Thread: F-ratio myth
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Old 22-02-2018, 02:21 PM
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Shiraz (Ray)
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Shiraz is offline
Join Date: Apr 2010
Location: ardrossan south australia
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Originally Posted by Peter Ward View Post
I'm still having problems with this..

With my system in its native F8.0 configuration I can expect around a 10
micron Airy disk. A good match for my 9 micron pixels.

If I reduce the focal length I might get 6 micron airy disks. Those big pixels won't notice any more photons....the aperture has remained the same...hence I'm unsure of what you mean by "more intense"
yep, undersampled images are the odd man out. The star spots will become more intense (ie have more spatially concentrated energy) as the fl decreases, but this change won't be detected. ie, what you see will be determined by the sampling as well as the optics. Which is actually a good example of why sampling was mentioned as being of prime importance way back in the early days of the thread.

Last edited by Shiraz; 22-02-2018 at 05:46 PM.
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