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Question: Which one is better Sigma F/2.8 EX DG 70 mm Macro or Canon F/2.8 100 mm Macro? I'm interested in picture quality.
Document: [[ASIN:B000GPKQHQ Sigma 70mm F/2.8 EX DG Macro Lens for Nikon Digital SLR Cameras]Prior to purchasing this lens, I did my research on macro lens, comparing technical specifications, prices and manufacturing countries. Contacting Nikon USA, the representative could not tell the manufacturing country. I had bad experience of owning a Japanese brand, made outside of Japan. Guaranteed by the manufacturer's brand name is not good enough. I like to buy and use a quality lens, not a brand name!!!!
Sigma 70mm F/2.8 EX DG Macro Lens for Nikon Digital SLR CamerasVery satisfied with the sharp photos. The autofocus works well and I like the focus limit feature as allowing the lens to search the entire focus range for each shot requires several seconds. Easy switching from manual to autofocus, but no focus touchup. I get a little vibration during focusing if the camera is held at a certain angle. Overall, for the money this is an excellent lens.
I sometimes like Sigma EX lenses and the way they feel and sometimes I don't. This 70mm macro I do. It has a nice smooth feel, is solid and has a nice weight to it and also a very handy mounting ring (like Tokina 100mm macro). This Sigma focuses accurately on my d90 and also has a nice smooth manual focus feel for an AF lens. Which by the way, is only one button (Nikon) or lever to switch to manual focus. I know this is not as good as AF-S, but at least it's not a lever on the camera body and a goofy button on the lens too!Overall the Sigma 70mm 2,8 macro is a fantastic macro lens, the working distance is a bit close (approx.
Initially I thought I bought the best lens so far. It was sharper than my 50 mm Canon f1.8 lens. Then one day while I was shooting I forgot to tighten one of the legs on my tripod. My camera with Sigma 70mm attached to it fell down on the wooden floor. The lens had the hood attached to it. So it didn't hurt any of the glass part or the front part. Strangely enough, the plastic barrel near the AF/MF focus selection button broke off and the focus selection switch fell off the lens.
If you're using it to double as a portrait lens, this one might be too big - they also make a 50mm in the same high quality EX series that might be better suited. (There's also a true 105.) The specs are outstanding - this is a very bright, high quality, low-distortion lens. Only complaint: the auto-focus can get confused in lower light situations, more so than happens with my shorter kit lens. (18-55)  But some of these shots are best handled with manual focus anyway.
The Sigma 70mm F/2.8 Macro lens is a great performer, regardless of it's low price point. This is a tack sharp lens that is also very good as a portrait lens on a cropped sensor camera. Highly recommended.
The Sigma 70mm 2.8 lens gets an excellent review at [...] for its optics and image quality, and I think the 70mm focal length works well for close-up flower photos. I returned this lens only because I found it too long and heavy to keep steady while used with my monopod for garden and wildflower shots (it weighs 1.2 pounds). I just don't find it practical to use a tripod on hikes in the hills.If I buy another marco lens I'll probably go with the Canon EF-S 60mm f/2.8 USM for my Canon EOS Rebel XSi, which is significantly lighter and shorter.
The Sigma 70 macro is particularly good on smaller format cameras due to the almost lack of veiling/fall-off due to use of lenses sweet spot. This lens is usable at f/2.8 for nice sharpness and smooth transitions (Good for portrait and close-ups). I stop to f/4-f/5.6, to clean up any aberration in high contrast situations (mostly in corners) and to sharpen up corners a bit and increase depth of field. Also stopping down increases contrast and brightness a touch but that is about it.So why four stars?
In the local high school gym, I was able to get several excellent action shots during a basketball game. The focus is really fast! I had several shots where the ref jumped in front of the camera just as I was taking the picture and every one of these bad shots was perfectly in focus. (Of course, there is nothing easier to focus on than the black and white stripes of a ref's shirt.) Overall, I'd say that this lens produces more in-focus, usable, action shots than my Nifty Fifty (Canon EF 50mm f/1.8).More on the focusing.- When you throw the focus limit switch, so that it can focus more normally, it stops focussing at 0.5m.
This makes shooting skittish insects virtually impossible, and even for stationary objects it poses a very difficult lighting problem: at only three inches away, the lens casts a shadow on the subject unless you have diffuse lighting from several angles. A ring flash may work but you would probably have to reduce its output at such a close distance.There are much better choices for dedicated macro work. I wasn't all that impressed with the Sigma 105mm f/2.8 macro, but I really like the Sigma 150mm f/2.8 Macro OS or the aforementioned Tamron 90mm f/2.8 VC Macro.
Answer: The Imaging-Resource.com used or maybe still uses the Sigma as their "reference lens" for evaluating DSLR image quality. Their website states/stated that it was the sharpest lens they ever tested.