15th Feb 2024: Astro Pixel Processor 2.0.0-beta29 released - macOS native File Chooser, macOS CMD-Q fixed, read-only Fits on network fixed and other bug fixes
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When I finish my images, I found that my background looks terrible, how can I fix this to make my background smoother or better?
And how to create a "Luminance" file with my RGB images?
Thank you!
@alexlee24 Hi,
It is hard to say what caused this without more info. What camera did you use? What calibration files? Exposure time, gain/offset/iso, temperature? Please try to give us as much information as possible.
Thanks, Wouter
@wvreeven I use Canon90d with VixenED102ss, the images were 120sec*100 iso1600 with dither, and I have dark bias flat and dark flat, the environment temperature is about 25C and have 95% humidity with Bortle scale 5~6.
Thank you.
@alexlee24 Thank you for the additional info. How much do you dither? For APP to work well, you need to dither at least 15 or even 20 pixels in the imaging train. Since all imaging software let you set the dither offset in the guide train, you need to compute the corresponding offset in the imaging train using the plate scales of both trains to make sure that you have a sufficiently high dither offset.
The image that you posted, is that the integration result? In what way don't you like the background? Too dark? Too noisy? Something else?
@wvreeven Ahh...I only set 5pixel (RA only) per image for dither.
Yes, this image is after integration and tools. I think my background looks not "average" like some pixel is brighter than other pixels, it makes my background looks like a lot of grey squares. It's obvious at my bottom left. Maybe too much noise? or decrease too much noise in HSL to make this too evident?
Thank you.
@alexlee24 Can you post the image as is after integration without applying any tools? Just load the image in the image viewer in APP and then take a screenshot.
Thanks.
@alexlee24 I think the background looks like it is expected when using an uncooled camera. More dithering will help but there always will be chromatic noise in the background. Using a cooled camera combined with proper dithering will suppress that a lot more.
@wvreeven Thank you. How many pixels per image for dither do you suggest for DSLR? No budget for a cooled camera right now 😥 .
Thank you. Cheers.
@alexlee24 I don't think there is a difference in dither settings for cooled and uncooled cameras. I'd say go for 20 pixels and see if that helps. Don't expect miracles though. Noise from uncooled cameras is notoriously hard to beat.
