Fast and long...
 

Looking for some opinions on fast long(ish) lenses and wondering if anyone had any experience.

I am looking for the best way to get to 300mm f2.8. The options as I see them are a Sigma 120-300 f2.8 OS, a Sigma 300 f2.8 prime or a Canon 300 f2.8. Has anyone used one or more of these lenses and care to offer some thoughts on it.

I had a Sigma120-300 briefly when I had a camera from the dark side but that was before they made an OS version. I seem to recall then that it was generally rated higher than the Sigma prime and it certainly offers more flexibility. I was very happy with it but had no experience of anything else.

Sigma have always had a bit of a reputation for less than perfect consistancy where as with the Canon you know what you'll get - but then you get what you pay for and there is a £3.5K difference to consider.

If Sigma made a 120-300 in 4/3rds I would have it like a shot but in the mean time I am waiting for a spare £6k to float past for the Oly prime :D

Thanks for the feedback Nigel. I've had a 120-300 in the past too and was pleased with it optically however the lack of stabilisation left me unable to shot it handheld. To get decent shots handheld I needed very fast shutter speeds (well above what I would have expected) so I ended up using it on a tripod which wasn't what I wanted. I was looking for a lighter set up than my 500 f4 that I could use with out a tripod so I could have it with me a times when the 500 and tripod was impractical. I sold it on here and I believe the chap who bought it had a similar experience. A while ago I got offered one at £1k new with the 3 year warranty and decided to give it another try. However when I tested it I was disappointed to find that it was very soft and lacking in contrast and had to be stopped down a long way to get useable results, my 300 f4 was so much better. I have read that the OS is much better but don't know how close it gets to the Canon.

I've now had a chance to have a quick play with a 120-300 OS alongside a 300 f2.8 IS and wasn't too shocked that the Canon came out on top. S a quick comparison in case others were wondering...

The Sigma does feel well built and the plastic lens hood feels a lot more solid than I had expected. Both the focus ring and the zoom ring were smooth with a nice level of resistance and the lens felt good for handholding. The OS seems to be quite effective as I was able to handhold it at 300mm 1/50th and still get good results. The Canon looks like a bigger lens though there is little difference in size and the Sigma is slightly heavier. The Canon is also very well made and feels great in the hand, the IS is also very effective. One thing that was instantly obvious when testing them was the fact that the Sigma comes up well short of 300mm when shooting at close range (a common feature of zooms but I was surprised at now noticeable it was). For me this is a big issue as I will be using the lens for wildlife and the shorter focal length would be exaggerated when using with tcs. Then on to the real test how sharp they are at f2.8. I was very impressed by the Sigma, on a very basic test shot it showed good sharpness and contrast. It was significantly better than even he best non-OS version that I have used. Again as expected the Canon was even better, sharper better contrast and colour rendition. This was a mkI Canon so sells for about twice what the Signa does but probably isn't twice the lens. The bottom line for me is that as expected the Canon wins out in just about every area, only lacking in the versatility of the Sigma. However the Sima preformed better than I expected and I reckon I would be very happy to shoot with one, but there is no doubt in my mind that the Canon is worth the extra if funds allow.