I would like to add that all designs are trade offs. To get one thing, you have to give up something else. Pentax mostly has, since I've been using them (1961), balanced things to the best look in the final print. Unfortunately, many manufactures seem to balance things for the best magazine test reports (good marketing). In many cases this is subtle in others it is obvious. I sometimes think Pentax developed Super Multi Coating (And SMC is still the very best coating system out there) because balancing things for smoothness tended to trade off contrast, SMC restores much of that lost contrast. In test reports Pentax glass often does not look that good. Yet most serious photographers who use Pentax when asked why will reply, "It's the glass".
The thing that made me comment in this thread originally was someone else's comment that the ist-D seems to be setup for best print quality, not best computer screen image. As I said, that does not surprise me.
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William Robb wrote:
----- Original Message ----- From: <[EMAIL PROTECTED]>
I am just curious how you (and Graywolf and whoever) would describe the Pentax "look." How you would describe its "picture quality" as, say,
contrasted to
Canon's. (Film and/or digital.)
Lens design is fraught with compromise. There is no such thing as the perfect lens. There are, I believe, six major distortions, some of which can only be corrected at the expense of others. So, you may be able to design a perfectly rectilinear lens, but you may also get uncorectable chromatic aberation, as an example. Lens designers, therefore, have to make decisions about what to correct, and what to compromise, and then to try to make an entire family of lenses with the same look. Some company's design philosophy is to have the highest resolution possible, others for the highest contrast, but this sort of philosphy tends to forsake other criteria. Others try to strike a balance between as many aberations as possible. When I was making the decision about which lens system I wanted to use, I tried Nikon and Olympus, and had close access to Canon, Leica, Pentax and Contax.
Leica and Contax were out of my price range. This, unfortunately, is too often the first compromise made.
Olympus had nice lenses. Really nice lenses. The camera bodies were small and fiddly though.
I never really fell in love with the Nikon lenses that I used. I had a very nice 50mm f/1.4 Nikkor which I thought was excellent. A 28mm f/3.5 that was decidely humdrum. A 24mm with visible barrel distortion and quite a bit of darkening in the corners, and a 200mm f/4 that was like the 28mm. it was there, but I could never find anything kinder to say about it.
In fact, of the pictures that I saw, I liked the ones from Pentax the best. The images have a nice balance, not so contrasty as to be garish, but not blah either. Mostly not razor sharp (though the exceptions are wonderful) but still very, very sharp. Good to excellent flare control, which is not all because of the SMC, some optical designs are more flare prone than others. Good control of barrel/ pincushion distortion, but not so as to impart over much chromatic aberation, and vice versa. I recall either reading or being told by a mentor that the two were inter related. I do think the Pentax lenses are more prone to coma, but I don't find that as irritating as other problems, and it may contribute to the nice boke that Pentax glass often has.
Anyway, you are right, it is very subjective, but for myself, of the lens systems I could afford, I liked Pentax the best. For me, it was a decision based on looking at pictures, not charts or spec sheets.
William Robb
-- graywolf http://graywolfphoto.com
"You might as well accept people as they are, you are not going to be able to change them anyway."
