You may be thinking that the Sigma 800mm f/5.6 EX DG HSM weighs a ton but at less than 5kg, it's actually quite reasonable. That may still sound ridiculous, but this lens is not designed to be handheld. It's not only the weight but the focal length that makes this lens cumbersome.

SIGMA really needs to stop raising the price of this lens and add it's Optical Image Stabilization "O.S."I owned this lens for two years early in it's production run. I shot it mated to then new EOS 1D MkII (which gives you an idea of when I had it)New versions have come out and the price keeps...

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  Consistent Output, Durable, Fast / accurate auto-focus, Rugged, Strong Construction

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  Heavy, No Image Stabilization, Poor in Low Light

I gave a lot of thought to purchasing this lens to photograph birds. I've yet to get the beautiful kind of shots I expected from it. Mostly it is quite difficult to get in a position to use the lens to its best advantage and full capacity.

I was looking at this lens for about 1 year and finally got it. I always test the sharpness of the lens and this lens at 800mm is sharp. It is heavy, but if you have a good heavy tripod, you will get some great sharp images. A great lens but not a carry around type lens.

Excellent optically and gives unparalleled reach and ability to frame shots. Heavy and demands care in handling. Before purchase I tried 600mm f4 and could detect little difference in quality. The flexibility of the zoom made the decision on purchase easy.

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  Extreme reach, Sharp, Brilliant rotating filter system

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  Heavy (but this is unavoidable) Finish is good but not great. Attracts lots of attention. Case provided is OK for storage but not for carrying. I have a Lowepro Super Trekker which will carry this and a range of other kit.