Tamron lens with small nick - Effect on focus?

[Thomas68]

 I have a Tamron 18-200mm f/3.5-6.3 DI-II VC AF lens that I'm using with my Canon T6s. The lens has a small nick off center. Would this have any effect on the focusing? It doesn't show up in any of the photos I've taken, but it sometimes struggles to focus.

[jrhoffman75]

Since autofocusing relies on contrast detection I would not expect the nick to the cause of any issues you have with the lens focusing. 

[Thomas68]

Thanks that helps. I've always shot with Nikons. This is my 1st Canon dslr.

[normadel]

Thank you for accepting my answer! 

I do have to add that it would be the same for a Nikon. Optics and focusing aren't different for Canon and Nikon. You don't relearn photography when switching!

[normadel · Accepted solution]

A nick on the front element of a lens will not show on viewfinders or in photos. It will have no effect on focus for the same reason. If the sensor doesn't see it (because it it way way to close to be focusable), it is, in effect,  invisible.

If lens is struggling to focus, that could be for a lot of reasons....insufficient light, insufficient contrast at the focus point, you're not keeping the focus point over what you want to focus on, you're too close to the subject, are the obvious ones.

[ebiggs1]

"Would this have any effect on the focusing?"

A better answer is 99.99% no, it will not effect focus but in reality there is always that chance.