alundeb Offline • • • • • Upload & Sell: On

theSuede wrote:
One should do a reality check every once in a while.
Ask the question  Exactly what are we trying to do?
A 40mm f/2.8 lens has a nominal front pupil diameter of (40mm/2.8) = 14.3mm
The area of that pupil is pi*(14.3/2)^2 = 160mm˛
The pixel area of a NEX7 is about 0.004^2 = 0.000016 mm˛
To get perfection, we have to condense light hitting a 160mm˛ input area into a 0.000016mm˛ focal point.
Want to get that condensation rate in numbers? It's:
160 / 0.00016 = 10,000,000 : 1 (tenmilliontoone)
Relax the sharpness to a 3x3pixel area, and you still have a 1,000,000 to 1 condensation ratio.
Considering that we now combine two optical systems that weren't even custom made to complement each other, this result is amazing. ...Show more →
Yes, it is amaizing both to think about the numbers (respect to you optical gurus), and to see that the SB actually is a useful tool.
The two obvoius costs of added distortion and lateral CA are of the kinds that can be corrected in SW with minimal negative impact.
The extreme corners look a little worse than the corners I showed (which correspond to about Imatest "corner" image height). One can say they did cut some corners to get the adapter small
About the SA / contrast reduction, I will try to look a bit more into that.
