Bad lens copy

[quackal]

In reading reviews and forums, I've read that it's possible to get a bad copy of a lens.
How can you differentiate between a bad copy and just bad shooting techniques (camera shake, focus, etc.).....what defining characteristics would you look for before actually sending back a lens for workmanship?

thanks!

 

[KmH]

Yep, the challege is to know which is which, though if a photographer has little experience and/or knowledge of photography, it's more likely the photographer that's the problem, rather than the lens.

Over the years there have been many times people have asked me to check their lens and 99% of the time there is no problem with the lens.

Most of the reviews that I have seen that mention lenses that have a noticable degree of quality variance, are for 3rd party lenses.

 

[table1349]

I agree with KmH, most of the time the issue is with the shooter. The only two tests I think are valid for a lot of shooters are:

1. Does the glass mechanically operate correctly, focus ring moves smoothly, zoom if appropriate moves smoothly and quietly, no noticeable rattles etc.

2. Nikon D70 Focus Chart The focus chart test works for any make of camera. If it is determined that there is an actual focus issue, this can usually be resolved by sending the lens back to the manufacturer to be re calibrated. In fact, I prefer this to exchanging for another lens. Yes it cost me a few bucks for shipping and I am without the lens for a few days, but the lenses I have sent in for calibration come back tack sharp.

 

[quackal]

Got it; thanks very much for the response!

 

[Dallmeyer]

Does it rattle when you jiggle it next to your ear . If you make a picture and one edge is sharp but the opposite edge is blurred - element/group is out of alignment. Does the front of the lens falloff when you unscrew a filter..You can tell i'm used to using only the best!