[Xastoul]

Is there different test method to measure the vignetting for a lens? Because I've check on other site lens review and they seem to end up with almost twice the vignetting value compared to here.



This time I did some research just to be sure I'm not asking for something stupid... I hope I did not forget something.



There are a lot of example but I'll cote only this one,



Nikkor AF-S 50mm f/1.4 Ghere it get a vignetting value of .56 Ev



On the other site the have a value of 1.00 Ev



They are both shot with a Nikon D200



Most lens have a noticable difference, some like the Micro 40 mm , have almost the same value.









Is there a reason for that?

[Klaus]

We test the vignetting at infinity focus and using standard JPEGs (sometimes RAWs for cross-comparison) based on an evenly lit, back-illuminated test target. The displayed peak in the histogram (representing the gray value) is at the 3/4 position (we overexpose by 1-1.3 stops during the procedure). This approach is the same across all tested systems, of course.



So differences between the sites can occur due to

a. a different focus distance

b. a different exposure characteristic

c. a different S curve in the JPEG/RAW

d. a different tool used for the analysis of the test data