After much observation, and some debate, my wife, who has very fast eyes and I have determined that scenario 2 is the correct one. Were it otherwise, there would be no high speed sync available, which is why the camera has the built in shutter. The 90mm leaf reopens after the focal plane shutter completes it's cycle, the 165mm leaf does not reopen. William Robb ----- Original Message ----- From: Bolo Subject: Leaf shutter operation on Pentax 67 165mm f/4.0 LS
> I was curious about something and wondering if someone with the Pentax > 67 165mm f/4.0 LS lens or its manual could answer a question I > have about the operation of that lens. I don't have the lens or > a manual for it to examine or try myself. > > When the camera's shutter release is triggered, the auto-aperture > coupling from the body steps down the aperture and also triggers the > shutter. I can see two behaviors for this particular leaf shutter, > and I was wondering which is correct: > > 1) The leaf shutter stays open and starts running it's timer. > When the time runs out, it closes the leaf shutter. In other words, > the first curtain of the focal plane shutter acts as an open-shutter > event, and the actuation of the leaf shutter after delta-t acts as > the close-shutter event. This would seem to reflect the "not quite > a leaf shutter" comment that has been made. > > 2) The shutter closes immediatetly so that when the focal plane > shutter opens, no light is admitted. Then the leaf shutter opens and > closes depending upon it's own delta-t timer again. This is the true > leaf-shutter mode. However it is more complex than the first scenario. > > If the manual has the answer, that would be great. Otherwise, I > suppose one could determine this by triggering the 165 LS manually > and observing if it > 1) closes from the open position after shutter time > or 2) closes, then opens and closes again after shutter time? > > Thanks for any info. > Bolo -- Josef T. Burger - 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 .
