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Canon AE-1P, Flash sync speed with pc cord

Brian Louie , Apr 04, 2007; 09:00 a.m.

I'm trying to practice photography with a vivitar 3500 for the first time. I have a dedicated module which I believe syncs to 1/60 at the max. If I use a module that uses the pc sync cord, is 1/60 still the max that the camera will sync to the flash? Thanks.


Jack Fisher , Apr 04, 2007; 09:16 a.m.

Yes. It is the same.

Mike Santos , Apr 04, 2007; 11:49 a.m.

It does not matter what brand or model of electronic flash you use or whether you use the hot shoe or a synch cord. ALL A-series cameras have X-synch at 1/60 second. X-synch is a function of the shutter curtain speed and the A-series cameras used a horizontal cloth focal plane shutter and like 99.99% of this type of shutter in existence they synch out a a max speed of 1/60. Note: If you have a dedicated flash (with the three little contacts) the flash will set the camera to 1/60 NO MATTER WHAT you have the shutter set to. If you want a Slower speed you're SOL, unless you use a non-dedicated flash (only the one contact pin) or if you have an A-1 and CERTAIN flash units, namely Canon SpeedLight 199A, 299T, 533G, or 577G. These units allow an A-1 (only) to set anywhere from 1/60th sec all the way down to 30 seconds.

Mark Wahlster , Apr 04, 2007; 02:04 p.m.

Excellent answer Mike. To add the Canons with faster sync speeds.

EF 1/125 (due to it's vertical travel Copal Square Shutter)Only body with a fast sync and MLU (mirror lock up)

T-70 1/90th (Hot shoe only no PC socket)

T-80 1/90th (Hot shoe only no PC socket)

T-90 up to 1/250th also the only FD body with TTL flash when used with the 300TL speedlite or ML-2 Macro ring light. (Hot shoe only no PC socket)

F-1N 1/90th

Think I got them all.

Brian Louie , Apr 05, 2007; 08:39 a.m.

Thanks for the answers everyone. Very helpful.

Jeff Adler , Apr 05, 2007; 09:48 a.m.


I have many cameras with Copal Square shutters, including an EF. Although these cameras are marked at 1/125 for flash synch I have been told by several repair people that they actually fire at 1/100 when attached to a flash (hot shoe or pc cord).

Jeffrey E , Apr 05, 2007; 10:22 a.m.

You can however use a slower shutter speed by using a PC synch cord, or by covering up two of the contacts with tape. If you use the flash off camera by using the synch cord the flash no longer overrides the shutter control and so a slower shutter speed is available. But for the reasons above, a faster shutter speed than 1/60 is not available.

Mike Santos , Apr 14, 2007; 12:59 a.m.

Excellent point. With a PC cord, the flash cannot set the camera's shutter. Bear in mind that to use a Canon Speedlight A (155A, 177A, 199A) or G series (both) or T series (299T and 300 TL??) you need Canons proprietary Synchro Cord A, because the the Speedlights have a weird two pin connector a circle and a slot that the Synchro Cord A plugs in to. The other end is a regular PC cynch contact.

How do these old copal shuttered cameras know if a flash is attached? The Canon EF made use of a switch, but a few of the others that I've seen - and it's been a loong time - I don't recall them having any way of kowing that a flash was attached. If there's a separate X synch setting I can nderstand that.

Also in addition to the A-1, the F-1N (I like to call it New F-1) and the T90 are also capable of slow synch photography with 199A, 533G, 577G and 299T (the 300TL can do even more on the T90, like 2nd curtain synch). The second curtain synch really intrigued me - still does, maybe one of these days.... I would have to sell one of my Montreal F-1s first!

Some of my Olympic F-1s

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