> There is an article where the author did some tests and found that 2-element diopter >lenses produce better quality images than do extension tubes. > > http://people.smu.edu/rmonagha/mf/diopter.html > > There is a rebuttal to the test on the same page, so opinions may still vary. >Personally, I plan to buy diopters but only because I would be using it on a zoom >lens and I have read John Shawn and others state that zoom+extension = hard-to-use
Good point. I tend to forget that when I use the extension tubes with the 70-200/2.8, I tend to focus using the ZOOM ring, not the distance ring. Also, I think I neglected to point out that single-element diopter lenses should probably be avoided. I did mention the 500D, which is a 2-element lens (D for dual or double, I think). Lars -- Lars Michael [EMAIL PROTECTED] 87GT http://www.larsmichael.com/ * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
