A True "Normal" Lens?
Good morning, Darin;
All of the Minolta "normal" lenses will do well for you. As far as the maximum lens aperture goes, yes, it is true that the f/1.7, f/1.8, and f/2.0 lenses generally will be sharper near their maximum aperture, but the f/1.4 and f/1.2 will be back in the running by the time you get to f/4.0 and f/5.6, then all of them are very nice out to f/16. The real advantage to the f/1.4 and f/1.2 versions is the brighter viewfinder screen in low light and the narrower depth of field, both of which really help in getting the focus correct. If you look at the performance of the f/1.2 lenses, they are not as sharp wide open, but that often is offset by the ability to get that focus correct, especially with eyes that have developed an excessive accumulation of years.
Then we come to the focal length. Most often, people will tell you that the 50mm lens focal length is "normal." Then there is the "method" of calculating the diagonal dimension of the film negative to "determine" the "normal" focal length. I do not agree. That method is flawed from the beginning, because there are various film formats where the height to width proportion is different. It will be close, but it is not accurate. For me, the 50mm focal length is slightly wide angle. If I put a 50mm lens on a Minolta, Nikon, or other camera, and look through the viewfinder, I note where things are at the edge of the viewfinder. If I move my head up a little and view the same scene with my own eye, the things that were at the edge in the viewfinder seem to move out a little wider. With the 55mm lens, this effect is much less noticeable. With a 58mm lens on the camera, when I raise my head slightly, everything stays in place; nothing moves. To me, that is true "normal perspective," and what a "normal" lens should do. It shows me the same perspective as I see with my own eyes. To me, the 58mm lens is the true normal lens, beginning with the AUTO ROKKOR-PF 1:1.4 f=58mm and going through to the MC ROKKOR-PG 1:1.2 f=58mm.
I still believe that when Nikon, Minolta, Topcon, and others, came out with their first large aperture "professional level" normal lens for their SLR cameras, there was a reason why the focal length of 58mm was chosen, and I still say that it is for the reason that it provides true perspective for a normal lens.
The main advantage in getting a later lens, the ROKKOR MC and MD variants, is in the lens coatings. The later lens coatings are better, but, as with any lens, even one from the 1930s, you really can make it more flare resistant and improve the contrast just by putting a good lens hood or lens shade on it.
PM me and for the cost of postage I'll send you a 50mm f/1.7.
