Press Focus Problem : LUSENET : Large format photography : One Thread

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 open as I expected. Is there something obvious I'm missing?

-- Arthur Gottschalk (, September 15, 2001



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


-- Brian Yarvin (, September 15, 2001.

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.

-- Arthur Gottschalk (, September 15, 2001.


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.

-- Ken Burns (, September 15, 2001.

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