How do you process a Full Spectrum modded image?

[PaulInNorthMichigan]

For my 1st project of the year I gave my new Nikon D5300 modded camera a workout on Orion.

I know that there are flaws in my whole process but the most perplexing would be how to deal with the overwhelming red in the Orion image; retaining nebulosity while getting a dark sky where it should be dark.

I just took this through a quick top to bottom processing with the latest version of StarTools that I downloaded earlier today. I used the legacy color for my Nikon D5300 camera. My original FITS image was stacked in Astro Pixel Processor; using minimal tools for the integration.

It would be excellent if it would be possible to retain some of the beautiful glow of Orion without having an entirely red background.

210314_Orion_1st.jpg (362.25 KiB) Viewed 5813 times

[astrosatch]

For start I would put UV/IR CUT filter in chain. If you can afford L-enhance or similar filter would be even better. The problem with full spectrum sensor is not overwhelming red color(this can be processed), but bloated stars that really distracts from object and is difficult to correct.

Andrej

[hixx]

Hi Paul,
there are a number of parameters to play with:

In 'AutoDev' Module: Balancing faint details vs. noise
1) Set the ROI to include all details - do not pay attention to noise at this step (If you want less faint details just include less faint areas in the ROI)
2) Increase 'Ignore Fine Details' Parameter. Noise will be pushed down. Increase further until no further improvement.
3) Reduce 'Shadow Linearity' until faint details start to get impacted. This will darken the background. It is OK if some noise remains at this point. Usually 'Denoise' modules should be able to handle.
Further measures may help controlling noise (and faint details):
- In 'Contrast' module 'Shadow Dynamic Range' may be reduced strongly. Set 'Shadow Detail Size' to 10-15 Pixel.
- In 'SuperStructure' module, 'Isolate' or 'DimSmall' presets will push down noise further.
- In 'Flux' module the 'Noise' preset might help as a last resort.
- In Color Module, reduce 'Dark Saturation'

Also make sure not to use Masks extensively in Wipe Module

clear skies,
jochen

[PaulInNorthMichigan]

For start I would put UV/IR CUT filter in chain. If you can afford L-enhance or similar filter would be even better. The problem with full spectrum sensor is not overwhelming red color(this can be processed), but bloated stars that really distracts from object and is difficult to correct.

Andrej

Andrej: Thank you for this piece of advice. I do actually have the Optolong L-Pro on back order so it appears that I may be on the right track to clean up my future images better.

[PaulInNorthMichigan]

Hi Paul,
there are a number of parameters to play with:

In 'AutoDev' Module: Balancing faint details vs. noise
1) Set the ROI to include all details - do not pay attention to noise at this step (If you want less faint details just include less faint areas in the ROI)
2) Increase 'Ignore Fine Details' Parameter. Noise will be pushed down. Increase further until no further improvement.
3) Reduce 'Shadow Linearity' until faint details start to get impacted. This will darken the background. It is OK if some noise remains at this point. Usually 'Denoise' modules should be able to handle.
Further measures may help controlling noise (and faint details):
- In 'Contrast' module 'Shadow Dynamic Range' may be reduced strongly. Set 'Shadow Detail Size' to 10-15 Pixel.
- In 'SuperStructure' module, 'Isolate' or 'DimSmall' presets will push down noise further.
- In 'Flux' module the 'Noise' preset might help as a last resort.
- In Color Module, reduce 'Dark Saturation'

Also make sure not to use Masks extensively in Wipe Module

clear skies,
jochen

Thank you jochen: I will try these steps and feedback how this impacts the image I've taken. I know that StarTools are very powerful. Since Orion is going away soon it would be nice to be able to restore the captured image that I have.

Another thing which I have been considering is combining a set of unmodified camera data to mix with the full spectrum data within Astro Pixel Processor.

[PaulInNorthMichigan]

Looks like my reply back didn't take.

Jochen, thank you for your help. With your suggestions I completely removed the over powering red. Although there are several flaws in my image it is vastly improved.

210314_OrionTry2.jpg (464.81 KiB) Viewed 5715 times

Defect wise my eyes see fat stars and some distortion surrounding the nebulas. I will at least try removing the fat stars; at that point will be quite happy with the results.

Thanks a lot for your help!

[Burly]

It mat be worth reading this article https://www.cloudynights.com/topic/7461 ... ry10867894 regarding the D5300 and as an experiment reprocess as in instructions just to see if it makes a difference to you , make a copy of your files ,basically run all your files lights darks bias flats etc convert to adobe dng then run through marks program to eliminate concentric rings then stack and process as normal.

[PaulInNorthMichigan]

It mat be worth reading this article https://www.cloudynights.com/topic/7461 ... ry10867894 regarding the D5300 and as an experiment reprocess as in instructions just to see if it makes a difference to you , make a copy of your files ,basically run all your files lights darks bias flats etc convert to adobe dng then run through marks program to eliminate concentric rings then stack and process as normal.

Thank you for the idea. I will look at this.

Would this option be better than trying to mask out the bloated stars in StarTools?

[Burly]

No but may help ,matter of trying it out.

[hixx]

Looks like my reply back didn't take.

Jochen, thank you for your help. With your suggestions I completely removed the over powering red. Although there are several flaws in my image it is vastly improved.

210314_OrionTry2.jpg

Defect wise my eyes see fat stars and some distortion surrounding the nebulas. I will at least try removing the fat stars; at that point will be quite happy with the results.

Thanks a lot for your help!

Hi Paul ,
looking at your improved image it seems quite OK except the color - there should be strong O III - green in M42. Also the Ha regions might use some stronger red. You may want to try some steps in Color module:
- Scientific rendering - it will bring back color to otherwise whitish highlight areas (center on M42). Also stars should come in true color not white
- Matrix: even though your cam is modded, your camera profile might bring back some "lost" hues. You may then want to reduce Saturation to 100-150% - the profile will bring a lot color.
- Be careful with the Cap Green slider in order not to whiten all OIII
- Highlight Repair may re-vitalize your stars

You also seem to have reduced blue and saturation quite strongly to get rid of purple or blue fringing of the stars - there is a better way to do this in the Filter Module:
- Put the stars with fringes in a mask - making the stars green. Be sure to include the fringe.
- Set the 'Filter' Mode to 'Fringe Killer'.
- Set the 'Filter' Width to 1 - the lower value makes the filter more responsive to colors close to (but not exactly the same as) the selected color.
- Click on the colored star halos in different places to eliminate the fringes completely.
- 'Keep the result when you are done.
This path leaves you more freedom adjusting the "real" signal
A lot of it comes to taste - feel encouraged to process the same image over and over again in different directions and characters - there are a number of ways to produce impressing results. Be sure to check out the new manual. In the new Tutorial section all step-by-step guides from Guy's User Notes are included - from basic operation up to special techniques.
clear skies,
jochen