8 replies to this topic

[Sofee12]

I have a question about the color reproduction of the Seestar S50 and would like to hear opinions.  I've only been using the Seestar for a couple months and have held off on imaging The Veil Nebula.  Last night I tried my hand at the western side.  After about 2 hours of recording, the downloaded denoised stacked image with slightly increased contrast and saturation came out almost totally green.  On processing the image in Siril, GraXpert, AstroSharp, and Gimp today, the nebula was mainly teal and reddish-orange.  I did not highlight any one particular color during processing.  I used a global saturation.  See the image below.  Is the Seestars stacked image algorithm heavily leaning to the green side?  Does it vary from Seestar to Seestar?  I see that the western Veil Nebula is almost entirely teal in color in reality.  I'd like to process the Seestar images to be as true as possible and not make them simply eye-candy.  Any opinions?

 

 

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[pyrasanth]

Very nice. You've captured the witch's broom one of the brighter sections of the nebula. You need a lot more data to smooth out this target- I'd go for it as the result will be worth the extra time spent.

 

Most cameras are largely more sensitive in the green side of the visible spectrum so we have to use techniques like linear fit to balance colour. Things take on a whole new processing workflow when it comes to narrow band/false colour.

Edited by pyrasanth, 25 May 2025 - 05:08 PM.

[Peter Besenbruch]

The Seestar S50 does tend to overemphasize the green. The Vespera II overemphasizes the yellow. The Seestar S30 may be biased a little toward the red. When you process from FITS files, you can include a photometric calibration in your workflow, or you can play with the colors yourself until you like what you see.

[sevenofnine]

This Seestar S50 snapshot looks fairly balanced to my eyes. No post processing 

 

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[Sofee12]

Yeah, I failed to mention I did use photometric color calibration in Siril.

 

I was wondering if it was just the green sensitivity of sensors.

 

Yes, I would like to get about 2 more hours of subs to add to what I already have.  When I see people collecting 20-30 hours, it boggles my mind.  I'm lucky to get that much clear sky in a year!

 

Thanks.

[pyrasanth]

Yeah, I failed to mention I did use photometric color calibration in Siril.

 

I was wondering if it was just the green sensitivity of sensors.

 

Yes, I would like to get about 2 more hours of subs to add to what I already have.  When I see people collecting 20-30 hours, it boggles my mind.  I'm lucky to get that much clear sky in a year!

 

Thanks.

I look on image acquisition as a journey & not a race. It can take a long time to get a set of data that you are truly happy with- I have data sets that have been acquired  over years.

 

- so be a tortoise & not a hare- it's the climb that makes standing on the mountain so much more fulfilling than the destination.

Edited by pyrasanth, 27 May 2025 - 12:34 PM.

[jforkner]

Personally, I think the obsession with color accuracy of DSOs is overrated.  Don’t know of anyone who has actually seen one up-close-and-personal, so who’s to say what is “true as possible”?  Besides, to whom are you going to show the image to that’s going to call you on it if perceived inaccurate?  My opinion is make it look good to you.  Don’t worry about what others think.  Heck, even NASA uses false color techniques to color the black & white images from Hubble.

[sanford12]

Took this last night with a near full moon and Canadian fire haze.

 

Green looks like normal for a S50

Never happened with other nebula.

Edited by sanford12, 09 June 2025 - 03:01 PM.

[AhBok]

Colors for the Witches Broom are interesting. If using a dual-band filter such as the LP filter in the Seestar, the colors are not true. However, this filter still gives a fairly good approximation of the true red for Ha emissions and blue/green for oxygen rich areas. Star color, though, suffers a bit when filtered. For my AP rig, I like to combine dual-band filtered images for the nebula with unfiltered RGB images to get true colors for stars (and approximate correct colors for the nebulae.)

False color images are not my favorite esthetically, though I have made many pseudo-Hubble palette images myself. They can be quite useful in contrasting various features and regions, though.