My DA 21 F3.2 Limited arrived yesterday, so last evening I went out to test it against the FA 20 F2.8. I followed my usual protocol:
Subject was a mud-brick wall, with cracks and many small rocks. Tripod. Distance for the DA 21 was about 1 meter. For the FA 20 I brought the tripod closer by a few cm. All apertures tested from wide open through F16. All photos processed the same in PS. All comparisons done at Actual Pixels. My tests are for sharpness across the field. Obviously this test doesn't allow for evaluation of bokeh. Both lenses seem well corrected for distortion. My usual caveat: I conduct these tests for myself. I post them as a public service in case anyone else finds them useful. If you don't find the test useful, you are free to ignore it. Wide open (DA 21 @ F3.2, FA 20 @ F2.8): The FA 20 is very slightly sharper across the field. Emphasis on "slightly." F4: The FA 20 seems a bit sharper in the center. The lenses are about equal at the edges and in the corners. F5.6: The FA 20 seems a bit sharper in the center and in the corners. The lenses are about equal at the edges. F8: The DA 21 is just slightly better in the center and in the corners. The FA 20 seemed a bit better at the edges. F11: The DA 21 is a bit better in the center and at the edges. The FA 20 seems slightly sharper in the corners. F16: The DA 21 was slightly better across the field. The bottom line is that these two lenses are essentially equal in sharpness. The FA 20 has a slight edge from wide open through F5.6. From F8 through F16 the DA 21 has a slight edge. But you have to go to extreme enlargement to see these differences. At more moderate enlargement one would have a hard time telling these lenses apart. Joe -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
