Acme Synchro Shutter flash sync question

[ericantonio]

Okay nerds, I got a good one. On the side of the old Acme is a lever for the flash sync. I KNOW for sure my flash is working and I tested the same f/stop shutter combo on my digital camera. On the side it says M BLU, F WH, X RED.
I thought many years ago I've used this lens with a flash and it kinda worked. I think I used it with flash outdoors as a little fill.

I kinda remember that one of the settings is for old school flash bulbs aka, WEEGEE style, and it doesn't go off immediately. So if I were to use the Acme Shutter with bi-post (yes, I have bi-post cable to a flash trigger), it needs to be on the X RED settings right?


I thought it didn't matter because all our LF shutters sync at all speeds. Am I wrong? I think it was set on the Blue (M) and for the life of me, I processed film and they were blank thinking it didn't sync.

[Mark Sampson]

'X' synch is for electronic flash, which fires instantaneously when the shutter is triggered.
'M' synch is for regular flashbulbs. There is a several millisecond delay for the flashbulb to ignite. So on 'M' synch your electronic flash fires before the shutter opens, yielding no exposure to the film. We've all done that at least once.
'FP' is for flashbulbs designed to synch with the focal-plane shutter- those have a very long flash duration to compensate for the time it takes for the FP shutter slit to travel across the film. A particularly blinding light, I would imagine, as it lasts a relatively long time. Such bulbs are rare now, I've never seen or used them.

[ericantonio]

Thanks Mark! I did more testing. At first I thought I had 1. bad developer, 2: shutter too high, so I had to make sure I did a few and make sure #1 was not a culprit.

Here's what happened, mind you this is 6 sheets.
Blue with 1/100 or maybe it was 1/150, the "M" no image or very slight. I tried this a few times and different developers thinking there was something wrong with my developer or the times (testing out d23 at same time, not a good idea to do tests with multiple things can go wrong)

X with strobes, my last test, the strobes did not fire. Hmmm, broken shutter? Maybe the dial is a little off"

Here's what worked:
M (blue dot), with 1/50th shutter worked. Finally, got it working but with 1/25th of a second shuttter. So I'm thinking my 1/100 was too tast. I'm going to play around the dial to see if the X is broken or just need to get it dialed into position just right. [EDIT], The strobe worked somewhere in between the white (FP) and red (x) dial.

I will try another one with F, white dot and about same shutter speed 1/25 or try 1/50th.

Thanks again! This was super helpful.

[ericantonio]

I'm guessing the White (F) is about 5milliseconds and Blue is 25mm which won't sync with 1/100 or even 1/150 (on Acme shutters). I'm thinking either settings blue or white, it will work with 1/50 and below? Or play it safe at 1/25?

[Tin Can]

I shoot all my flash BULBS at 1/30 or lower

Do some actual Flash bulb testing

Many bulbs have the same burn time and output

Test inside

Yes there are bigger more powerful, but unnecessary

Turbo by TIN CAN COLLEGE, on Flickr



Here is one blue bulb at 1/25

In a dark bar handheld

I see no movement, there were not dancing



.

[ericantonio]

What sucks now is that I won't be able to use this Acme outdoors with a fill. Bummer Man, I haven't used bulbs since I was 12 and using a 110 camera

[ericantonio]

Seems to work okay, haven't used these strobes in a while. Now to find a project.
Just got to remember. 1/50 or was it 1/25? And blue dot on lens. I have a bi-post to male and a female to jack Macguver cables with a trigger.