[soLong]

I think I understand - focus shift ? If so shoudln't the camera/lens have information for compensation ?

... so i'm very slowly gathering the necessary info by old fashioned methods - just needing a programming expert to write the compensation info into the tiny little computer inside my 7D or the chip inside the lens  - is there anybody out there who could do it for the love of it? - or better still (and more honourablly on their part) hello Canon are you there??  - ta very much