08-26-2014, 10:55 PM
Imatest has nothing to do with the correctness of the CA figures. CAs vary rather heavily between lens samples - I suspect due to variations in centering. The CA readings are taken in all 4 border regions and then "plain" averaged. I reckon we could improve this somewhat by just taking the 2 middle figures while ignoring the extremes.
But yes, CAs are the most unreliable figure we provide.
But yes, CAs are the most unreliable figure we provide.