Hi,
as mentioned above it's myself that uses one
, only bought last month and not had much chance to use it so far but I can say that it resolves details that the 100-400 Canon misses.
Recent posts with samples include these - earliest attempts first and so on:
BLUE TITS
DUNNOCK
SWANS
ROBIN
Ok don't get me wrong if I HAD the money it would be a Canon 500 F4 L IS, but I don't so it had to be the Sigma, it was S/H and only cost me £1550, a huge saving even over the used price of a Canon IF you can find one, however after trying it out the first few days it arrived I thought I'd done the wrong thing with buying it. I tested it for a few days as I had a week to try it and return if I didn't want to keep it, with only getting to use it twice in that week I took and chance and kept it. In the next couple of weeks I tried and tried again to get decent shots with it but failed, not miserably but shots were average, I perservered and eventually discovered that my Canon 30D was setup up as neutral with no in camera sharpening, and comparing it against my dad's 30D it was definitely noticeable that HIS was sharper using my 500mm, it wasn't until later the next day that I realised what was wrong. My dad's was set to Standard, mine wasn't.
The first shots taken after setting the 30D to standard ( which gives 2 in the sharpening and 0 for everything else ) were the ones of the Blue Tits and Dunnock linked above. It is half the weight of the Canon and it's black which I also like. I now feel comfortable with it and think/know it's miles better than the Canon 100-400 that I owned previously. I saw one somewhere S/H the other day for around £1899 but I think it was in a bit better nick than mine which is suffering from the usual peeling/rubbing of the black coating.
If you want to save a pile of cash and are prepared to learn how to use it then the Sigma is a bargain, however if you can afford it and want/like IS then it has to be the Canon. The shots above of the Blue Tits and Dunnock were tripod mounted, the Swans and Robin were from a monopod.
One other thing it makes you think of your framing, today I tried to take shots of Pinkfeet geese out the car window and at 20 metres away I could only just get them in. Also the DOF at minimum focus distance of 4m is only 5mm at F4.5
if you wanted to get a small garden bird fully in focus at 4m then you would need around F22, and even at that it only gives you about 75mm DOF.
Don't hestitate to get back to me with any other questions or info required.
For further reading try
HERE, probably the thread that convinced me to buy it
Mike.
