> Does anyone have any opinions about the Sigma 105mm f/2.8 EX Macro >lens?
Here is a review, partially extracted, from my www.CameraHacker.com site: "The auto-focus speed is extremely slow, compared to Canon's USM. However, speed is decent if you set the focus limiter to either normal or macro range. I am also using it with a Rebel G, which probably have the slowest AF capability. Generally I only use this lens for macro, and I find AF to be somewhat useless. AF is especially useless on semi-transparent objects. Since DOF is short, the lens can either focus on the internal organs, or transparent exterior of the object. The lens can't decide in this situation, and I'm generally unsatisified with its choice. In fact, a lot of the time in macro work, you set the ratio and focus the subject by moving the lens back and forth. The lens is very solid and sturdy, yet not very heavy. Focus ring has full throw, rather than the very short throws on zoom lens, which may be why AF is slow. Manual focus is smooth with no play. Resistance is just right for my taste. A clutch disengages the focus ring, so that you may hold the very large and comfortable ring while auto-focus. Personally, I feel the lens is very sharp, as indicated on Photodo. I tested the lens out on some portraits shots and found the resulting photos to be way too sharp for portrait work. Which is unfortunate, since I was hoping on using this lens for both macro and portrait. Perhaps a UV filter or diffuser would help. This is a great 105mm lens if you need extreme shareness. This is an extremely sharp macro lens that is capable of 1:1 ratio. I use it to get close-up of flowers, insects, and other tiny objects. Some of the lens pictures that I took myself on this web-site are also taken with this lens, because other lens can not focus close enough. (See photo section below.) Distance scale is provided. Macro ratio scale is also provided on the lens barrel. The 2.8 f-stop is also very nice for speed and background blur. Filter thread is 58mm. Lens hood is metal, included, and screw-on type, non-flower shape. The lens has a non-rotating front. The lens include a semi-soft padded carrying case that can be strapped onto your belt. This lens costed me about $360 from B&H. But I feel that it is money worth spent." -- Chieh's Web - http://Chieh.CameraHacker.com/ * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
