There was a recent discussion here about the DA* 55/1.4 and a question raised about how it might compare with the other Pentax 55mm lens, an early PK 55/1.8. And I had nothing better to do except grade papers and assign final grades for the semester, so I did some comparisons.
The contenders - a. PK 55/1.8 b. DA* 55/1.4 c. DA* 16-50/2.8 @ 50mm d. DA* 50-135/2.8 @ 55mm And I couldn't find my PK-A 50/2.8 macro or PK-A 50/1.4 (they must still be in KC) but I did come across and include e. FA PZ 28-105/4-5.6 @ 55mm And while I was in the "testing" mode, I also looked at - q. DA* 50-135/2.8 @ 135mm r. PK 135/2.5 s. PK-M 135/3.5 The set-up: K20D, on a tripod, looking out through my home-office window. Manual focus on some berries to the left-center of the frame, 20+ meters away. Focus assist from LiveView @ 8x. (I didn't use the viewfinder at all.) Manual selection of aperture, match-needle exposure setting. Shutter tripped via remote with 3 sec. delay I did a simple series with each lens, including f/1.8 (or whatever the widest aperture was if it didn't go down to 1.8), f/4.0, and f/8.0 The DNG files were brought into LR3.3, then exported as reasonably high quality JPEGs with no post-processing other than some minor exposure tweeks. NOTE: a big problem here is with the focusing. Do NOT take these results as any indication of the absolute performance of these lenses. My eyes are just not good enough to guarantee that I achieved the same focus-point with all lenses. And then there is the factor of the window I was shooting through. It is fairly clean, no direct light shining on it inside or out, but still ideally I should have been outside freezing my fingers off. Maybe another time. In addition, I did one test-chart shot, using one of the focus-test templates, with camera on a copy-stand. The following lenses were subjected to this process: a. PK 55/1.8 @ f/1.8 b. DA* 55/1.4 @ f/1.8 c. DA* 16-50/2.8 @ 50/2.8 e. FA PZ 28-105/4-5.6 @ 55/4.5 The images may be found here: http://photos.stanhalpin.com/p566717840 If that doesn't work for you, go to http://photos.stanhalpin.com, then navigate via the PDML-GESO folder to the Lens Test sub-folder. You'll see thumbnails; once you click on a thumbnail, a larger image will come up with it's caption underneath describing which lens at what aperture took the shot. Enjoy! stan -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
