Flash Sync Speeds on early Canon RF's?

Kirks518 · Sep 18, 2016

I have a Canon IIb (or at least I'm 99.99% sure it's a IIb), and it has a PC socket. From what I can find, this was added later (not factory original). It works just fine, but I'm curious about the shutter sync speed. I can find no info out there, and was hoping someone here may know. My gut says 1/60, but then I think maybe 1/30th.

Anyone know?

darkroommike · Sep 18, 2016

It might even be 1/15th! My Canon L-1 syncs at 1/45 (at least it's between 1/30 and 1/60). Shoot a test at each speed.

ransel · Sep 19, 2016

I wonder if you could take the lens off, point the camera at a a white wall or sheet of white paper, flash connected and on, and with the camera back open observe the camera back (what's the area called where the film get's exposed when the shutter opens?) trip the shutter while looking at the open camera back and see what shutter speed is completely open when the flash goes off. That should give you a visual of the correct max sync speed for flash photography. My Canon P doesn't give any indication of sync speed either.

Kirks518 · Sep 19, 2016

Ransel, I think it's called the 'film gate'.

The Canon IIb is a Barnack design, it loads film from the bottom, so that idea, while a good one, wont work with this camera.

I'm going to shoot a test roll and see where it falls. I'll post the result when I do it.

AgX · Sep 19, 2016

Kirks518 said:
The Canon IIb is a Barnack design, it loads film from the bottom, so that idea, while a good one, wont work with this camera.

In the past a german flash manufacturer just for this test with Leica-like cameras offered a phosporescent foil to insert in the camera.

wiltw · Sep 19, 2016

Do not forget that there could be MULTIPLE flash sync speeds...one for 'electronic flash' (X), one for 'flash bulb' used with leaf shutters (M), one for 'flash bulb' used with focal plane shutters (FP)

Kirks518 · Sep 19, 2016

wiltw said:
Do not forget that there could be MULTIPLE flash sync speeds...one for 'electronic flash' (X), one for 'flash bulb' used with leaf shutters (M), one for 'flash bulb' used with focal plane shutters (FP)

That's possible/probable due to the vintage, but from what I've been able to determine, PC sockets were not put on at the factory, and I would 'guess' that the installed socket was put on with a specific type of flash in mind. My hope is that it is an X-sync, because I think I can run into difficulties with an electronic flash if it was an M-sync (doubtful as the shutter is FP, not leaf), or for regular bulbs. If I'm correct, I think if it's for bulbs, the firing happens at 1st shutter opening (giving the bulb enough time to get to full output power), which would render it pretty useless with electronic flash (which fires at 1st shutter full open if what I know is correct).

jimjm · Sep 19, 2016

The IIB was made from '49 to '51, and Canon did not introduce built-in flash synchronization until 1950 with the Canon "1950" (very rare) and the Canon IV. I have a IVSB with an X-sync at 1/15 with peak-type bulbs or electronic flash. Using older focal-plane type bulbs with longer duration, it'll sync from 1/25 to 1/1000.

The older IVS has an X-sync of 1/8 sec, so I would guess your IIB would be the same, or maybe 1/4 sec as it's an older design and I believe the shutter is of the same design as the S-II from 1946.

jimjm · Sep 19, 2016

Kirks518 said:
That's possible/probable due to the vintage, but from what I've been able to determine, PC sockets were not put on at the factory, and I would 'guess' that the installed socket was put on with a specific type of flash in mind. My hope is that it is an X-sync, because I think I can run into difficulties with an electronic flash if it was an M-sync (doubtful as the shutter is FP, not leaf), or for regular bulbs. If I'm correct, I think if it's for bulbs, the firing happens at 1st shutter opening (giving the bulb enough time to get to full output power), which would render it pretty useless with electronic flash (which fires at 1st shutter full open if what I know is correct).

Canon's flash synch was via side-mounted rail on the body. Any other type of PC sockets or connectors would have been added post-factory. I've seen photos of the IIB with a synch socket added on, just under the slow speed dial, so it may not have been that uncommon.

John Koehrer · Sep 19, 2016

Agx's method is what I used. Glow in the dark tape on a piece of thin card inserted behind the gate.

You can do it from the front by putting an index card at the gate and aiming the flash into the lens mount and watch it that way.
You're only looking for side to side exposure so having a shadow on the long edge doesn't really matter.
Keep in mind you don't have to have your head or the flash all that close to the camera. Think I'm takin' a selfie.

wiltw · Sep 19, 2016

Kirks518 said:
That's possible/probable due to the vintage, but from what I've been able to determine, PC sockets were not put on at the factory, and I would 'guess' that the installed socket was put on with a specific type of flash in mind. My hope is that it is an X-sync, because I think I can run into difficulties with an electronic flash if it was an M-sync (doubtful as the shutter is FP, not leaf), or for regular bulbs. If I'm correct, I think if it's for bulbs, the firing happens at 1st shutter opening (giving the bulb enough time to get to full output power), which would render it pretty useless with electronic flash (which fires at 1st shutter full open if what I know is correct).

I found user manual for the Canon IID

'High speed sync' is for Focal Plane bulbs at 1/35
'Speedlight sync' is for electronic flash at 1/25 on the high speed control and the slow speed control on 'X'
'Slow speed sync' is for a different type of bulb with the slow speed control on 1/25

Kirks518 · Sep 19, 2016

Here's a pic of the camera's PC socket. From what I can determine from pics of other IIb's, they removed a screw, and put the socket where the screw was.

Kirks518 · Sep 19, 2016

wiltw said:
I found user manual for the Canon IID

'High speed sync' is for Focal Plane bulbs at 1/35

'Speedlight sync' is for electronic flash at 1/25 on the high speed control and the slow speed control on 'X'

'Slow speed sync' is for a different type of bulb with the slow speed control on 1/25

As you can see, my camera doesn't have any of those speeds....

Where did you find the manual, Butkus?

wiltw · Sep 20, 2016

Kirks518 said:
As you can see, my camera doesn't have any of those speeds....

Where did you find the manual, Butkus?

Just found the IIB manual, also on Butkus...the same three modes and settings apply.
But the manual does not state IIB specifically, and it does state that the IID is NOT synchronized!

Kirks518 · Sep 20, 2016

Maybe I'm blind, but the manual I find on Butkus for the IIb says nothing about sync speeds. The word sync isn't anywhere in the manual.

wiltw · Sep 20, 2016

Canon IIB links to this web address on the Butkus site
http://www.butkus.org/chinon/canon/canon_rangefinders_lenses/canon_rangefinders_lenses.htm

pages 27-30 speak to flash sync.
The manual on page 27 mentions specifically IV-S2 and II-S, so Butkus has it linked incorrectly.

Kirks518 · Sep 20, 2016

I see what you guys are saying in the manual that covers the IId, S2, and IV, but it doesn't have the IIb (except in the model history at the end).

RalphLambrecht · Sep 20, 2016

Kirks518 said:
I have a Canon IIb (or at least I'm 99.99% sure it's a IIb), and it has a PC socket. From what I can find, this was added later (not factory original). It works just fine, but I'm curious about the shutter sync speed. I can find no info out there, and was hoping someone here may know. My gut says 1/60, but then I think maybe 1/30th.

Anyone know?

I do not know for sure,but think it's safety assume 1/60s

jimjm · Sep 20, 2016

IIB was before Canon introduced flash synch, so no mention in the manual. Canon was a bit confusing with the naming and features of their bodies (the IIC was introduced after the IIB), so one can't assume a higher model name was made later, or has more advanced features. The factory sometimes did install flash synch on the IIB, but with a side-mounted rail, not a synch socket like yours.

My IVSB is a few years later than yours and is X-synced at 1/15, so I would try some test shots using 1/15, 1/8 and 1/4. Kinda hard to tell beforehand since it's a post-factory conversion.

Jim Jones · Sep 20, 2016

Kirk - Since the high shutter speeds start at 1/20 second according to your shutter speed dial, that is the highest speed that can expose the entire 24x36mm frame by electronic flash, assuming the flash is triggered just as the opening shutter curtain clears the film gate. A FP flash bulb can be used at any shutter speed with about a 20ms delay , although much light will be wasted at the higher shutter speeds.

Kirks518 · Sep 20, 2016

Thanks Jim. So 1/20 should be my sync speed. Wow.

Flash Sync Speeds on early Canon RF's?

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