Hi Shel, To test the aperture mechanism, stop the lens all the way down, hold the aperture open with your finger via the lever on the back of the lens, wait a few minutes and then release the lever as fast as you can while looking thru then lens. The blades should close _way_ faster than your finger can move. Repeat several times and I'll bet you'll see variations. Putting it in the fridge for a while will probably make the variations more obvious. Remember, it's the fast closing part that counts, it has all the time in the world to open back up. You can always send it to "Don's house of lens repair" if you need to. ;-)
Don (I _don't_ do zooms!) ;-( > -----Original Message----- > From: Shel Belinkoff [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 20, 2005 7:02 AM > To: pentax-discuss@pdml.net > Subject: Re: Re: istDS Exposure Problems > > > I wanted to eliminate the aperture from the equation, Mike, and see if it > was something within the camera. After your comment I did the test again > with the aperture @ F8.0. Exposures were erratic. I guess the lens needs > a CLA :-(( > > Thanks to all for your suggestions. > > Shel > > > > [Original Message] > > From: mike wilson > > > Don't you need to do the same with the aperture at least > partially closed? > >
