Sigma 170-500mm f/5-6.3 Aspherical RF APO

I just bought the lens well used from a private seller at £230 (around $378 at current exchange) and tried tens shot with my Canon 20D. The photos at 170mm is quite good while 500mm is well acceptable. I picked a pine branch around 15m away at F76.3 and F7.2 and still see the spider web very clearly in hand-keep mode.

I, however, believed using tripod or monopod is a must to avoide handshaking as this is truly heavy monster. Without tripod/monopod or other supporting tool you can not make more than a few shots continuously.

Given that outdoor/wild life shooting is not something regularly and only are carried out in good weather, I still recommend to buy this lens as it is only 1/3 of the payment I paid for my Canon 300mm L USM and photo, in some certain conditions, are acceptable. Should the potential photographer is less than 170cm and 60kg weight he.she should think twice before going ahead due to its heavy weight.

Good value of money (of course can not compared with the L lens but alot better than the Cosina 400mm that I used before)

Heavy, blur photo in bad weather

Cosina 400mm, Canon 300mm L USM

None

My experience has been a bit different than most others here, as I find this lens to produce very sharp images. I use it on a Nikon D70, and shoot RAW files. I've shot mostly in the focal length range of 400mm to 500mm, still good and sharp.

It does suffer from chromatic aberration (CA) in high-contrast situations of very bright (overexposed) backgrounds with darker foreground objects, had that happen when shooting birds in trees a few times, but under most conditions, CA is negligible-to-non existent. I've used this lens mainly for nature stuff, but have also shot a couple college football games with it, and it worked great for that, sharp, great contrast, no CA.

It does demand that your technique be almost flawless. It definitely requires a sturdy tripod or monopod and ideally an f/stop in the range or f/8 to f/11 for the sharpest results. For the money, I am very happy with this lens.

Sharp images, reasonable price

Very unforgiving of less-than-perfect technique, zoom creep if the lens is pointed downward, CA in certain situations with overexposed or very bright background with darker foreground objects.

This is a good lens for what it is - a "consumer zoom". You would have to spend a lot more money to get significantly better image quality such as provided by a Canon L zoom such as the 100-400 L. It can be hand held with an appropriately high shutter speed but I find its best used with some sort of support, even if its a monopod. I find I get the best images with the lens mounted on a sturdy tripod, stopped down a bit and using a remote shutter release. I use it on my Canon DSLRs but haven't used it on my film bodies.

Zoom range, quite reasonable image quality, price - it includes a tripod ring, a hood and a carry case.

No zoom lock, filter size, though mine (used) came with a uv filter, noisy focus.

Canon 70-200 f/2.8L with 1.4x teleconverter, Canon 70-300 IS

Not needed

Useless lens. This is my second attempt to "save" money on a non-nikon lens and it has been a complete waste. I have shot with this lens on a tripod, mirror lock-up and remote trigger and still can not get an image I would even consider offering for sale.

None

not capable of producing a sharp image

Nikon 2.8 70-200mm VR

N/A

I've been dissapointed with this lens from the time I've spent going from amateur beginner photographer to semi-pro/expert. I bought it a few months after my first SLR: a film Canon Rebel 2000 (EOS 300)

It's never really produced sharp images at anything beyond 400mm. I've mainly used it for wildlife photography, originally on the Rebel 2000, then film Canon EOS30, printing to as large as A5 (at most). After I upgraded to a 20D, I really noticed the shortcomings of the lens: softness that not even Photoshop can fix.

The UV protective lens for the Sigma was not that expensive, but the circular polariser was quite expensive. Not terribly difficult to find lens filters: I phoned around in an afternoon and found some.

I've never really had focussing issues on any of the Canon cameras I've used. I simply set the focus to centrepoint and away it goes, with minimal hunting. Maybe I got lucky? Tracking focus is -however- unrelaible.

Price (for a new lens). Its a budget means of getting closer to sporting events, but not a professionals lens.

It takes great photos for postcard size prints, even up to 10x12.

Looks the business and if you accept the limitations, you can work around them. In this vein, try renting a variety of lenses before committing to buying one.

Judging from the limited successes I've had, this lens does well in photographing sports events (fast cars/F1, hockey, etc). Not so great for wildlife, unless there is full sun (which kind of defeats the purpose).

No flare that I've ever noticed (I've never really experimented much). Just use the supplied lens hood. I would however reccomend coating the inner (plastic) surface of the hood with black felt.

Price: You may get a better match with a new 100-300 lens and a second hand 500mm prime with an adapter. But you will need dedicated research and reading up on blogs to find lenses that meets your requirements.

Soft focus when aperture wide open. Admittedly, I have gone as far as using this lens on a bean bag with a remote release (never a tripod) but as far as I've been able to determine even in extremely bright sunny weather, stopped down and at 1/000th second exposure, you still get soft images.

Does not enhance the advantages offered by high res (8MP+) digital photography at anything beyond 300mm.

"Floppy" lens. It does wobble about a bit when the tube is extended. I've never fiddled to see if that significantly alters the focus.

Despite being a heavy monster, it feels plasticky. You get what you pay for.

Hopeless as a macro lens (1.5m? focal length)

I don't think this should be your first zoom lens.

Chromatic abberation abounds (at least Photoshop can fix this)

Some vignetting noticeable at long reach (500mm). Recommend using only a UV or only a circular polariser at any one time.

Using a 1.4x image extender is a hopeless excercise with this lens; don't even consider it.

Poor storage case design. Yes, you get a bag with the lens, but it's a tube (lens fits in one end of tube and you slide the lens out). I forget about the lens creep so often that I have had to put a label on the lens cap to warn me when I remove it from it's bag. If you try remove it vertically, if frequently creeps unexpectedly from 170mm to 500mm in a splitsecond. Hopeless for astrophotography with that kind of creep!

Dust specks are a problem inside the lens now. I'll have to take the lens apart to clean it. I have not had any other experience to say if it's a poor design, or if I've been unrealistic in expecting it to stand up to the beaten tracks that I travel.

Focus is loud and mechanical. Loud enough to scare timid wildlife subjects a couple of meters away. About as loud as rubbing your hands together quickly.

Recently I bought the Canon 100-400L IS USM lens. This lens is fabulous on the 20D reduced sensor size. Every bit as sharp as a L series lens claims to be. Understated genius in design. Sure, the L lens broke the bank at $1800 (I had to ship it in :s, but no more fuzzy details in images. For me, it is quite important to be able to creatively crop a poorly framed image at (say) 400mm and not have to really worry about softness ruining the resulting crop. I've managed to take some pretty amazing hand-held images in next to no light thanks to the image stabiliser. Is this lens three times better than the Sigma? Yes. If you can find one second hand for $800, then go for this rather! The L lens has made the Sigma obsolete overnight and Iit is now being sold.

My first zoom is an early 70-300mm EFII Canon lens which is much sharper in the 170-300 range compared to the Sigma lens. I will also suggest that with a high quality good lens extender (1.4x or 2x) on the 300mm zoom, I can get about as sharp an image as the Sigma lens (but with much less light entering the lens and using a 20D smaller-than-35mm CCD)

Have never sent it in. - No comment.