Shutter sync. dial, Acme #4. : LUSENET : Large format photography : One Thread

I have a LF lens I am setting up for portraiture with a Calumet 4x5 monorail. The 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 shutter, and a manual cocking flash synchronization control. All is well except understanding the flash sync dial with 4 settings. The dial has a number range and 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 exactly stated) All four settings consistently fire a strobe from the 2 prong contacts. My question is how do I use/interpret this dial next to the sync contatcts? Are the settings delay after shutter full open?

-- Robert Paluf (, October 13, 2000


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

-- David Goldfarb (, October 13, 2000.

My guess are that the numbers indicate milliseconds of delay from flash firing to shutter opening. 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.

-- John H. Henderson (, October 13, 2000.

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