[Guest]

The problem is that the EXIF data is not accurate enough to produce "hard" data. If it was we could just take the delta between the center focus and the corner focus.

 

If things are really extreme we tend to publish a 2nd MTF chart e.g.

http://www.opticallimits.com/samsungnx/6...24?start=1

 

Sample images are a difficult topic. It would have to be a constant scene in order to allow a comparison across different lenses.

What would EXIF data be used for? FL and f-stop?

Personaly, I'd prefer slightly inaccurate data (let's call it "an indication") over just words in the text that are very subjective.

 

I also think that curvature information is sorely missing because the test procedure you are using masks it completely, if I understand correctly. In real life however, there is no practical difference between a lens that has blurry corners due to curved field and one that displays blurry corners for other reasons. So checking charts for corner sharpness of a lens is almost meaningless without knowing how strongly the image field is curved.  Again, I am talking from a practical, not scientific perspective, but still... One lens may have good test results, like the Canon 15-85, but in reality, it's corner sharpness may not be better than that of another lens which tested badly, such as the Canon 17-85.