Dudd Lenses

[God]

Hi,

I was wondering how you actually tell you have a dudd lens - I see a lot of talk of people saying they have had a bad lens at some point and taken it back to swap and the replacement has been sharper, but how do you actually know its not right (aside from comparing one to another, which most people cant do).

Thanks!

 

[God]

Nothing at all people...?

 

[Davec223]

It is normally really obvious, the picture is soft, out of focus or similar issue, you can then do controlled tests to determine the problem, normally back/front focus causes most issues.

HTH.