Optimal sampling
Dear fellow astrophotographers.
Perhaps this topic has been discussed over and over, but I thought it would not hurt to have a look at optimal sampling yet again.
If we would like to get the most out of a telescopic imaging system in terms of resolution and real estate, perhaps slight under-sampling combined with dithering and drizzle integration might yield most optimal results.
Slight under-sampling usually means we can use a smaller telescope that is less demanding on the mount and is cheaper than a larger telescope of the same built quality. It also means we cover a somehow larger field in our images as opposed to imaging at less arc-seconds per pixel with the same camera. Drizzle integration when applied properly recovers some detail thus increases resolution in the final image.
This was my exact thinking when I recently bought a new telescope. For good or bad, I resisted a very strong temptation to get a larger telescope. My new imaging system will sample outer space at 1.21 arc-seconds per pixel. Drizzle x2 will increase the scale to about 0.6 arcseconds per pixel, but more realistically I feel that the true detail in final images will be probably comparable to what I would get when imaging at about 1 arc-second per pixel (maybe less), while the filed of view captured in final images will be larger.
So in theory, if I permanently incorporate drizzle integration in my data processing, I should be getting seeing-limited detail as long as I will be shooting from a near coastal location in Australia. Of course I have not considered light pollution, pixel well depth etc, but that I feel is a different story.
Any thoughts, and also pointing errors in my reasoning, will be highly appreciated.
Suavi
|