Godfrey, interesting study. Wished there was a DA 28/2.8 AL. Henk
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Godfrey DiGiorgi Sent: 24 January, 2007 10:35 PM To: PDML List; SeePhoto Talk Subject: Pentax FA28/2.8 AL vs FA35/2 AL lenses: how do they compare? Since I bought the FA28/2.8 AL very recently and have been shooting with the FA35/2 AL for over a year, I've been very interested in how their performance compares. To test them, I've carried both with me for the past three day's walking around the neighborhood with the K10D and taken a range of photos of same and similar subject matter with both, using Av and testing in sequence f/2.8, f/4, f/5.6, f/8, f/ 11 lens openings. I sorted all the exposures by lens opening after doing quick and basic white balance and exposure adjustments with Camera Raw to render them approximately even in exposure value on common target points. No sharpening of any kind or any adjustment to contrast was performed, they're all set at the defaults on those parameters. The exposures were then output to full resolution, minimum compression JPEGs for comparison. Results are pretty simple: - Rendering qualities of both lenses are virtually identical and very pleasing, with the FA28 having a slight edge between f/2.8 and f/5.6. - Sharpness at f/2.8 is better on the FA35 (indeed, sharpness at f/2 with the FA35 beats the FA28 wide open). Contrast on the FA28 is also slightly lower at f/2.8. - Sharpness and contrast come up very fast on the FA28 ... by f/4, they are extremely close to the FA35, and by f/5.6 the two lenses are virtually indistinguisable from one another. The softness of the FA28 wide open make it less suitable for very low light work with hard edged subject matter, but its f/2.8 maximum aperture puts it at a disadvantage to the FA35 for that kind of work anyway. The slight improvement in rendering qualities nets a slightly more pleasing photo in some instances at f/2.8 and f/4 when ultimate detailing is not as significant. For low light work, the FA35/2 is the obvious choice and the FA28/2.8 works out better in more average lighting situations. However, the primary reason for wanting the FA28 has nothing to do with ultimate sharpness wide open, it has more to do with field of view dynamics ... you can't substitute a DA40 or FA35 without giving up the FoV characteristics. Since most of my street photography is done at f/5.6 to f/11, and focused by zone rather than with AF or manual focusing through the lens, the FA28 is a very useful lens for my needs. BTW, I also compared it to the Pentax-A 28/2.8 exposures I'd made way back when I first got the *ist DS. The FA28/2.8 AL performs SIGNIFICANTLY better than the pristine A28/2.8 wide open and I see no sacrifice of the latter lens' superb OOF rendering qualities. By f/ 5.6, the A28/2.8 is almost on par, but the FA28 continues to have better sharpness and contrast all the way through the aperture range. BTW: in the course of testing with these two lenses, I also was playing with the Program exposure mode on the K10D, trying to see differences between the "Normal" and "MTF" program lines. With the FA28, the MTF program line favors f/4 to f/5.6 through the majority of the range, where the normal program line tends to run it between f/ 5.6 and f/8. I *still* want a Pentax-DA 28mm f/2 Limited lens. ;-) Godfrey -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
