Build quality & finish, speed and sharpness. Internal focus, no rotating front-end, so the use of polarizers and chroma filters is no problem - if you can find any to fit the huge 82 mm filter thread (my Cokins surely don't).
Of course it's HEAVY, but it's also quite well balanced on all my cameras except the D40 (for obvious reasons).

Chromatic aberration and purple fringing on some occasions, especially wide open. This is not a mayor problem at all, and can be easily corrected in post. On the Nikon D300 and D700 this can even be done in-camera (but only for JPG, unfortunately)
Tripod socket is by far the weakest design element of this lens. I would suggest anybody who owns it to get the better, longer TS-41 model, which includes a shoulder strap (yes a bit of an investment @ 135 US - but worth it)

I bought this lens to replace my AI-S 100-300 mm. f/5.6 Nikkor. Nikon currently does not offer any lens in this range, and the 200-400 or a 300 or 400 mm. prime costs at least 5K.

I decided on this lens based on the user ratings and great review it had at photozone.de, and have not regretted it for a minute; in fact, my buying decisions from then on have always balanced in this site's ratings and I've never gone wrong.

This lens is SHARP, even wide open. Sweet spot comes early on, around f/8 and - on the right camera - it is blistering fast. Some people have said this lens is not that fast, but on my Nikon D1x, D200 it focuses instantaneously (as fast as my AF-S 17-35 f/2.8D Nikkor); and is still reasonable fast on my D40, on which I can use it thanks to HSM.

Customer Service

Never needed

Similar Products Used:

AI-S 100-300 mm. f/5.6 Nikkor

Build, AF speed, constant f4, included tripod ring and case. Image quality is on a par with my L series lenses as well.

WEIGHT. Yeah, I knew how much it would be going in and I've carried 12-14 pounds of glass around in a 70-200, 100-400, 24-105 and 180 macro before, but it's still a lot of weight.
The biggest negative is a lack of IS/OS/VR type stabilization. With a focal length of 300mm and 3lbs, some form of VR would be nice. Naturally, cost would increase too.

As part of my move from Canon to Nikon, I wanted to replace the Canon 100-400/4.5-5.6L IS I had recently sold. Honestly, there is no replacing that lens in the Nikon mount. That said, I went through the usual suspects and finally found the Sigma 100-300/4.
The lens is the only zoom in a Nikon mount that offers the range it does - period. If you include the host of 70-300's, it's the only one to offer a constant f4 at all focal lengths. Thus, there aren't really any direct competitors.
When you first pull it out of the box, you realize what a substantial piece of gear this is. On a par with my set of Canon L's, for sure - at least as far as weight and build quality goes. A huge petal hood, tripod ring and nice padded case are included. So is the trademark EX lens coat - a nice black crinkle finish.
Along with the EX mark and constant f4 is the HSM focusing motor - no body focusing here. Pretty quick, although I might hazard a guess that the 100-400 was just a tad quicker. Still, it kept up with a RedTail hawk as it flew amongst the tree branches.
IQ is very nice and balanced. Great contrast and color.
All in all, an excellent buy for less than $1000 new and $700 used.

Customer Service

NA

Similar Products Used:

Canon 100-400, Sigma 70-300, Tamron 70-200.

Ability, aperture, manual focus override without flicking a switch, build and price.

no image stabalisation if that's your bag.

Wow! This lens is bang on the bucks! It's significantly better than lower priced lenses and produces superb results. For a serious photographer, you would have to go some way in justifying another £1000 for an L lens. I'm not a fan of image stabalisation lenses as I use this predominately for fast moving subjects. The autofocus is not ultra fast, but think that is down to my 2 year old EOS 300D rather than the lens.

The weight and size means it's not something you would carry round your neck as a 'touist', but that's not the point with this lens. The hood is great as it is very long and certainly cuts out flare. Some people have moaned about the inability to easily take the lens cap on and off with the hood on, but I find it no problem as it's quick to take on and off and the lens itself is well protected with the hood on without a lens cap. Great lens.

Lighter, cheaper and more portable than 300 f/2.8 primes and zooms. Weighs, measures and costs about the same as the Nikkor 300 f/4 AF-S, but is more versatile because of the zoom, and not much worse optically. Optically far better than the cheap 70-300 zooms currently pushed by most manufacturers. Internal focusing and zooming means the lens length is constant and dust has a lesser chance to enter the lens and camera body. Lens collar is reasonably rigid, and removable for hand holding. The lens balances well on a tripod with a medium to light weight body. Fits in most medium-sized backpacks without unmounting the camera body (but you must take off the lens shade). Autofocus is fast and silent, even in less than optimal light conditions.

Twice as heavy, long and expensive as typical (but significantly worse) 70-300 zooms. No way to connect a strap to the lens (it is quite heavy, and puts a strain on the camera body and camera strap). I am looking into ways to add a strap eyelet to the lens collar. Probably you should do this too if you are going to walk a lot with this lens hanging around your neck. The original lens cap cannot be removed when the lens shade is mounted. I bought a third-party butterfly-type cap to solve this problem (I did not find 82 mm butterfly Nikon caps). No VR. Autofocus performs poorly with Tamron teleconverters on a Nikon D70s (it works effectively as AF-C even when the camera body is set to AF-S). You should use Sigma teleconverters with this lens. This seems to be a common problem with Sigma HSM lenses and Tamron teleconverters.

I needed a prime or zoom in the 300-400 mm maximum range to use mainly handheld for birds and wildlife, and I already have a 300 f/2.8 prime that makes my arms ache when handheld for more than fifteen seconds, and a lightweight Nikkor 70-300 G that simply does not cut it. I gradually narrowed down my choices to the Nikkor 300 f/4 AFS or the Sigma 100-300 Apo EX DG HSM for a number of reasons, and ended up with the latter and a matching Sigma Apo tele converter 1.4x EX DG. After making tests with a Nikon D70s, SB-800 flash with flash extender (to eliminate camera shake) and subjects at 2.5 to 10 m (which is the most useful range for me, and also eliminates the effects of air turbulence), I reached the following qualitative conclusions, which I use as a guideline for my own shooting: Lens alone at 300 mm: good at f/4-5.6, excellent at f/8-22, good at f/32. Lens at 300 mm + 1.4x TC: visibly degraded at f/5.6-8, good at f/11-16, acceptable at f/22, visibly degraded at f/32-45. The stops are indicated as reported to the camera, i.e., f/5.6 with TC corresponds to f/4 without TC. Lens alone at 200 mm: excellent at f/4-22, acceptable at f/32. Lens alone at 100 mm: excellent at f/4-16, acceptable at f/22-32. Although side-by-side comparisons show differences within the range I indicate as excellent, these differences are too small to take into account in my practical shooting. In my own experience of practical shooting, without TC this lens at 300 mm is about as sharp as my Tamron 300 f/2.8 ED, slightly less sharp than the Nikkor 300 f/4 AF-S, and much sharper than the cheap Nikkor 70-300 G. Around 180 mm, it is slightly less sharp than the Sigma Apo Macro 180 mm f/3.5, but not enough to really matter unless I need very fine detail. The Sigma 100-300 with Sigma 1.4x Apo EX DG teleconverter at 300 mm is somewhat sharper than the Tamron 300 f/2.8 with Kenko 1.4x teleconverter (the latest & best model, I forgot the name of this TC). It is optically better than other Sigma zooms like the 135-400 and 170-500 when used without a TC. It may become comparable in quality to (albeit faster than) these zooms when coupled with the 1.4x teleconverter, but I have made no extensive testing. In conclusion, the Sigma 100-300 f/4 Apo EX DG HSM is a reasonably sharp lens at its maximum range, although not exceptionally so. It performs better at shorter focal lengths, but of course this is not why you would want to buy this model. There are plenty of good 70-200 zooms out there, but not many ones that reach 300 or 400 mm with acceptable quality and speed, and the Sigma 100-300 fits this bill without being too heavy or prohibitively expensive for an non-pro. Contrast and color saturation are fine. Flare is not a problem. Mechanical construction is solid without being too heavy. I did not regret its purchase, and it is my main birding lens for handheld shooting.

Similar Products Used:

Tamron 300 f/2.8, Tamron 300 f/4, Nikon 300 f/4, Nikon 70-300 G, Sigma 180 f/3.5

Optics, HSM. build quality and price compared to OEM glass. Find these days virtually no post processing required....

Heavy and IS would be great Sigma

Terrific lens highly recommended - having upgraded from the 70-300 APO which itself was great value this lens just exposes the difference between quality and consumer glass. HSM also contributes greatly to overall capability. Have also used extensively with 1.4X teleconverter with really good results. Originally tried the 70-200 2.8 with 2X converter but found this combination less effective.

Similar Products Used:

Sigma 70 - 300 APO Vivitar 100 - 400 series 1 Sigma 170 - 500

Sharp, fast focusing and good range. Went for long hikes with this lens with no problems.

Focus hunting on the rare occation... usually not a problem but sometimes it was a bit annoying.

Used this with an F5 and got great results. The lens was very sharp and the magnification range was very usable. For those times when I needed a little extra reach the 1.4x APO TC from Sigma was a fine match, with most of pictures being indestinguishable from those take by the lens alone. The HSM was spot on and even focused in fairly low light (though if the lens didnt fine focus right away (Which was rare) then it hunted through the full focus range (which was a bit annoying). This was just about the only problem that I had with the lens and it was a very small/rare one at that. I sold the lens only b/c I just switched to canon for digital and am considering picking it up again for the EOS.

Price Sharp images especally at f/5.6 and above Solid build Excellent autofocus (fast and silent does not hunt unless very low light) Constant f/4 Fixed length when you zoom in and out (doesn't suck in dirt that can get on your sensor) Full time manual focus (you can use the manual focus while in autofocus mode)

Minor CA (purple fringing)

Over all this is an excellent lens. I am using it on a Canon 20D The first copy of my lens was horrible. It was so bad that it wouldn't give a usable image until it was stopped down to f/8. I sent it back to Sigma 4 Less and they sent me a replacement. The replacement lens is great. It produces acceptable images at 300mm f/4 and very sharp from f/5.6 and up. The mechanics are great and the build is solid. The auto focus is very fast. I can easily track birds in flight. I sold my Sigma 70-200 f/2.8 .because I needed the reach. If you don't need the reach get the 70-200 it is sharper and you can shoot a f/2.8. If you need a lens for wildlife get the 100-300. It works well with the 1.4x teleconverter. It doesn't change length when you zoom and has full time manual focus. It is a little heavy but that is to be expected with a lens that is built like a tank. At 300mm a monopod is a good Idea with shutter speeds below 1250 P.S. If you are looking to buy one, try to get one that is not the new DG version. Camera sensors are getting larger in size and in a few years the DG won't work for the full size sensors.

Customer Service

N/A

Similar Products Used:

Sigma 70-200mm f/2.8 EX APO IF HSM (the best lens I have ever had) Sigma 70-300mm f/4 5.6 macro (piece of junk) Canon 24-70L (good but not great, heavy expensive and not as sharp as the $400 sigma) Sigma 18-50mm f/2.8 EX DG (Great lens! sharper images than the Canon 24-70L and light as a feather) Sigma 17-35mm EX DG HSM (soft all the way to f/8) Canon 17-85mm IS USM (a good all around lens) Canon 10-22 EF-S (sharp and lots of fun) Sigma 24-135 (Good images but very very loud autofocus)

Build quality. Image quality wide open at all lengths. Contrast & resolution. good focus speed & lock. tripod mount. carry bag & lens hood.

Sigma lens cap. Wieghty for some. Bit pricey for what it is.

Excellent performer. Strong image quality even wide open at all lengths. A touch soft at 300mm but like it's other minor faults, you have to pixel peep to see it. I didn't notice any distortions at any enlargement. Personally, I don't have a problem with the weight of this lens. (lucky me) Overall this is a great lens. If you can handle the weight then you will never ever want another 300mm zoomer ever again. Stick OS onto this lens sigma, please.

Customer Service

Unknown.

Similar Products Used:

Canon 70-200 F4. Canon 75-300 IS usm. Canon 90-300 usm. Minolta 100-300.

build speed high quality reasults value for money

weight the nice case supplied will not accomadate an attached tele-extender

For a long time I planned on adding a Nikon 70-200 2.8 VR to my camera bag. But ultimatly I decided that it was too expensive and too short for my needs. I then considered the Nikon 300 f4. I found it the import version available for a little over $900. But I really wanted the versatility of a zoom so I started to look at 3rd party lenses. The Sigma 100-300 f4 fills my needs perfectly. I got my Sigma with the Sigma 1.4 tele-extender for about the same price as the Nikon prime alone. It is hard to believe the Nikon could give me any better images than I am getting with my Sigma. This is my favorite lens now. Images are tack sharp and colorful with amazing bokeh. This lens focuses instantly with my Nikon D70 at f4 and is useable, admitably with some hunting, at 5.6 with the tele-extender. Build quality is wonderful. This is a beautiful lens! On the down side it is rather heavy and I would not recomend using it handheld. A good tripod is a must for best reasults.

Customer Service

not used but only 1 yr warranty

build quality great lens hood nice images sigma makes one, nikon doesn't price

lens to body mount looseness, especially with TC attached

i was looking for a zoom lens that was packable on long hikes, but had good performance as well. after months of research and comparisons between zooms and primes, nikon and 3rd parties i choose the sigma 100-300 f/4 for the extra range. nikon needs to make this lens. anyway, after using it for a week i have an opinion of it. my first impression is that it's heavier than i expected(i'm glad i didn't buy the 120-300 f/2.8). i got used to it pretty quickly though. it focuses very quickly and accurately as long as you're using proper technique. the opportunities i missed were my fault not the lens'. i must say i was PLEASANTLY surprised how well it focuses in very low light. i was shooting coyotes last night in near dark conditions and it performed quite well. the images are sharp with proper technique even with the 1.4x teleconverter. that brings me to the only thing i don't like about it. when mounted on my d70 or d1h the lens has a tiny bit of looseness, but with the 1.4x it is much too loose for my liking....enough to make a straight horizon crooked if you shift the body without realizing it. if you're looking for a sharp, quick-focusing tele-zoom that makes images to satisfy all but the most discriminating photographer, buy this one...you'll be very happy.

Customer Service

hopefully won't need it