Sigma 100-300mm f/4.0 EX IF HSM APO

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.

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)

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

Never needed

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.

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.

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

NA

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.

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.

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

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.

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

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

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.

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.