I managed to get hold of the older non-HSM version on eBay. It would seem to have been re-chipped to work with Canon digital SLRs (mine is a 350D). [Canon users please note: many older copies of the Sigma 300 mm f/4 and 400 mm f/5.6 only work at full aperture (fully open) with modern Canon DSLRs - don't buy off eBay unless the seller can guarantee compatibility with your model. Older copies in Minolta/Sony mount, although comparatively rare, don't suffer from this problem. I am not sure about Nikon mount versions.]
I am delighted with this lens in terms of quality and usability. I can blow up the images far more than I could with any of my previous lenses (Tamron 200-500, Sigma 120-400 OS, Sigma 50-500). It has a focus limiter, which speeds up the already quick autofocusing, is lighter than all but the Tamron, and I can get what I would consider good results of distant small birds of prey (e.g., kestrel) at f/8. Because I shoot at such range (I don't have the time or inclination to improve my fieldcraft), I find that this gives me the best sharpness. The reduced shutter speed is acceptable because I use either a shoulder-holder or a tripod and cable release.
Despite its relatively short focal length, the multiplication factor of 1.6 on a Canon DSLR makes it equivalent to 480 mm on a 35mm full-format SLR. The wider field-of-view also enables one to keep the bird in view easily. It is therefore a good lens for someone beginning bird photography (especially if interested in birds in flight) who either cannot afford or does not wish to spend 600 to 1000+ for a lens alone.
I did try it in combination with a Kenko Pro 1.4x teleconverter to give me 400 mm f/5.6 (equivalent to 672 mm on a 35 mm/full format camera). However, I found that I got better results by leaving the TC off and blowing the images up further.
The only major gripe I have is that the built-in lens hood is too short to prevent flaring, especially if one is shooting with the sun at right angles to the target.
Now, if I could only get a re-chipped 400 mm f/5.6 for around 300...
Update March 2013
The Kenko 1.4 x Teleconverter did not work reliably with my venerable 350D. (Kenko's instructions and website state it does not work with it at all.) As I do not have 400 plus spare to upgrade my lens, I have recently upgraded to a 450D body, which works reliably with the TC. I now have a poor man's 420 mm f/5.6 which works at all apertures (unlike most Canon EOS-fit Sigma 400 mm f/5.6, which only work at full aperture).
However, with the TC added, I need to stop down to f/11 to get adequate depth of field to capture birds in flight, and trying to acquire a moving peregrine over the wood at Folly Farm on Sunday was like trying to see it through a straw! Watch this space.
I am delighted with this lens in terms of quality and usability. I can blow up the images far more than I could with any of my previous lenses (Tamron 200-500, Sigma 120-400 OS, Sigma 50-500). It has a focus limiter, which speeds up the already quick autofocusing, is lighter than all but the Tamron, and I can get what I would consider good results of distant small birds of prey (e.g., kestrel) at f/8. Because I shoot at such range (I don't have the time or inclination to improve my fieldcraft), I find that this gives me the best sharpness. The reduced shutter speed is acceptable because I use either a shoulder-holder or a tripod and cable release.
Despite its relatively short focal length, the multiplication factor of 1.6 on a Canon DSLR makes it equivalent to 480 mm on a 35mm full-format SLR. The wider field-of-view also enables one to keep the bird in view easily. It is therefore a good lens for someone beginning bird photography (especially if interested in birds in flight) who either cannot afford or does not wish to spend 600 to 1000+ for a lens alone.
I did try it in combination with a Kenko Pro 1.4x teleconverter to give me 400 mm f/5.6 (equivalent to 672 mm on a 35 mm/full format camera). However, I found that I got better results by leaving the TC off and blowing the images up further.
The only major gripe I have is that the built-in lens hood is too short to prevent flaring, especially if one is shooting with the sun at right angles to the target.
Now, if I could only get a re-chipped 400 mm f/5.6 for around 300...
Update March 2013
The Kenko 1.4 x Teleconverter did not work reliably with my venerable 350D. (Kenko's instructions and website state it does not work with it at all.) As I do not have 400 plus spare to upgrade my lens, I have recently upgraded to a 450D body, which works reliably with the TC. I now have a poor man's 420 mm f/5.6 which works at all apertures (unlike most Canon EOS-fit Sigma 400 mm f/5.6, which only work at full aperture).
However, with the TC added, I need to stop down to f/11 to get adequate depth of field to capture birds in flight, and trying to acquire a moving peregrine over the wood at Folly Farm on Sunday was like trying to see it through a straw! Watch this space.