viewfinder specifications: how do they work?
ok, i suppose i could wait until the D200s are in stores to look for myself, but i'm impatient. i only know that the D200 viewfinder is bigger than that on the D2X, and the numbers that've been posted in various reviews. so i'm trying to figure out what the numbers mean. sounds to me that when a 50mm 1.4 is mounted and focused at infinity, the image that one sees in the viewfinder at the specified eyepoint is ??x the size that one sees the same view eyes unaided. is this right? if so, is it reasonable to compare the viewfinder size between film cameras and the D200 by factoring the 1.5x crop factor? so in the case of the D200 the spec is 0.94x (can't remember). factor in the crop and that's about 0.63x. that still makes it smaller than film cameras such as the F80 at 0.75x. is this correct?
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#1. "RE: viewfinder specifications: how do they work?" | In response to Reply # 0BJNicholls Charter MemberFri 04-Nov-05 11:29 PM
A 1.0 viewfinder magnification would mean that you could open both eyes and the apparent scale of the viewfinder image would match what your other eye sees directly. Decades ago it was deemed important to provide a 1.0 (or nearly) view with a "normal" 50mm lens on a 35mm format camera.
DX format camera finders are rated at 50mm even though 35mm is closer to "normal" on the smaller format. So to get the effective magnification you have to divide the value by the crop factor.
So the corrected value of the D70 viewfinder would be .50x (rated at .75x at 50mm) and the D200 would be .63 as you calculated.
But I think few people are interested in using their cameras with stereo vision. I think most of us just want an image that fills the visual field like we're used to expecting with a good 35mm finder.
I figured we got tunnel finders because DSLRs started out being based on film bodies. On my Fuji S2, the finder is N80 all the way. The only thing changed is the size of the black frame that crops the image area. A mask is cheap, new eyepiece optics and display readouts are more expensive.
But I wonder if there's some inertia with designers who are steeped in the 50mm 1.0x "ideal" and that's why magnification isn't as high as the new smaller format could benefit from.
But there's also a "geezer" factor at work here. The viewfinder magnifications have been getting smaller than the 1x "ideal" so that folks wearing glasses can take in the whole image with the related display areas. The so-called "high eyepoint" magnification (or lack thereof). Perhaps DSLR designers are trying to factor in all the boomer eyeballs needing glasses...