I'm planning to try out reversing a lens for macro work. I'm interested in getting approximately 3x magnification. I thought that this technique worked by mounting a second lens reversed on the front of the first lens, giving a magnification equal to the focal length of the main lens divided by that of the reversed lens (50mm reversed on 200mm lens gives 4x magnification).
But when I looked on the web for reversing rings, I found a lot of items for sale that are specific to a particular mount. For example, on the B&H site, under the macro accessories section, "Reverse adapter Canon to 52mm". But shouldn't these things be generic, as it simply involves connecting the fronts of the lenses via a ring with a screw thread on each side? Or have I misunderstood the technique? I'm also wondering which lens to use. I have three reasonably long lenses: 180mm macro, 100-400 IS, and 75-300 IS. If I understand the technique correctly, I'll have to use the 75-300 (which would not have been my first choice) because the reversed lens must have a diameter at least equal to that of the main lens in order to avoid vignetting. So either I use the 75-300 (58mm filters), or I have to find a short lens with a wide body (72mm and 77mm filters respectively for the other two lenses). Can I use an EOS lens as the reversed lens? It has to be wide open, so I guess there's no problem (can't be controlled electronically, as it's reversed). I was thinking that I might reverse my EF 50mm f/1.8 on the end of the 75-300mm lens, to give a 1.5x-6x macro combination. I don't mind buying a non-EOS lens to reverse on the end of my EOS lens, but I'm trying to do this reasonably cheaply (in other words, buying the MP-E 65mm macro lens is not an option at the moment). Gerry * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
