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Pfiltz
11-Aug-2013, 10:36
Sorry for the newb question. Been a year or so, since I used any type of flash with my 4x5.

There's a sync switch on the lens, labeled M, M, F-X, OFF

Which one should I use to get flash sync? If figure OFF is self explanatory... ;)

MODS, please move this to the LENS forum. Sorry.

Otto Seaman
11-Aug-2013, 10:47
~X~

Pfiltz
11-Aug-2013, 10:51
TY Otto...

Leigh
11-Aug-2013, 12:51
There's a sync switch on the lens, labeled M, M, F-X, OFF
M is for medium-duration flashbulbs. This was the most common type.

X is for electronic strobes.

I presume F-X is a compromise that works with fast-duration flasbulbs and strobes. I've never seen that before.

I don't understand why you have M listed twice.

- Leigh

Bob Salomon
11-Aug-2013, 14:02
M is medium peak flash bulbs, x is for electronic flash, F were for gas filled flash bulbs.

Jim Jones
11-Aug-2013, 18:36
It's always a good idea to check the actual sync with an electronic flash, regardless of the shutter vintage or markings. As electronic flash replaced flashbulbs, the timing in many older shutters was internally modified from F or M to X with no external indication of this. The modification could be quite simple.

AtlantaTerry
13-Aug-2013, 22:57
Set your strobe to a low power.
Set the shutter's synch to "X".
Open the lens to the maximum aperture.
Set the shutter speed to the fastest setting.
Hold up the lens about an arm's length away.
Aim the lens toward the strobe.
Trip the shutter.

You should see a circle of light.
If you see a star then the synch is off because the shutter is either opening or closing when the flash went off.

You should perform this test at least once a year with every shutter. (I do it between Christmas and New Year's Day when there is nothing much else going on.)

Leigh
13-Aug-2013, 23:47
Aim the lens toward the strobe.
Could cause severe eye damage, depending on the strobe power.

Point the strobe at a light-colored wall from several feet away, and point the lens at the same spot.

- Leigh

AtlantaTerry
14-Aug-2013, 00:59
Leigh,

Yes. That is why I said to set the strobe to a low power.

pasiasty
14-Aug-2013, 03:55
And check the bloody switch before each shot, on some shutters it tends to change while you manipulate with time, cocking lever or so. And you won't see anything wrong unless you develop clear sheets.

Bob Salomon
14-Aug-2013, 06:50
Set your strobe to a low power.
Set the shutter's synch to "X".
Open the lens to the maximum aperture.
Set the shutter speed to the fastest setting.
Hold up the lens about an arm's length away.
Aim the lens toward the strobe.
Trip the shutter.

You should see a circle of light.
If you see a star then the synch is off because the shutter is either opening or closing when the flash went off.

You should perform this test at least once a year with every shutter. (I do it between Christmas and New Year's Day when there is nothing much else going on.)

It is safer to point the flash and the lens towards a light colored wall rather then point the flash towards the lens.
The results will be exactly the same.

Otto Seaman
14-Aug-2013, 07:48
I wonder if he ever shot yet?

Jac@stafford.net
14-Aug-2013, 08:57
I don't understand why you have M listed twice.

There are probably two 'M' markings. Both are for medium bulbs.
The red M is to match shutter speeds that are also colored red.
F-X is for the little, fast bulbs and electronic flash.

Leigh
14-Aug-2013, 09:07
Leigh,
Yes. That is why I said to set the strobe to a low power.
Without specifying a particular strobe model and power level, "low" has no meaning.

The lowest position on many of mine is 250 watt/seconds.
That will definitely hurt your eyes if you look straight into it.

Is there something wrong with trying to protect folks from injury?
That was the purpose of my post.

- Leigh

Leigh
14-Aug-2013, 09:09
There are probably two 'M' markings. Both are for medium bulbs.
The red M is to match shutter speeds that are also colored red.
Ah. That makes sense.

Thank you.

- Leigh

Pfiltz
23-Sep-2013, 07:19
Hello all.

I'm sorry I never got back to my thread. I didn't take any shots with the strobes, as that chance came and went without me shooting. The reason I asked about the two M's was because I have two on the lens, that you all have addressed.

Thanks again.