I have the Canon 180 and when the hood is on, the effective working distance is cut even more. But there are not too many options in this category. I read one review, can't remember the site, in which the Tamron did better at lower aperture because the focus mechanism was finer. So I'm not sure how accurate that test was if manual focus was used. My preference is for lenses that render the image well in the viewfinder, often when the light is less than bright, which also means a camera with a good viewfinder is essential. Manual focus is the norm for 3D macro subjects.
I have found the Canon 180 macro focus precision is not quite what I'm used to compared to some of my former film gear. The tripod mount is essential, as well as a remote release. The Canon tripod mount is very solid. With a previous brand of digital camera and lens, the mount had too much flex for use in the macro range. Also, because of the internal focus on the Canon 180, the actual focal length at 1:1 is closer to 120mm. I'm not sure about the other lenses, but since working distance is nearly the same at 1:1, I have to conclude that they have internal focus and shorter effective focal length. I have also heard complaints about the slow auto-focus of the Canon 180 macro. I think they must not understand the issues with auto-focus, as the focus distance range is about 4x a normal lens, assuming a normal lens can to 1:4, and is why there is a focus limit switch on the Canon. Some choices not mentioned are using a telephoto with extension and possibly a 1.4x converter. With extension, you get close focus without the loss of focal length, and hence get better working distance. It would be interesting to know how the Canon 135mm + extension matches the 180 macro. Can the 135 be fitted with a tripod mount? All that extension tends to make for a more unstable system though. If anyone has a good solution for macro work + good working distance I would be very interested to hear about it. Wayne * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
