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Old 18-09-2017, 01:55 PM
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Slawomir (Suavi)
Amateur Photon Collector

Slawomir is online now
Join Date: Sep 2014
Location: Proserpine
Posts: 3,002
This is such an interesting thread

I have been thinking..(oh no!)... and came to a conclusion, that perhaps it wouldn't be entirely incorrect to assume that small pixels are more demanding on optics than large pixels, except for the size of corrected circle?

I feel it is not so easy to achieve the same level of off-axis optical correction on a smaller telescope with small pixels, as it would be with a longer focal length combined with large pixels, given both are giving exactly the same image scale. A small telescope will have more significant field curvature that needs to be corrected/flattened, and then of course diffraction becomes more significant with smaller apertures.

And since most amateurs are on a fairly tight budget, rare are setups that can take a full advantage of small pixels with quality small optics, good mount and excellent dark skies. I feel we more often see images taken with sensors with small pixels that are put at the end of a less than perfect (“mass” produced) optics, less than perfect mount and in less than perfect conditions - city backyards/balconies. It would be a rather rare sight to see an FLI 16803 attached to a budget but large telescope riding on EQ6/8 and set up on a balcony in a city.

So perhaps in many cases effects of diffraction on a small telescope and limitations of small pixels are actually not the main “issues” affecting quality of data?
What say you?
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