Flash question

I picked up a flash today at the local good will. it's the Maxwell m500C-zoom.
I have a 40-D and wanted to see if anyone knows if this flash is compatible... i would hate to stick it on there and it screw something up lol.
thanks in advance
Audra

as far as i know you can only use the ( EX speedlights )not sure

No, there are all kinds of flashes you can use on EOS cameras. The problem with non-EX speedlites (or 3rd party specifically designed for E-TTL-II) is that they will not work with the metering system so you're stuck to either the manual power settings if available or maybe just firing at full power (don't know the unit you're talking about)

However, some older flashes have very high trigger voltages which can damage cameras. I doubt this will be a problem with the 40D but do some googling on the trigger voltage of the flash and what your camera can take before you try it out.

I put a couple of test leads across the cable, once it charges up there is 240 volts across that cable.

Accidentally grounded out the center pin to the outer sleeve and instant flash, so we are looking at a 240 volt trigger voltage.

Should this be used on the 40d? Or did I measure that completely wrong.

flyingwolf wrote in post #5219217
I put a couple of test leads across the cable, once it charges up there is 240 volts across that cable.

Accidentally grounded out the center pin to the outer sleeve and instant flash, so we are looking at a 240 volt trigger voltage.

Should this be used on the 40d? Or did I measure that completely wrong.

Canon 40D can not handle 240 volts, at least not more than once. Search the Flash forum there are threads there with links to sites showing compatibility of camera to flashes.

Was I measuring this right?
I was measuring across the sync cord.
I was assuming the outer sleeve was ground and the inner pin was hot.

When the flash was ready to fie it measured 240 volts, is that the correct way of measuring it.

flyingwolf wrote in post #5219397
Was I measuring this right?
I was measuring across the sync cord.
I was assuming the outer sleeve was ground and the inner pin was hot.

When the flash was ready to fie it measured 240 volts, is that the correct way of measuring it.

Yes, that should be the correct place to measure for voltage. I measured from the hot shoe connectors on the bottom of the flash, as it was easier than the sync cord.

Ok after somemore testing it is an older flash and it is indeed powering up to 240 volts.
So with that in mind its time to grab remote trigger and use it for all its worth

flyingwolf wrote in post #5219696
Ok after somemore testing it is an older flash and it is indeed powering up to 240 volts.
So with that in mind its time to grab remote trigger and use it for all its worth

That's what I use mine for, just need one more remove trigger for the second flash.

flyingwolf wrote in post #5219217
I put a couple of test leads across the cable, once it charges up there is 240 volts across that cable.

Accidentally grounded out the center pin to the outer sleeve and instant flash, so we are looking at a 240 volt trigger voltage.

Should this be used on the 40d? Or did I measure that completely wrong.

You need an adapter to safely uses flashes like this on a Canon DSLR. The high trigger voltages can damage the camera electronics.