Recently I had the opportunity to borrow a Tamron 17-50mm f/2.8 XR Di-II LD Aspherical [IF] and was not impressed by the lack of sharpness when shooting wide open. I could not figure out for the life of me why all of my photos seemed out of focus and then for some reason thought that it might be a front or back focusing issue. So I put the D7100 on a tripod and put a book on the couch with a ruler at a 45˚ angle. At f/2.8 I noticed a front focusing issue. According to my math, the camera is focusing 10mm in front of where it shows the focus point was.
I did attempt to adjust the settings on my D7100 to compensate for the problem, but it made no difference.
At f/4 it focused correctly, so I'm wondering if it is possible that the lens had a misaligned element. But if that was the case, wouldn't it affect focal points regardless of aperture? The only argument based on what I just said is that as the aperture closes, the focal range increases.
Regardless, I found the lens more of a headache than anything else. I am in the market for something similar, but a I am on a tight budget. I have about $400-$500 to play with and am wondering what lens is recommended for sharpness (and correct focus) when wide open.
I am also considering maybe getting a Sigma 105mm (or something equivalent to it). The main thing I am looking for in a lens is image stabilization. I am on medication that gives me the shakes.
I did attempt to adjust the settings on my D7100 to compensate for the problem, but it made no difference.
At f/4 it focused correctly, so I'm wondering if it is possible that the lens had a misaligned element. But if that was the case, wouldn't it affect focal points regardless of aperture? The only argument based on what I just said is that as the aperture closes, the focal range increases.
Regardless, I found the lens more of a headache than anything else. I am in the market for something similar, but a I am on a tight budget. I have about $400-$500 to play with and am wondering what lens is recommended for sharpness (and correct focus) when wide open.
I am also considering maybe getting a Sigma 105mm (or something equivalent to it). The main thing I am looking for in a lens is image stabilization. I am on medication that gives me the shakes.