01-15-2011, 07:53 PM
[quote name='Klaus' timestamp='1295013502' post='5499']
Sorry but that's merely an opinion but not a fact. If a wide or ultra-wide lens has a poor corner performance this is of course relevant. Possibly not for you but it is THE primary criteria for me here. Unlike a tele lens the wide- or ultra-wides have to provide a uniform performance across the frame IMHO. In fact I don't even care for the center performance here - it is always "good enough" here anyway.
[/quote]
Of course, the entire frame is important... my comment was about how PZ chooses "border" and "extreme border" on the image circle radius where they are only representative of a minute spatial area on the entire frame.
Again... this is about:
1. Selecting only 3 points.
2. Two of those points being less important, spatially, on the image frame
I've seen many lens MTF curves dip in the middle, at around the 12mm mark, where the significance of the MTF to the image frame is at its highest. These lenses may have good dead-"center" and "extreme border" values but the final image resolution will be less than of a lens that has low "center" and "extreme border" values but a high MTF at around the 12mm mark.
GTW
Sorry but that's merely an opinion but not a fact. If a wide or ultra-wide lens has a poor corner performance this is of course relevant. Possibly not for you but it is THE primary criteria for me here. Unlike a tele lens the wide- or ultra-wides have to provide a uniform performance across the frame IMHO. In fact I don't even care for the center performance here - it is always "good enough" here anyway.
[/quote]
Of course, the entire frame is important... my comment was about how PZ chooses "border" and "extreme border" on the image circle radius where they are only representative of a minute spatial area on the entire frame.
Again... this is about:
1. Selecting only 3 points.
2. Two of those points being less important, spatially, on the image frame
I've seen many lens MTF curves dip in the middle, at around the 12mm mark, where the significance of the MTF to the image frame is at its highest. These lenses may have good dead-"center" and "extreme border" values but the final image resolution will be less than of a lens that has low "center" and "extreme border" values but a high MTF at around the 12mm mark.
GTW