> [EMAIL PROTECTED] wrote: > Is there a quick and dirty way to determine the max magnification achievable > when using Canon diopters? > For example, I say where some one said that using a 500D (+2) with a > 70-200/2.8 (.16x at 200mm) would yield a max magnification of .55X. Is > there a simple calculation to get the .55X result?
Hi Darrell, How about some elegant methods instead? Try an EF lens brochure which has the correct specs, mirrored online at: http://home.wanadoo.nl/erwin.harkink/Photo/EOSLenses.html Alternatively, browse to the lens calculator: http://members.rogers.com/jul.loke Plug in the correct values for your lens: e.g. 180mm @ 1.3m gives 0.16x and 200mm @ infinity gives 0x Adding the 500D diopter produces 0.57x at 0.36m and 0.4x at 0.5m Why 1.3m? You have to allow 0.2m for the length of the lens. Why 180mm? That's the focal length with internal focus that gives 0.16x Cheers Julian Loke * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
