I believe the rkn zoom has an inherent design problem which causes the vignetting when wide open. Nothing that can be done about it apart from stopping down till it goes away.
On Sun, Mar 31, 2002 at 09:15:22PM -0800, James Adams wrote: > I have an RKN MC Auto Zoom 35-70mm f3.5-4.5, and apart from vignetting at > 35mm, it has produced some really sharp images at 45-70mm. It is probably my > lack of experience of lower-range zooms that's causing the problem. > James > - > This message is from the Pentax-Discuss Mail List. To unsubscribe, > go to http://www.pdml.net and follow the directions. Don't forget to > visit the Pentax Users' Gallery at http://pug.komkon.org . - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
