help with ae-1 sync speed

[weasel_bar]

After reading the manual for the ae-1 and manuals for a couple of

speedlites, it seems that dedicated flashes FORCE the shutter speed

to be 1/60. Even if you select a SLOWER speed, it still will be 1/60.

However, I did see a table in the ae1 manual where it seemed to

indicate that electronic flash allows sync speeds of slower than 1/60.

1)Is this really true? Can't one choose to sync slower than 1/60? I

want to use the flash just as fill, but in low light. If I have to

use 1/60, then I am forced to open up the lens wider than I want to

get the proper ambient/flash light ratio. (I have poor vision and

cant focus well enough if dof is a mere 3 microns on my 135mm)

 

2)Someone told me that if i cover up the back 2 pins, the flash will

be prevented from communicating a sync speed to the body. THe

central pin will tell it when to fire, end of story. I'm afraid to

mess around with this, though, bec. my flash is a Vivitar 3700

thyristor, and I think it uses high voltages.

 

Any help is appreciated. Thanks.

Sadashiv

[lee_brand]

It's important to remember that a sync speed is an UPPER limit, in other words the highest shutter speed that will sync with the flash. Any speed lower than this will sync OK.

 

Some flashes can be switched for "slow sync" - the SL199 for example. I am not actually sure if the flash will force the AE1 up to 1/60th from a lower speed like 1/30th? I would have to have my camera here! But I am very sure that someone else here will know!

[weasel_bar]

Generally sync speed is maximum. But for some reason the A series seems to be screwy. Don't have the body with me right now, so can't check, but I seem to remember trying to set the shutter to 1sec to test, and it was MUCH faster than 1sec (so I assume 1/60). Unendurable frustration, trying to figure this out.

[richard_oleson]

As I recall, the dedicated flash units automatically set the shutter to 1/60 when the flash recharges, regardless of what you have set. In fact, in the AE1, I think this is just about the ONLY "benefit" you get by using a dedicated flash. To use a slower synch speed, the best/easiest way is to get a non-dedicated flash unit. Many of these are very inexpensive and many are better units than the canon speedlites anyway.

 

The hard way is to cover the dedicated signal pins and just leave the big center pin exposed. there is high voltage on the center contact but not on the ones you need to cover up.

 

:)=

[timothy_fitzgerald]

This may not be the answer you're looking for, but I'm pretty sure that the AE-1 is not capable of slow-sync even with a flash that can set this option. I seem to remember trying it on an AE-1 Program with a Sunpak 422D that has a slow-sync feature, and although it seemed to give some indication that it might be slow-sync'ing, I recall that the shutter fired at 1/60 anyway. Only the A-1 and New F-1 bodies seem capable of taking advantage of this flash feature.<P>

 

That having been said, I don't think anything detrimental would happen by blocking contact of the two rear pins on your flash to the AE-1's hot shoe (might be easiest to do this with a piece of black electrical tape over the hot shoe contacts). These are the communication pins for the other flash features such as automatically setting the shutter speed. That way, the camera should simply fire at the shutter speed you set on the dial, and the large central contact on the hot shoe will trigger the flash. If you're really, really concerned about it, cover everything up on the hot shoe (large contact included), get a PC sync cord, and use a flash that you can plug into the PC port on the front of your camera. This will do <B>NOTHING</B> but fire the flash.

[awahlster]

I just tested this out with my AE-1 and 011A speedlite and Sunpak 1600A

 

The camera will only fire at 1/60 with a dedicated flash in the shoe

 

The camera will flash at 1/60th or slower with a non dedicated flash

 

The camera will flash at 160th or slower with the two rear contacts covered and using a dedicated flash in the shoe.

 

The only A series Canon to allow slow sync is the A-1 and then only with the 199A flash or a third party flash with slow sync option.

 

Mark W.

[weasel_bar]

Thanks all for your very informative responses. Mark, special thanks for going out of your way to try different setups. I'd like to use the flash rather than buy a new on--it was my dad's, so has sentimental value. It's also damn powerful. I flashed myself in the eyes at arms length when I was a kid, in spite of (and maybe because of) advice to the contrary. I was seeing floating red squares for several minutes.

I think I'm going to go with the tape option, and block the 2 rear contacts on the hotshoe. I looked up the trigger voltage on google, and found values ranging from 8-15 volts, so unless I decide to stick the flash into my chest and fire, I think I'm ok.

ARTIFICIAL-LOOKING CATCHLIGHTS, HERE I COME!!!

[dave_s]

Weas, does your flash have a regular PC port? If it's a Vivitar, it probably takes a very ordinary PC to Vivitar cord, yes?

 

If so, you could get the simple PC cord for like ten bucks, and have the dual advantage of (i) getting the flash off the shoe, always a Good Thing, and (ii) making it a plain undedicated flash for when you want to slow-sync.

 

But maybe I'm missin' somethin' here . . .