I wrote: > Correct me if I'm wrong, but if the cited article (in October 1995 Pop > Photo) is the one that I recall ... manual focusing was done by using a > loupe on a ground glass placed on the film rails ...
Bob Talbot replied: > Well, rather than focus on the part of the article that don't apply to > EOS ... Why would this not apply to EOS? I simply suggested that MF using a ground glass in the film plane isn't a practical basis for an MF vs. AF comparison because it's not a technique you can use in picture-taking situations with an SLR, EOS or otherwise. In any event, as it turn out, neither of the Pop Photo articles cited by Robert Monaghan isn't the one I recalled, so my comment wasn't directly relevant. > ... you could try ... Why You Can't Rely on Autofocus "in-focus" > Indicators when using Manual Focus Modes on AF: I think I agreed with everyone else on the limitations of the "in-focus" indicators, which is what started this thread. I further suggested that simply having the indicator illuminate over a much shorter distance isn't necessarily the solution. > With MF the focus "position" of the lens is almost exactly the same no > matter how many times I repeat it. I can't argue with this technique--years ago, the Nikon School used to recommend it as a periodic check of focusing accuracy (precision doesn't ensure accuracy, but lack of precision strongly suggests that you have neither). I made a habit of doing this, especially because I've used a grid in almost every camera that I've owned, and have had to rely on groundglass focusing rather than split images or microprisms. I've retained this habit since switching to AF. > With AF the "position" has a marked random element. In general, this hasn't been my experience (at least with an EOS-1n and an EOS-1v). Interestingly enough, the September 1999 Pop Photo article seemed to reach the same conclusion! As always, YMMV ... I don't by any means suggest that AF is perfect, but I do think some authors go off on tangents in pointing out its shortcomings. The magazine article that used the film-plane groundglass as its MF standard was one, and to an extent, the September 1999 Pop Photo article was another: a sidebar noted AF inconsistencies that became visible at 45x magnification-- I don't dispute the results, but how in the world can anyone do a 45x magnification in the viewfinder when using MF? I actually agree with many of Monaghan's conclusions, especially the implication that if you really prefer MF, you're better off with an MF camera and MF lenses. However, I don't share his universal disdain for AF. Jeff Conrad * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
