most modern telephotos really are better than most extreme wide angle lenses. Below 28mm focal lenght almost all lenses for 35mm SLR cameras suffer from severe fall-off of resolution and contrast from the image centre to the image border. If you look at the MTF diagrams given e.g. in ColorFoto, you can easily check this. Also, I myself have tested the famous K15/f3.5 and FA24/f2 lenses, and I came to the same result: Good in the image centre but problematic at the borders....
Arnold
[EMAIL PROTECTED] schrieb:
Hi,
I wonder how these tests are useful for us from the magazine. Nearly all 24mm lenses got less than 70 points out of 100. It seems that tele lenses get much higher notes than wide ones.
Strange. SO maybe you are they are tested nearly full open.
What do you think?
And in this magazine Fa100/2.8 macro got very high mark - 86
Well done Pentax
And in US magazine it was only 6/10.Also strange. Are there any huge optical differences between the same lenses or just diff conditions of tests?
Alek
Użytkownik Arnold Stark <[EMAIL PROTECTED]> napisał:
In the February edition of German ColorFoto (CF) magazine the SMC Pentax-FA 1:1.8 31mm Limited and the SMC Pentax-FA 1:2 35mm AL are tested along with 35mm/f1.4 lenses from Canon, Leica R, Minolta and Zeiss, 35mm/f2 lenses from Canon, Leica R, Minolta and Nikon, and a Zeiss 35mm/f2.8. For the last two years, the CF lens tests have shown a lot of consitency. Unfortunately CF usually tests lenses wide open and two stops down, so it is hard to compare the MTF results of lenses of different maximum aperture. However, this much can be said:
Of the lenses with f=1.8 or 2 maximum aperture, Minolta and the two Pentaxes offer the best image quality with 20 points (out of 30) for sharpness/resolution and 28 points (out of 30) for contrast. Canon is close (19 and 28 points) while Leica (18 and 27) and Nikkor (17 and 27) are defeated. Looking at the MTF curves, the Minolta 35/f2 offers the best performance wide open. However, at f=4 the MTF of the the Pentax 31/f1.8 is by far the best with unusually small fall-off from centre to corner. Light fall-off (vignetting) is relatively well controlled in all lenses (7 points out of 10) except for Leica (5/10). The Leica (6/10), Canon (6/10) and Minolta (7/10) 35/f2s offer slightly less distortion than Pentax (5/10 each) and Nikon (5/10). The Minolta offers excellent centration (? Zentrierung in German) with 20 points out of 20, while Leica (18), Nikon (17), Pentax 31/f1.8 (17), Pentax 35/f2 (16), and Canon (15) offer good to mediocre centration (of the lens elements) only.
BTW: Of the lenses with f1.4 maximum aperture, Canon and Leica are the best, however, at f2.8 the Contax 2.8/35 beats them all.....
Arnold
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