Press Focus Problem

[scambug]

I seem to have a problem with the Press-Focus function on my new Nikkor 90mm/F8. The Press-Focus switch opens the lens to the pre-set f-stop rather than wide op en as I expected. Is there something obvious I'm missing?

[Brian Yarvin]

Arthur:

If it's in a Copal shutter, this is the way it's supposed to work.

Brian

[scambug]

Yikes! That's my mistake. I thought the Press-Focus function opened the shutter wide, regardless of its setting, like the automatic function on my Graflex Super D.

[Ken Burns]

Arthur:

Actually, the Preview Lever on the shutter does open the shutter wide open. It is important to realize that the shutter and aperture diaphragm operate separately. When preparing to expose a neg, don't forget to set the aperture diaphragm and/or to close the shutter before pulling the darkslide and tripping the shutter. Either way, you will ruin a neg. Believe me, I know all about making those mistakes as do probably everyone else working in large format.