Many people detest the thought of purchasing an EF-S lens. However it must not be forgotten that such lenses are optimised for the APS-C or crop sensor cameras because they are designed for them. Personally I was not going to purchase such a lens but had the opportunity to try it in the shop, was interested in the range and the price at 350 euro was very interesting indeed. Whilst the Tamron products are cheaper than Canon they are definitely quality products and recommended.
The following pictures were taken with the Tamron 17-50 on the first day. It was a bit overcast that day but I was very suprised at the sharpness of the lens and was quite happy I bought it.
The below images give an idea of the range of the Tamron 17-50 zoom. 17mm is quite wide and very useful on a crop camera.
The target. Camera on tripod and images produced in camera JPG fine. No further processing to below pics apart from crop at 100% and save JPG high in photoshop. All photos on this page taken with Canon 20D.
In comparison to my Tamron 28-75 2.8, the 17-50 is a more useful range for me although I miss the long end of the 28-75. It is sharper than the 28-75 but has slight distortions and perspective distortions that require some care in use at the wide end. However these can be made to work for you making the photograph more impressive once you learn how to use the lens properly. My copy of the 28-75 was less sharper and had some focusing issues. My copy of the 17-50 did not.
Flare is very well controlled. The build of the lens is plastic which is good but not up to professional standards. The autofocus makes quite a high pitched noise which some may find annoying but it does not bother me. The focusing is fast and accurate. Simply this lens is a bargain.