Tamron SP AF 17-50mm F/2.8 XR Dill VC

[mike_dunn2]

<p>I bought the above lense for my Nikons N65, N90, and D-90.<br>

The problem is the auto focus will not work with the N90. It works OK with the N65. I tried other lenses with the N90 and they work OK. Is the Tamron lense not compatible with the N90 or is it defective? Haven't had a chance to go back to the camera store.</p>

[Peter_in_PA]

<p>The lens will not work well on your film cameras at all, don't you get sever vignetting on it? The N90 SHOULD be able to focus any AF or AF-S lens, but third party lenses sometimes have limitations.</p>

<p>That's a fantastic lens for the D90, not so much for your film cameras.</p>

[mark_drutz]

<p>That is an excellent lens, but it is designed to be used with DSLR's that use APS-C sensors. These sensors are smaller than a 35mm negative so the lens will not cover a 35mm negative. Sigma and Tamron make lenses in the 24-70 f/2.8 and 28-70 f/2.8 range that will cover about the same field-of-view on a 35mm SLR that the 17-50 covers on your DSLR.</p>

<p>Lenses intended for Nikon 35mm SLR's will work with a 1.5 crop factor on a Nikon DSLR with an APS-C sensor. But a lens intended for an APS-C sensor DSLR will not work well with a 35mm SLR. Different lens makers have different designations to tell which format the lens is designed for. Nikon uses DX for APS-C lenses and FX for 35mm SLR's and full frame DSLR lenses (which can also be used on APS-C bodies with the crop factor).</p>

<p>The 1.5 crop factor means that you multiply the focal length by 1.5 to get the 35mm equivalent focal length.</p>

<p>Confused?</p>

<p> </p>

[eric_arnold]

<p>the DiII designation means digital-only. it is a DX lens. if you want a lens which will work on both film and digital get the 28-75 Di instead.</p>