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Originally Posted by Nikolas
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Thanks Nikolas, using the scope mentioned in my post! Interesting reading on the CN link you gave me, many thanks.
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Originally Posted by Wavytone
If you can wait for a new model, the one I'd buy for that scope is the ZWO ASI533, slightly larger square sensor and larger pixels, should be a good match.
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Had a look at that, looks interesting and competitively priced! Looking for something a little bit more than 9 mp, I'm using a QHY8L at the moment running at 6Mp, images are good but feeling I could a little better with overall resolution? Do you think I'm asking too much? Does it matter?
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Originally Posted by Startrek
Paul
Sampling in general terms is how well your image train can resolve levels of detail in objects at various atmospheric conditions using a specific pixel matrix on the camera sensor via your focal length / focal ratio
To see if your over sampled or under sampled you need to work out your image scale or pixel scale of your image train ( telescope and camera )
Formula for image scale or pixel scale (P) expressed in arc sec per pixel is -
P= pixel size of your imaging camera ( in microns uM ) x 206.3 divided by your telescopes focal length in mm
Over sampling is < 1.0 arc sec / pixel
Under sampling is > 2.0 arc sec / pixel
In good seeing conditions 0.80 to 1.0 arc sec/ pixel is OK stars will be round and sharp
In average to poor seeing conditions 0.80 to 1.0 arc sec/ pixel will produce slightly fuzzy or bloated stars
It’s most cases and conditions is probably better to be slightly over sampled or around the 0.80 to 1.20 arc sec per pixel mark ( but not critical as atmospheric conditions vary so much )
NB: DSLR’s are generally only useful in telescopes with focal lengths less than 1200mm or > 0.80 arc sec per pixel
Hope the above answers your question about sampling
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Certainly does help Martin...so the ZWO ASI183MC Pro with 2.4um will give me 0.5 resolution and will oversample because of the cell size but the ZWO ASI533 with 3.76um will give me 0.78 which would be better? So the bigger the um will give me a better match? Forgive me if I have it a bit mixed up!
I have to agree with Greg, great summary!
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Originally Posted by gregbradley
Nice summary Martin.
Greg.
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Originally Posted by doppler
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Rick, thanks for this, really helped!