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Richard K.
6-Nov-2010, 10:15
I looked at the shutters on the Packard site and am either partially confused or thoroughly not entirely sure about how they work. It SEEMS that one can get either B or T type timed (#5) or that plus instantaneous (1/125 s) exposure (#6) but not the usual Copal type speed variety? Nice that they go up to 8" indiameter - I guess one could machine adapters to fit most barrel lenses? What is the Syncro shutter?

Thanks for any help!

dsphotog
6-Nov-2010, 10:42
The "Synchro" is a trigger switch to fire electronic flash when the shutter opens.

Merg Ross
6-Nov-2010, 11:02
Richard, I believe that the instantaneous speed on the Packard is 1/25 second. These are really great shutters once you get the hang of them; especially so if you have a collection of barrel lenses!

Another option, if you can find one, is the Luc shutter, although smaller than the Packards. I used a Packard on my 8x10 Agfa/Ansco 8x10 with good results.

Jim Galli
6-Nov-2010, 11:23
Richard, a page here on my site (http://tonopahpictures.0catch.com/Article_About_Packard_Shutters.html) may answer some of your questions about Packard shutters. I do the bulk of my whatever-it-is with Packards.

Ernest Purdum
6-Nov-2010, 11:51
The speed of the Packard at "Instantaneous" depends on the shutter size, the bigger the slower, as well as condition factors.

cowanw
6-Nov-2010, 12:35
The speed of the Packard at "Instantaneous" depends on the shutter size, the bigger the slower, as well as condition factors.


Which brings up a question I asked before, but never got a responce on. And that is, with the shutters such as the Packard or more particularily, the sinar, used as a shutter only,no f stop management, how can the rated speed be the same for lenses of varying back lens diameter.
If you have a 4 inch Packard hole mounted behind the lens, as an example, and use varying lenses with it, say, for example a lens with a 4 inch rear diameter and a lens with a 2 inch rear diameter, can the same speed pass the same amount of light for both lenses.
Won't the larger lens be at wideopen shutter for a briefer period of time?
Won't the smaller lens be open functionally for a longer period of time than if a 2 inch shutter was used?
Regards
Bill

Paul Fitzgerald
7-Nov-2010, 14:35
"Won't the larger lens be at wideopen shutter for a briefer period of time?
Won't the smaller lens be open functionally for a longer period of time than if a 2 inch shutter was used?"

Yes and yes, BUT the timing difference should not equal 1/3 stop of exposure. In practice it's really not a bother.

Ernest Purdum
8-Nov-2010, 17:56
[QUOTE=cowanw;646407 Won't the smaller lens be open functionally for a longer period of time than if a 2 inch shutter was used?
Regards
Bill[/QUOTE]

That's very true and the same is true when you change aperture settings of an interlens shutter like a Copal. As Paul indicated, it's one of the several rather small inaccuracies we mostly just live with.