Thanks to my wife, I got some nice gift certificates for Henry's Camera. I was able to pick up a Sigma 70-300 DG OS (Optical Stabilization) lens. I was looking at something not too expensive; this Sigma lens runs about $450.00, and has excellent reviews on both Amazon.com and the B&H Video site. If you accept that this is a moderately-priced 70-300mm lens designed for amatuers, you should be happy with it. I think if you start to compare it to Canon's 70-200mm f.2.8 IS II, you'll certainly find weaknesses in the Sigma by comparison, but that model of Canon lens is also about 3 times the price. There are reviews and product spec info pages on the web for this lens, so I'm not doing a big review, just a brief overview. This is my first non-Canon lens for my 7D. As far as aftermarket lenses go, Sigma is generally accepted as producing excellent product. This lens can be used with both full-frame sensors, as well as the smaller APC-s sensors, such as is found in my Canon 7D camera. In brief:
1. Overall weight and build: The lens barrel is plastic, but it has a solid feel to it. The calibrations on the lens are high resolution, matte-white on black lens, which make all of the numbers very visible. Sort of like the matte-white numbers on the dial of the famous Omega Speedmaster watch, which was used in NASA's space program owing to it's legibility under different light sources, among other things. So, I like the very legible calibrations. I like that the lens is not a heavyweight, and wears comfortably on my Canon 7D. It also comes with a lens hood, which has a very matte finish, in order to diffuse light I would think, which is a clever thought by Sigma engineers. What I really miss is a barrel lock; I have not found there to be any lens creep as its called (the lens slowly extending itself owing to gravity as it hangs from at your side), but I have read that in time, the barrel will develop lens creep. All telephoto zoom lenses should come with a simple lens lock, which lock the lens at its shortest focal length, so the lens doesn't drop out while you're trekking about.
2. Auto focus operation: The auto focus is to my perception, a noisier affair than the AF on my Canon lenses. I have read complaints of slowness in the auto focus on other reviews, although I have not yet found this to be the case. I have found the auto focus to be acceptably quick and on target in use.
3. Lens speed. This is not a super-fast lens. In other words, if you want to use this lens to take exposures of fast-action (think sports) in less-than-bright light, you may find it is not fast enough since its widest aperture is f/4-5.6, with the tightest aperture being f/22. In the series of exposures I show here, the fastest I could shoot at 300mm and f/6.3 (the widest aperture I could use with an acceptable shutter speed for some light morning dog-walking action) was 1/100 sec, not fast enough to freeze motion. To be fair, the light was grey and overcast.
4. Sharpness at wide open lens: When I took an exposure of a still subject at 300mm, I found when I zoomed the image 100%, the image detail and sharpness was acceptable. I have read that the sweet spot for image sharpness at 300mm for this lens is closer to f/9, but I couldn't manage it in the light this morning.
5. Color sharpness: When set correctly (I shoot in manual mode all the time, so I try to balance aperture and shutter speed based on my camera's readings moment by moment), I feel that the colors seen in the images I posted here, as well as in the images I've been test shooting since I got this lens, are sharp and correct.
Overall, this is a decent lens for the money. I have read pretty much only positive reviews of this lens. Its prime uses would be for wildlife photography (the main reason I bought this), sports action from the sidelines in good light, and portraiture work, since the 9-blade aperture construction creates some very pleasing bokeh. I look forward to posting more images from this lens in the future.
A few test images; the test images are as shot, with no correction post-production. These were only re-sized to be able to be uploaded.
Photo 1: Lens zoomed out to 300mm; reviewers say that the best aperture for this lens at 300mm is about f/9, but I could not do this in the grey-sky light today. My aperture setting was f/6.3, and the fastest shutter I could get at ISO 200 was 1/100, not fast enough to freeze the action of a running subject.
Photo 2: Cropped section of the moving image, zoomed 100%. The distortion is due to the low shutter speed.
Photo 3: Lens zoomed out to 300mm, f/6.3. On a still subject the sharpness, I believe, is very good. Color here is excellent as well.
Photo 4: Cropped section of the still image, zoomed to 100%. Sharp detail and color in my opinion.
Photo 5. Shot to demonstrate the bokeh of this lens; here, the foreground in blurred, the background fence is in focus.
Photo 6: Opposite; the foreground in focus, the background fence in blur. This should be a really good portrait lens.
Chris Kiez, a hardcore photographer since the 80's, learned to take a picture before the age of selfies and cell phone photography, training on mechanical cameras and film. After years of taking photos of all manner of subjects and people, he did over a 10 year stint as a crime scene photographer on two continents. Now, he does portrait and landscape photos, and is currently distressing the world with his relentlessly, excruciatingly boring blogging. To buy what you see on this site, click here!