Last week I was faced with the hard decision to choose a new zoom lens for use with my Canon 50D body. The following lenses were within my budget:

• Canon EF 70-200mm f/4.0 L IS USM
• Canon EF 70-200mm f/2.8 L USM
• Sigma 70-200mm f/2.8 DG HSM II Macro
• Tamron 70-200mm f/2.8 Di Macro

I did some research and found that the in-depth reviews by dpreview.com was pretty helpful for getting a in-depth review of some of the candidates under consideration. However, they only had tests for the Sigma and the Tamron lens on my short list. Further, they did an in-depth review of the image stabilized and much more expensive version of the Canon EF 70-200mm f/2.8 L USM so that was close enough. Interestingly enough none of the three reviews were conclusive for me as they all revealed some less nice shortcomings. There are more Web sites out there which cover all of them though. For example take a look at the-digital-picture.com.

For example, it seemed that the Tamron lens did very well on the lens and image quality side (including sharpness) but fell very short on its focssing system (speed and reliability). I confirmed that when testing in a professional photo shop in downtown Sydney on Friday. The lens was by far the sharpest one among my candidates but the focussing system was much less impressive. It seemed to hunt forever and the motor was very loud and moved slow. Especially in comparison to the two Canon L series lenses. Another deciding factor against this lens was its weight, for my purpose it was just too clunky and heavy. My wife even had trouble lifting it at all.

The Sigma lens has much better focussing capabilities but there were some doubts about image quality and sharpness in particular. Further from reading some of the lens reviews posted at amazon.com it seems that you need a little luck with the lens sent to you as Sigma’s quality control is not very impressive. Reading about people sending back several lenses before they got a usable one is somewhat frightening. Especially when I wanted to do my purchase one day before leaving into a holiday. So this one was quickly off the list too.

Finally the decision was to be made between the two Canon L series lenses. Since both are roughly in the same price range where one offers a much better maximum aperture of 2.8 and the other offers an image stabilizator at about half the weight I was quite torn between them. My visit to the shop and doing some shots did help a lot there. The Canon EF 70-200mm f/2.8 L USM was really heavy, especially with the tripod mount attached – a less desirable feature if you do a lot of travelling and bush walking as we do. Also, in terms of sharpness with an aperture of 2.8 it was less impressive. This was in line with the review at dpreview.com which made similar comments, especially on non full-frame bodies. The Canon 50D has a crop factor of 1.6 which gives the lens an impressive 320mm maximum zoom compared to a full frame body such as the 5D Mark II or the 1D series bodies.

Given the much better handling of the Canon EF 70-200mm f/4 L IS USM lens with its (only!) 750 gr weight and a nicely performing image stabilizator (note, this compensates only for hand-shake) I decided for this model. Also, it made the sharpest photos in the store right after the Tamron lens. Since this was one of my main criteria I am happy to have found a lens wich seems to perform very well for an ambitious amateur like me while still being light enough to not requiring me to carry a monopod or tripod around all the time. The impressively performing image stabilizer which gives me an extra 3-4 stops adds to the good performance of this lens.

I will be posting a few articles about my first experiences with this lens in the next few weeks. Stay tuned!