Hey Tech,
I have a question that I'm sure has been addressed on this forum somewhere at least a million times. Can you give me the short version of any known advantage of a 9 micron photosite (as in A22) vs. a 7.2 micron photosite (as in A75) on a Dalsa sensor? I'm considering 'upgrading' to an AFi5 and perhaps not an AFi7. Is there any kind of trade-off with a larger photosite (Afi5) or am I just loosing the resolution (AFi7) with no other benefit? Thanks!
David
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Pluses and minuses.
In theory, smaller photosites produce more noise than larger photosites. But more resolution produces finer detail and minimizes single shot artifacts, like moire, etc. Smaller photosites require higher resolving lenses for the same level of sharpness.
Much of this is theoretical, however. The photosite is only one part of the equation, as Tech Talk alluded to. The software algorithm can (and does) compensate for the deficiencies of the actual sensor. And there can be other technical advances in the sensor itself as to how charges are handled that can alleviate issues that would normally be incurred form a smaller photosite.
And even lens resolving power can be a plus/minus issue. Say you have a 7.2 micron photosite vs a 9 micron photosite. A particular lens would render a sharper image on the 9 micron photosite. Especially as you stop down. However, smaller photosites are typically packaged into sensors that provide more of these photosites, which then yield more resolution, which then yields more detail and information, which may also compensate for the slight apparent and perceptual lack of sharpness compared to the larger photosites.
There is more to an image than sharpness (or perceived sharpness). Your particular application may dictate which sensor makes the most sense. And it is recommended that you push the envelope in testing both.
Steve Hendrix
www.ppratlanta.com/digital.php
