Front focussing?

[ab2012]

Was reading a review and there was disappointment that the lens was front-focussing? "I was very disappointed to yet receive another front-focusing copy"
Is anyone able to enlighten me?
Thanks.

 

[Russ77]

Back/front focusing is an issue where the lens/camera combo isn't calibrated properly and the lens either focuses behind the intended focal point or in front of the selected focal point.

The mid/top end cameras tend to have micro adjustment which allows you to correct this.

However sometimes the lens is just a "bad copy" and needs to be sent back to the maker for adjustments/replacement.

 

[ab2012]

Thanks.But how would you know if there was an issue? Wouldn't focus prpperly?Image quality?

 

[Russ77]

Thanks.But how would you know if there was an issue? Wouldn't focus prpperly?Image quality?

If it's badly front/back focusing then you would see it in the pictures you've taken. The bits you want in sharp focus would appear to be soft.

There are test you can do for this problem but unless you think you've got problems it's probably not worth testing

 

[ab2012]

Cheers for that!