Image Pre & Post Processing Software Recommendations

[Newforestgimp]

Good Morning SGL,

I'm very new to AP and currently evaluating different image processing software to see which one is the one or combination to use for me. At the same time for a friend who simply doesn't want to get bogged down in endless hours of tweaking.

So far I've been experimenting with...
1) Deep Sky Stacker, followed by GIMP - Very Manual lots of complex settings and jargon in DSS, Steep learning Curve with gimp
2) SIRIL standalone and also followed by GIMP - Upfront file planning required but once done very easy to use, image processing a bit confusing.
3) Nebulosity 4 standalone, (not yet tried outputting to GIMP) - stacking and bias/flats/darks  pre-processing a bit complex with lots of options, seemed to produce a finer detailed final stacked image, but as yet not managed great stretching (could be my data isnt sufficient yet for this tool), colour seem muted but more natural.

Just wondering what other suggestions there are, and what people's experiences are of the onboard post processing. Ideally a one stop simple package that produces consistent stacking results with enough post processing ability to give a satisfactory image without necessarily the need to go into GIMP/Photoshop and best of all FREE !

As a complete noob I'm assuming there might be an astro specific program that has a series of automatic features or scripts and gives a reasonable result without going to the professional levels of minute tweaking ? I'm more content to fiddle with GIMP but I know my friend wont, he simply wants to see what he has captured of a night without spending hours at a laptop.

Thanks in Advance

Andy H

[PeterCPC]

Not free but I can recommend AstroPixel Processor and Affinity Photo.

[fifeskies]

GIMP is a complex bit of software if you want to drill down into all the bells and whistles it offers.

 

That said simply using the Colours-Levels and the Colours Curves settings are often enough to change a disappointingly blank image into a useful one.

 

Its very good for free software , and once you have done it a few times its very easy to do the basics in just 5 or 10 minutes , you can of course spend much longer to get the very best out of the image but I reckon you are 90% of the way there in 5 minutes so ideal to see what you have captured.

Help your friend through the simple 2 steps a few times (Levels adjust and Curves adjust) so they feel confident to do it on their own.

Its like many things , daunting at first but once you get familiar you barely need to think about it.

[Newforestgimp]

16 minutes ago, fifeskies said:

GIMP is a complex bit of software if you want to drill down into all the bells and whistles it offers.

 

That said simply using the Colours-Levels and the Colours Curves settings are often enough to change a disappointingly blank image into a useful one.

 

Its very good for free software , and once you have done it a few times its very easy to do the basics in just 5 or 10 minutes , you can of course spend much longer to get the very best out of the image but I reckon you are 90% of the way there in 5 minutes so ideal to see what you have captured.

Help your friend through the simple 2 steps a few times (Levels adjust and Curves adjust) so they feel confident to do it on their own.

Its like many things , daunting at first but once you get familiar you barely need to think about it.

Thanks,

Yes, I'm getting a bit better with GIMP, trying to narrow down a few steps and processes to have a 'go to' workflow that works 90% of the time. Without too much time on Nebulosity so far SIRIL has been the most straightforward for me followed by DSS. Ill try APP when the weather improves as its only a 30 day trial.

[vlaiv]

12 minutes ago, Newforestgimp said:

Yes, I'm getting a bit better with GIMP, trying to narrow down a few steps and processes to have a 'go to' workflow that works 90% of the time

Here is workflow in Gimp that works 99% of time , but you need to have properly prepared data for it.

Data needs to be still linear, but wiped (background and gradients removed) and color calibrated (often referred to as color balanced).

There is only one step of difference between LRGB and OSC data in this workflow - way how Luminance is obtained. With LRGB - you already have it, but with OSC you need to extract it. I'll list OSC workflow and lum extraction step can be skipped for LRGB data (here you replace it with RGB compose to combine R, G and B data into color image).

- Take your RGB image and decompose it into LAB model Color / Components / Decompose (select lab, and decompose into images not layers), discard A and B

- With L as Luminance do Color / Levels and bring top level back down all the way until you see that your target is starting to saturate. Back off a bit so that you no longer have saturation but brightest parts are bright

- Do another round of Color / Levels - this time use middle slider and bring it down until you start to see faintest bits of target. This step is critical as it will show too much noise if you go to far and often needs to be repeated until you find good stretch value (undo next and this step and then redo until you are happy with results). Background will turn bright here but we will deal with it in next step

- Do third round of Color / Levels - this time using lowest (left) slider and bring it right up the foot of histogram. Make sure you don't eat into histogram as that will clip the black point and you don't want that. When you do this - if there is too much noise visible - undo this and previous step and go back to middle slider - this time not pushing it that far left

Leave luminance for now and go back to RGB image.

- Do round of Color / Levels and numerically enter 2.2 in middle slider - things won't change much in the image itself (this is gamma correction needed for color data)

- Copy Luminance image and paste it as new layer on top of RGB image

- Set Layer mode to luminance (last in the list)

- Flatten the image

At this stage - do post processing to your liking (if you want to change color temperature to correct for atmospheric dispersion or want to do some denoising or color saturation or whatever artistic thing you want to do to your image) - or leave as is if you are happy.

 

 

[fifeskies]

5 minutes ago, vlaiv said:

Here is workflow in Gimp that works 99% of time , but you need to have properly prepared data for it.

Data needs to be still linear, but wiped (background and gradients removed) and color calibrated (often referred to as color balanced).

There is only one step of difference between LRGB and OSC data in this workflow - way how Luminance is obtained. With LRGB - you already have it, but with OSC you need to extract it. I'll list OSC workflow and lum extraction step can be skipped for LRGB data (here you replace it with RGB compose to combine R, G and B data into color image).

-

 

Do you have any recommendations for combining Ha and OSC (in GIMP)

I have just obtained a Ha narrowband filter and am planning to add this to OSC images from my Canon 600D (taken at other times , ie when there is no Moon around).

[vlaiv]

1 minute ago, fifeskies said:

 

Do you have any recommendations for combining Ha and OSC (in GIMP)

I have just obtained a Ha narrowband filter and am planning to add this to OSC images from my Canon 600D (taken at other times , ie when there is no Moon around).

Can't help much there - I have not done it myself so don't have workflow in place.

I would probably look into adding Ha to luminance in some way and also adding it to red channel - possibly using some sort of max function (lighten, luma / luminance lighten - try out couple of blend modes in that group).

Stretch Ha separately for blending in with R, but combine with luminance while still linear - possibly outside of gimp with a tool that allows for pixel math?

[fifeskies]

2 minutes ago, vlaiv said:

Can't help much there - I have not done it myself so don't have workflow in place.

Thanks anyway

I will probably start just by making some mono images from the Ha data , these can be quite striking from others I have seen posted on the forum.

[bottletopburly]

For stacking  there is Deepskystacker , for processing there is Startools, simple to learn and get an image you will be happy with just following default settings then you can work on getting the best certainly easier to get your head around ,free trial as long as you like , paid version approx £40 very good value for money 

https://www.startools.org/

 

 

[alacant]

+1 StarTools. A refreshing move away from the levels and layers of the 90s.

For calibration and stacking: Siril.

To make it look nice: DarkTable.

Cheers

 

[Newforestgimp]

11 hours ago, alacant said:

+1 StarTools. A refreshing move away from the levels and layers of the 90s.

For calibration and stacking: Siril.

To make it look nice: DarkTable.

Cheers

 

Startools looks promising actually, had a brief play with it and seems quite straightforward. Im enjoying Siril, as a one product does all its pretty darn good and I think perfect for anyone like my friend who doesnt really want to get involved with the computer side of things at all. The photometric colour balancing basically took a dark post stack image and made it pretty good in one action.

Not heard of DarkTable, will check it out.

Thanks