pattern is via a master dark frame calibrated using Siril's dark optimisation. Newer sensors don't need this. Your 200p is as clean as they get.

Cheers

Edited by alacant
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