Dithering OSC camera affects Resolution - Forums

Topic starter

Feb 3, 2019

A question really.

Does dithering a OSC camera improve resolution? Its used to reduce noise for sure. I had Drizzle with my old Meade DSI cameras and that movement in acquisition or in post-processing improved resolution. Am I right that dithering that overcomes the bayer matrix interpolation routines should likewise improve resolution?

GlennB

Wei-Hao Wang

Feb 3, 2019

Yes, dithering helps to improve resolution, if you employ processing algorithms like the Bayer Drizzle to avoid interpolation is the Bayer array.

glennb44

Topic starter

Feb 4, 2019

Thanks Wei_Hao.
Have you used this much? Can you show an example maybe?
Would dithering settings in PHD2 towards the larger end of the scale be a good starting point?

GlennB

Wei-Hao Wang

Feb 4, 2019

You can check my latest M31 image in my gallery. It’s made with Bayer Drizzle. You will have to look at the largest version of that image to really see its effect on improving resolution.

That being said, for this to really work, many things have to be done right or to go right. Dithering is just a tiny small element in it.

You can try various dither scale, and examine the resultant images. Check the offset between the images by zooming in like crazy. You should use the scale that can give you a few pixels to about 10-20 pixels of offsets between subsequent images. Too large or too small isn’t good.

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Jonathan W MacCollum

Feb 4, 2019

Yes bayer drizzle is totally worth it for osc. My widefield show huge improvement on how the stars look with it even at 1.0 scale. The natural periodic error of my cgem suffices as enough dither for it to work well when unguided.

glennb44

Topic starter

Feb 6, 2019

Thanks Jon
Wei-Hao, man what a great M31. No pixelation on my screen at max zoom, many background galaxies, pin sized artifact free stars. I'll use you advice for sure.
Who needs mono!
I'm still looking for the Bayer Drizzle software….

ClennB

Wei-Hao Wang

Feb 6, 2019

Hi Glenn,

You can try PixInsight or Astro Pixel Processor. Both can do Bayer Drizzle. DeepSkyStacker can do too, but it’s less sophisticated than the other two.

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