[quote name='Klaus' timestamp='1293433853' post='5219']
We obtain the vignetting data straight from camera JPEGs (unlike the MTFs). Your argument is technically correct but the data reflects the real world user experience on the system where images simply underly a certain tone curve (just like film). A real world approach is hardly a fundamental error though. :-)
Frankly its also irrelevant - the results remain cross-comparable within a testing system.[/quote]
Even if we followed a linear approach - the results wouldn't be pure anyway. The micro-lenses as well as the characteristic of the photo-diodes of the sensor "pollute" the results, of course. Ultra-wides don't vignette quite as bad as the data suggests but who cares how a lens behaves without a camera ...
We obtain the vignetting data straight from camera JPEGs (unlike the MTFs). Your argument is technically correct but the data reflects the real world user experience on the system where images simply underly a certain tone curve (just like film). A real world approach is hardly a fundamental error though. :-)
Frankly its also irrelevant - the results remain cross-comparable within a testing system.[/quote]
Even if we followed a linear approach - the results wouldn't be pure anyway. The micro-lenses as well as the characteristic of the photo-diodes of the sensor "pollute" the results, of course. Ultra-wides don't vignette quite as bad as the data suggests but who cares how a lens behaves without a camera ...