Dithering confusion

I have what may be to some a question with an obvious answer, but I cannot seem to get enough info to wrap my head around the solution.

In the PHD2 Advanced Setup—>Global dither settings I have “random” checked, with the default Scale setting of 1.0.

In Voyager’s “On the Fly” Guide/Dithering tab, I have the Dithering Max Deviation checked, but have no idea what setting to use for a dither of 10 pixels.

My guiding image scale is 0.84"/px, with an imaging scale of 1.1"/px.

What should I be using for PHD2 scale setting, Voyager pixel setting, or both to get a dither of 10 pixels?

Thanks for your time in answering.


Hello Eric,

i hope this thread can help you:

Voyager doesn’t use PHD2 setting for dithering but decide in autonomy so leave 1.0 on default scale. Pixels in Voyager are related to guide camera if you are guiding, if not are related to main camera. In the second case you have nothing to calculate in the first you must do this calculus:

Scale imaging/guiding = 1.1 / 0.84 = 1.309523…
10 pixel in guide camera = 10 / 1.309523 = 7.63 pixel in Main camera

If you want to move main camera of 10 pixel :
10*1.309 = 13.09 pixel to put in dithering in Voyager

All the best

PS i never used scale field in PHD2 and i dont know if work from external program (probably yes) , if work you can just input scale calculated of 1.309 and leave 10 pixel in Voyager. Like i said never tried.


Thank you, Leo. This makes perfect sense compared to what I’ve read in PHD2 and other forums.

Have a great day, and a Happy New Year!


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