12-01-2010, 11:55 PM
Hi Klaus... I had a bit of time on my hands (surprise!) and following your lens test FAQ, I calculated the image circle radius points for the TS-E 17L in both centered and full 12mm vertically shifted positions.
When I graphed the photozone recorded MTF results corresponding to these points, I found an usual dip in the resulting MTF curve coming from the "Centered: Border" measurements. But the "Centered: Extreme Border" values seemed to be within tolerance. Just letting you know what I noticed after trying to visualise what the whole image circle looked like:
![[Image: 5225079136_a8a81a0ec6_o.png]](http://farm5.static.flickr.com/4104/5225079136_a8a81a0ec6_o.png)
As a side note, shifting horizontally would've been better because shifting vertically misses out 14% of the total image circle area.
GTW
When I graphed the photozone recorded MTF results corresponding to these points, I found an usual dip in the resulting MTF curve coming from the "Centered: Border" measurements. But the "Centered: Extreme Border" values seemed to be within tolerance. Just letting you know what I noticed after trying to visualise what the whole image circle looked like:
As a side note, shifting horizontally would've been better because shifting vertically misses out 14% of the total image circle area.
GTW