M31

Hi Michel,

First of all, it looks really good for only 73 mintues of integration time I think 😉

Your stretch is also very nice, you can still see lots of faint stuff in the background! I think you would be amazed of the result, if you could get 10 hours of integration time...

Some suggestions:

• I notice a red glow on the lower right side of M31, maybe that can still be corrected gently with the "remove light pollution" tool.
• Maybe you can try to get the core of M31 a little bit more yellow. If you would load the data into the RGB combine tool, you could gently tweak the RGB multipliers. Another tool would be to try the selective color tool in APP or PS.
• Regarding the stars and their shapes, have you tried integrating with star shape weights? Maybe that can improve the stars a bit more. It will give more weights to the frames with the sharpest and roundest stars.

Cheers,

Mabula

Thanks for the tips! i'll run it again when i have more data and with the star shape weights. I just took a look at the combine RGB tool. I'll try that later, but it looks pretty advanced for my level 😉 

I do have another question, when i just opened APP and loaded my saved FITS file, all the stretch/contrast/HL  etc. data was reset to default (so nothing is saved except the picture itself) and when i loaded the picture again it was really bright. Is there a way when you save the picture that all sliders remain as where i left them? So if i shutdown APP i can continue to tweak the sliders again later from the position you left them?

Thanks again for your feedback, at least i have new things to learn in APP.

Cheers,

Michel

Hi Michel,

Yes, the RGB combine tool is more advanced and might be a bit overkill for your purpose. The star color calibration tool needs some more work I think 😉 so I will put that on my RFC list.

Regarding the slider settings, no not yet, I guess I would need to store metadata in the original FITS stack for the slider values which you can then recall using some button in the preview filter? Is that what you refer to?

Cheers,

Mabula

Hi Mabula, yes that's what i mean. Because app doesn't give a warning when shutting down (or when you want to shut it down for whatever reason) and re-open it, you can't continue where you left off regarding the sliders (they are all at the default position again)

Thanks! I am really happy with the program! It is fairly easy and very good results for beginners!

Hi Michel,

Thanks.

I will need to give this some thought on the best way to implement this, possibly it's best to use some form of cache for images and their sliders settings? That would be the easiest to implement I think.

Mabula

Hi Michel,

Thank you for sending me the integration fits file. I have applied the "remove light pollution" tool and color calibration using the RGB combine tool, results are sent to you with dropbox.

Some screenshots of the light pollution removal and the color calibration with settings in the RGB combine tool and the end result:

Let me know what you think of this.

Kind regards,

Mabula

Color in this M31 looks really good to me (and overall a really nice image, too)!

Scott -  http://www.astronomersdoitinthedark.com/

Yes, thank you Scott, I think it's superb for only 73 minutes of integration time 😉

Cheers,

Mabula

Hi Michel,

I am about to release APP 1.056, and it has a much improved star color calibration module, I have used your initial stack which was very blue for testing, so this is what comes out of it on your M31:

This was the data that needed calibration:

more details in the release notes of 1.056 😉

Mabula

APP 1.057 again will have a further improved Star Color Calibration module.. the old module killed saturation sometimes when using the Black Body modes. The new module will be more robust and preserves more color saturation.

Michel's M31 is a very nice test image for this, since the original data is almost completely blue.