Originally posted by Pål Jensen I have no problem manual focusing the K-7 although I would have preferred a larger finder. An FF finder isn't that much larger. You are overstaing the problem.
Actually, I'm not. A FF viewfinder is
much larger. You are being lied to by the camera makers in order to conceal just how bad APS-C viewfinders really are. Camera websites fuel this with their own incorrect assertions regarding relative viewfinder size.
Basically, the camera makers knew when trying to sell APS-C as a product that the viewfinder was going to show up like a sore thumb in the spec sheets, so they engaged in a massive sleight of hand - they calculated "magnification" using the
same focal length lens they used for 35mm format cameras. "Magnification" refers to the size of an object as it appears in the camera's viewfinder relative to the size of the same object viewed with the naked eye. The magnification should be calculated using a "normal" lens for the format, which approximates the magnification of the naked eye. In APS-C cameras, however that would mean viewfinder magnification should be calculated using a 33mm lens. In order to make it sound as if they had worked some kind of "magic" with APS-C viewfinders (as in they didn't lose as much size as the format did), the camera makers agreed to a fictitious "magnification" specification which is
based on the same focal length lens used for 35mm format, which is effectively a
telephoto lens on an APS-C camera.
Adjusting the fictitious APS-C "magnification" specs for the "crop factor," you will see the truth of the viewfinder size differential. The K7, for example, supposedly has a "magnification" of 95%, but with a telephoto lens on it. Adjust this magnification figure for the "crop factor" (i.e., divide it by 1.5), and the real magnification is more like
61.33%. Now it looks a great deal less impressive, doesn't it?
APS-C sensors (Pentax variant) are about 42.25% of the size of FF sensors, and the viewfinders are less than half the size, as well, attempts to conceal it from photographers notwithstanding. The fiction you're fed on internet sites that apply the "crop factor" to the fictitious "magnification" factors to determine relative viewfinder size is basically an assumption that APS-C sensors are
two thirds the size of FF sensors, which is complete nonsense. It's the equivalent of comparing two FF viewfinders, and calculating the "magnification" for the cameras using a 50mm lens on the first and a 75mm lens on the second. Would you accept such a comparison? I don't think so.