After shooting a lot of pictures with short focal length lenses on the *ist D today, I partially changed my mind, so I can correct myself here below.
DJE wrote: > > 15/3.5 A > > 20/4.5 SMC Takumar > > 20/2.8 Zeiss Jena Flektogon > > 24/2.8 A > > 24/2 FA* > > 18-35 FAJ > > 24-90 FA > > 28-70/4 FA > > Unfortunately most of the primes on this list are older optical designs, > primarily because pentax hasn't made a lot of new ultrawides I assume. > The 15/3.5 design apparently isn't great (nor is the equivalent Nikkor), The 15/3.5 is great for angle coverage (interesting perspective) and excellent distortion correction (better than its competitors). Sharpness it's not its strongest point, even on film. > the 20/4.5 is generally held to be not the best. See: http://www.dariobonazza.com/t04p7e.htm > Kinda surprised that > the 24s don't perform better, but I've never tested a 24 (Pentax or Nikon) > that performs as well as longer lenses. Yes, they perform better then shorter ones. See: http://www.dariobonazza.com/t04p8e.htm > Don't know anything about the > Flektogon, other than that I'd like to have one if I could find one. On film, I like the Flektogon very much. On the *ist D it shows some problems. However, I'm not sure focus was perfect. > The zooms don't surprise me as mediocre performers at wide angles, as > zooms are always compromises and making a good one is more expensive than > pentax normally markets. (This is not to say that Pentax zooms are bad, > just that they aren't as good as the $1750 zooms from C and N) All this makes sense. However, I'm surprised that Pentax glass should have so much problems on a DLSR, while most C/N lenses seem to comply rather good with their respective DLSR's (even mid-price zooms). > I'm curious what is WRONG with the images delivered by these lenses on the > *istD, especially compared to the images delivered by the same lenses on > film? Sharpness and contrast? Actual resolution and sharpness. > (The *istD is known to "undersharpen" its > images electronically, I don't think this can be enough for explaining the difference. Add any sharpening in Photoshop and you still don't get resolution you've lost. > and the sensor in it does appear to be less sharp > by nature than the Canon and possibly the Fuji sensors). At long last, you told that! This cannot be overcome by any postprocessing means. > Distortion? > It's a real pity that you can't mount the same lenses on some other > digital and compare results to know if all the wides are bad or the camera > is bad. I agree that a final word when comparing digital cameras could only be told by using the same lens. However, I couldn't do that at time of my comparison test, so I assumed that a good performer (but not the best around) like the Sigma 15-30mm used on the S2 won't be so much better than any comparable lens used on the *ist D. Is there any good reason for thinking that any Pentax lens used on a DSLR body, including primes in the same focal length range, should be worse than an average Sigma zoom lens? > I have not found ultra-wides to be great performers on film, in any brand > and at any price range, when compared to standard lenses. I'd actually > expect Pentax lenses to perform better on a digital camera than most > because Pentax seems to optimize for center sharpness at the cost of > corner sharpness and digital of course doesn't use the corners. > > How does the *istD perform with a lens of known outstanding quality? > If it is fine there then the problem is the lenses, although I think > you'll find that nobody's ultra-wide glass is great. See my pages: http://www.dariobonazza.com/t04p7e.htm http://www.dariobonazza.com/t04p8e.htm http://www.dariobonazza.com/t04p9e.htm http://www.dariobonazza.com/t04p10e.htm Is there any lens of outstanding quality among them? Can we assume that a lens of outstanding quality will be so on a digital camera? I've been told that the Nikkor 20mm is an excellent lens on film, and a mediocre lens on DLSR. I'm not sure if it's true, but could be. The problem is not just a bad lens on a digital camera, but a possible whole range of bad lenses on a (damn, partially!) compatible camera. Could this be the case with the *ist D? The Sigma 15-30 (or any other good performer on a competitor camera) will tell. Is there any owner of such a lens out there? Dario
