----- Original Message ----- From: "J. C. O'Connell" < Subject: RE: Kinda OT: MF Enabled
> I have to disagree with respect to sharpness. Many of the old TLR > do not really have outstanding sharpness. The old single coated > lenses ( Non SMC) tends to reduce apparent sharpness IMHO. > Also flare can be a problem with certain lighting conditions. > Most of the TLR have 4 element lens designs at best too. > Another major factor with medium format is the shallower DOF > gives a smaller zone of critical focus, I find this to be > a disadvantge in many cases vs. 35mm. The thing is, they don't have to be outstandingly sharp to beat out even a very good 35mm lens. They only have to be fairly sharp. A very good camera lens (something like a Pentax LTD) will resolve perhaps 60 lppm under normal shooting conditions (6:1 toc). An MF system only needs to resolve around 36 lppm to get equivalent detail to the film. I would dare say that any of the quality TLR cameras made since the erea of lens coating began will give a more pleasing final image than any 35mm system on the market today. There is no such thing as apparent sharpness. Sharpness is an absolute and quantifiable value. There is nothing wrong with simple lens designs, especially if the optics are uncoated, or single coated. The fewer air/glass surfaces the better in any lens. Some of the sharpest lenses made are 4 and 5 element designs. The Apo Artars are legendary for sharpness, yet are a 4 element Tessar type from 50 years ago. Remember, multi coating does not eliminate flare, it just mitigates it to a manageable level. A photographer does need to be more aware of potential flare situations with an uncoated lens, but a good lens hood will cure most flare. I have found through many years of exposing film that if there is a lot of flare potential, I probably have the camera pointed the wrong direction anyway. I prefer to have the light source safely behind me when taking pictures. For some reason, they just seem to turn out better that way. I have never found that there is an advantage with 35mm regarding critical focus. In fact, just the opposite. The larger view screen, and the ability to put a loupe right on the screen is an inherent advantage that MF and LF has over 35mm cameras, with a few exceptions, such as the LX. What works against 35mm is the small negative size. To get a good enlargable negative from 35mm, everything has to be just right. The exposure has to be exactly correct, the focus has to be exactly right, and the lens has to be at the best aperture. This can get in the way of the creative process. For example, you want a specific amount of DOF in the image, but your lens isn't sharp enough at that aperture. So, do you compromise the sharpness of the subject to get the DOF, or the DOF to get the subject sharp enough? With MF and LF, many of these decisions are rendered moot because you are not magnifying the negative as much, and therefore, you have more freedom to make creative decisions without regard of any technical difficulties the lens may induce. Most experienced photographers and photo writers agree that it is far easier to make excellent pictures from MF. You have to work a bit harder in the field, but you don't have to work anywhere near as hard in the darkroom. I think Mike Johnston said something like that in a 37th frame column. Or maybe it was David Vestal, I don't remember. William Robb - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
