On Thu, Jul 21, 2005 at 05:18:01PM -0700, Shel Belinkoff wrote: > Hi Rob ... > > The original thread went off on DoF. As you said, the original issue was > whether or not there was any difference in AOV or perspective. All else > was irrelevant to me when first posting the question, and, while the DoF > issue may be of some interest to some people here, it's not to me. Anyway, > I wouldn't know how to design a test for that ... that's more in your > bailiwick ;-)) > > I'm more interested right now in another aspect of this. Early on I noted > that the image seen through the istDs finder looked smaller and seemed > "further away" than the image seen through the SLR I was using. I believe > it was John Francis who said any perceived difference would be the result > of different viewfinder magnifications. OK, I'll accept that. But ... the > view of the scene through the istDs finder showed things to be smaller and > further way. Both of us commented on that on Saturday when we were > conducting this test. However, the magnification of the istDs viewfinder, > according to Boz's site, is .95 and the % of view is 95%. The K-body > camera has a .88 magnification @ 93%. It would seem that the view through > the finder would appear closer, or larger, when using the istDs. What's up > with that?
That's because viewfinder magnification is always quoted with a 50mm lens. If you instead look at the *ist-Ds magnification with a 33mm lens (which gives you the same AOV as a 50mm lens on the film SLR) you end up with a mere 63%, far smaller than the 0.88 you got from your K-body. Or, to put it another way - the magnification of the image you see through the viewfinder of the *ist-Ds with that 18mm lens mounted is larger than you would see through the K-body with the same 18mm lens attached, but not as large as you saw through the K-body with the AOV-equivalent 28mm lens.
