Trigger voltages of old flashguns - will they damage my 600D?

[21tones]

I have a 600D and would like to do some family portraits over Christmas. I have only used the built-in flash a couple of times for fill-in and wouldn't use it for portraits.
I do have some quite powerful Sunpak 3600 flashguns from 30 years ago which I dug out recently and was amazed to find are still working.
I have a Canon dedicated hotshoe connector for the Sunpaks but wonder whether this is safe to use with my 600D. I used to use it with my T-90 and A-1.

any suggestions on where to find answers to these questions would be helpful. I can't seem to find anything about what is safe to use on the hotshoe with the 600D, other than, obviously, Canon flash stuff.

Thanks

[atosk930]

I really can't see them harming the camera. AFAIK, I don't think the hotshoe has changed much over the years. I've used my grandpa's old flashes, which I believe are also Sunpaks. Manual control on the flash

[Old Sarge]

Several discussions, such as this one http://forums.dpreview.com/forums/thread/1393222#forum-post-15435358, have indicated the Sunpak has a trigger voltage of between 194 and 200 volts.  This could damage the circuitry of your 600D.  However, Wein makes (or used to make) a hot shoe/PC adapter which protected your camera from any damage. I believe they called it a safe-sync or something similar.  IIRC they ran about fifty dollars.

[zim]

I've have an old sunpak hammerhead, as previous poster Don't do it!
the Wein safesync is right but I decided not worth the risk even with that and got a 430

[neuroanatomist]

I really can't see them harming the camera. AFAIK, I don't think the hotshoe has changed much over the years. I've used my grandpa's old flashes, which I believe are also Sunpaks. Manual control on the flash

-1.  As pointed out, some older flash units have high trigger voltages that can damage modern cameras.  Sunpack makes/made flashes ranging from 6 V to >200 V.

http://www.botzilla.com/photo/strobeVolts.html

[emag]

I recommend you play it safe and pick up a new flash at a local shop.  Adorama / B&H carry the Wein Safe-sync for ~50$.  You don't want to risk damaging your camera while taking family portraits.

[atosk930]

Thanks for correcting me Neuro. Personally, I put my camera through hell and back in how I use it.  I'm looking for a reason to replace it. 

Never intended to cause harm to another person's gear. Good info about the voltages!

I really can't see them harming the camera. AFAIK, I don't think the hotshoe has changed much over the years. I've used my grandpa's old flashes, which I believe are also Sunpaks. Manual control on the flash

-1.  As pointed out, some older flash units have high trigger voltages that can damage modern cameras.  Sunpack makes/made flashes ranging from 6 V to >200 V.

http://www.botzilla.com/photo/strobeVolts.html

[21tones]

Thanks for your speedy and helpful responses.
I guess it's better to be safe than sorry! I might just try the Wein thing but it looks like it isn't available in the UK. It's a pity as the Sunpak's are powerful, flexible off camera guns, and it would cost a lot to get two modern equivalents.
thanks again - this place is a mine of information!

[Mt Spokane Photography]

Canon redesigned the flash system to accept up to 250 volts, so you are safe with Cameras released after the 10D and  almost all flash units.  I'd still stick to those 200v or less, or use the Wein unit.
Here is the forum thread that Canon Tech Guru Chuck Westfall confirms that all newer Digital rebels have a 250v rating.
Chuck Westfall, Director/Media & Customer Relationship, Canon USA, advises as follows regarding the flash sync circuit of the EOS Digital Rebel XT (EOS 350D):

*****
The EOS Digital Rebel XT uses a modified version of the EOS 20D's shutter unit. Consequently, acceptable trigger circuit voltage for both cameras is the same, i.e., 250 volts. Except for the original Digital Rebel, all current EOS digital SLRs (i.e., EOS-1Ds Mark II, EOS-1D Mark II, EOS 20D and EOS Digital Rebel XT) generate their X-sync signals electronically rather than mechanically. This is why they have higher acceptable trigger circuit voltage ratings than earlier models like the D30, D60, 10D and original Digital Rebel. These older models cannot be modified to achieve a higher trigger circuit voltage rating, since such a modification would require a different shutter mechanism as well as a complete redesign of the supporting circuitry.

Read the entire thread here.  Scroll down to see Chucks confirmation of this.
http://www.prophotohome.com/forum/canon-eos-digital-slr-1-6x-sensors/53600-digital-rebel-xt-350d-flash-sync-voltage-rating.html
 

[neuroanatomist]

Thanks, Mt. Spokane! 

I retract my earlier -1...   

[emag]

I, too, thank you, Mt. Spokane.  And raise a virtual Sam Adams (or Yeungling).  Salut!

[21tones]

Mt Spokane
Thanks for digging out that information. It's great news.
I'll be able to use my old Sunpak flashes now!
Even though they don't have all the modern communication with the camera it'll be easy to assess when exposures are fine with the instant feedback on the camera LCD.
Fantastic!
Thanks

[Kernuak]

Thanks for your speedy and helpful responses.
I guess it's better to be safe than sorry! I might just try the Wein thing but it looks like it isn't available in the UK. It's a pity as the Sunpak's are powerful, flexible off camera guns, and it would cost a lot to get two modern equivalents.
thanks again - this place is a mine of information!

Speedgraphic actually sell it.

http://www.speedgraphic.co.uk/cords__offcamera_control/wein_safesync_voltage_limiter_hot_shoe/10024_p.html

[Old Sarge]

Thanks for the correct information, Mt Spokane.  I feel foolish now because the 250v limit is on page 134 of my 7D manual but I guess I have overlooked it in the past.  Glad to learn about the higher limit.

[sama]

May be a way to use the old flash is to set it on an optical/wireless trigger and fire it in manual mode.