Bob Talbot cited: > http://medfmt.8k.com/third/af.html
Correct me if I'm wrong, but if the cited article (in October 1995 Pop Photo) is the one that I recall (and it's been a while ...), manual focusing was done by using a loupe on a ground glass placed on the film rails ... I never could figure how to do this with film in the camera. I think that article also reported that MF achieved through the viewfinder wasn't as accurate as that on the groundglass, either. I don't recall how through-the-viewfinder MF compared with AF. In the days before AF, the accuracy of the focusing screen was one of the items reported in camera reviews. As I recall, anything within the lens's depth of focus was considered acceptable. Different is never quite the same ... and in some cases, it may not even be equivalent. As the web page indicated above mentions, it's difficult to compare MF using a current AF camera to MF on a manual camera. The focusing screens on most current AF cameras exhibit less contrast that those used on MF cameras, so that the subject doesn't snap in and out of focus on the AF camera as well as it did with most MF cameras. Moreover, there aren't many AF cameras that include a manual focusing aid such as a split image or microprism; in most cases, I found these things annoying, but it some cases they made it easier to achieve sharp focus. I've also found it much harder to get fine MF focus control with any AF lens that I've tried (Canon and Nikon) than with most MF lenses. Of course, it's often difficult to make a direct comparison. The best I've done was with a 105 mm f/2.8 Micro-Nikkor and a 105 mm f/2.8 AF Micro-Nikkor; the difference in the ease of MF was considerable. With Canon, similar comparisons can be made between any of the TS-E lenses and EF lenses of comparable focal length. My impression with these comparisons is about the same as it was with the MF and AF Micro-Nikkors. My experience with the Canon focus confirmation indicator is the same as that of several other posters--it indicates correct focus over a small range of distances. It's obviously not correct, but the alternative (with a very precise in-focus indication) sometimes makes it very difficult to ever get focus confirmation. As I recall, the early Nikon focus confirmation indicators (especially in the F4) were a bit fussier than the Canon. The F4 had arrows on either side of the focus-confirmation LED that showed the direction in which focus was off; without these arrows, I'd have found it difficult to get the focus spot on. I've never made a rigorous comparison between AF and MF with EF lenses, but in most cases, AF seems to be as consistent (and much faster) than I can get by eye. I'll concede, of course, that my eyes may not be what they once were ... Jeff Conrad * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
