I have examples of my DA* lens giving me sub-par real-world results. Here's the "real world" image:
http://www.westerickson.net/misc/ValleyOak.jpg Here are 100% crops of the left, center, and right portions of the image. Note that some of the grassland on the both the left and right sides is in the plane of focus. http://www.westerickson.net/misc/LeftCenterRight.jpg The blurring on the right side is noticeable in an 8x10 print that I made with my Epson R800 printer. The problems are obvious in this test image: http://www.westerickson.net/misc/ProblemDAStar1650.jpg Note that I used exactly the same setup (camera in same position) with my FA 50mm F1.7 as a control, so I know that the wall and camera are aligned. My local authorized Pentax service center evaluated the lens, noted the defect, and sent it back to Colorado per their instructions.... --Mark Paul wrote: >I decided to continue my upgrade of the medium zooms with the >addition of the DA* 16-50/2.8. It's an ideal lens for event >photography, which I've been doing more often. My lens arrived >Monday. I tried to adjust the focal point yesterday using the Nikon >chart. I had a lot of problems getting a compromise reading at the >various focal lengths. More disturbing was the fact that the left >side of the chart and the right side of the chart weren't focusing on >the same plane. I conferred off list with Joe Tainter, who is well >informed on these problems and decided to test further. Today I >tested the lens by shooting a flat wooden deck off the tripod. The >level of the deck and the camera were checked and matched with a >bubble gauge. The lens is definitely our of whack by a considerable >amount. It's easily noticeable in this sort of test at 2.8 and all >focal lengths and still somewhat noticeable at 50mm, f5.6. It's on >its way back to B&H and a replacement is on its way to me. In normal >shooting early yesterday the problem wasn't noticeable. (I have a >nice pic of Grace playing hopscotch:-). Anyone who has purchased this >lens should test their sample under controlled conditions. -- 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.
