Tamron 17-50 f2.8. problem with sharpness

[Robert Kaleta]

I've purchased this lens a week ago and i've taken quite a few photos with it now. However most of them seem out of focus. At first i thought it was because of the f2.8 which i was using but that would make the photo soft not out of focus.

Here are some examples. Shot at f2.8 1/80. handheld 50 mm. Focus was on her left eye. Almost every picture has a problem like that. Should i take it back to the shop?

http://farm4.static.flickr.com/3236/2499653553_c23952242b_b.jpg

http://farm3.static.flickr.com/2062/2499663097_e7bb17f00d_b.jpg

http://farm3.static.flickr.com/2367/2499671829_4e34222a95_b.jpg

 

[ChickenFriedRyce]

An element could be off center in your lens, I would take it back and take pictures with it there and show them the results.


EDIT: Also try Manually focusing, if nothing is sharp, take it back immediately.

 

[JerryPH]

IMHO, it's inexperience, not the lens.

One eye would be sharp, the other off. Just becuase a lens can do F/2.8 doesn't mean it's good to always use nothing but F/2.8.

Try upping it to F/4 or F/5.6 and retake the same shots. We all know that the extremes of the aperture ranges are not usually where a lens is sharpest. A big aperture is also very sensitive to having an accurate focus. A shallow DOF is the main effect of a larger aperture opening.

 

[ChickenFriedRyce]

Well of course, but I wouldn't think they'd look that soft, if soft at all.

 

[Robert Kaleta]

ChickenFriedRyce:
Thanks for the advice. I'll probably go to the shop on monday and have a little chat.

JerryPH:
To be honest with you inexperience was my first thought. I've never used aperture that wide. On the other hand i expected at least some part of the photograph to be sharp. What i noticed is that this lens might have a front focus problem as in some or even most of the shots the sharp part is "closer" to the lens than i intended it to be.
I'm going to print this (http://photo.net/learn/focustest/) sheet and see if i'm right.

Thanks for your help guys.

 

[Early]

Retest the lens using a tripod. 1/80th of a sec. isn't a whole lot of speed for many photographers.

 

[Mav]

It seems like a lot of people have focusing issues with the third party lenses, Sigma in particular, but Tamron too. I haven't heard much about this specific lens, but there's always the possibility that the lens is front-focusing or rear-focusing. There's a focus test chart that you can download and print from here to test out your lens.

That said, I do usually shoot my f/2.8 mid-zoom at about f/4 just for a little more depth of field to avoid the issues like you're having. And like Early mentioned, 1/80s is a tad slow particularly if the subject was moving. I don't go below 1/125s if I can avoid it, and usually use a flash. I thought I might have been having focus issues when I got my lens, but I printed out that chart and tested it and it was fine. Just needed to work on technique. I have the Nikon 17-55 though, not known for focusing issues. Can't say the same for Sigma and Tamron, so definitely test yours.

 

[Robert Kaleta]

I've done the front focus test and it's spot on. I guess there's nothing wrong with the lens it's what JerryPH said " IMHO, it's inexperience, not the lens."

And you were also right about the shutter speed.

Thanks for your help guys.