Shutter sync. dial, Acme #4.

[Robert Paluf]

I have a LF lens I am setting up for portraiture with a Calumet 4x5 monorail. T he lens optics are ILEX, 216 mm (8.5"), max aperature is f 4.5, time from 1 sec to 1/150 sec, with B & T settings. The shutter is an ACME #4, manual cocking sh utter, and a manual cocking flash synchronization control. All is well except u nderstanding the flash sync dial with 4 settings. The dial has a number range a nd settings of 0,5,10,23 and a corresponding color dot of black, red, blue, and yellow respectively. (The lens is at home, I writing from work and may not be e xactly stated) All four settings consistently fire a strobe from the 2 prong co ntacts. My question is how do I use/interpret this dial next to the sync contatcts? Are the settings delay after shutter full open?

[David A. Goldfarb]

Set it at "0" for X-sync (strobe). The others are for flashbulbs.

[John H. Henderson]

My guess are that the numbers indicate milliseconds of delay from flash firing to shutter opening. Graflex.org says that typical delays to peak flash output of bulbs commonly used on Graflex cameras was 20 - 21 milliseconds.

As stated, you'll want to use 0.

Or do this common sync test....point the flash at a wall, open the aperture and release the shutter while looking through it at the wall. If you are in sync, you should see the flash through the shutter.