Camera stops firing externals flashes after a while

Sounds like the flashes are pushed to their limits. If you constantly take shots (like every 2-4 seconds) then the flashes can overheat and will need to cool down a bit every 30-40 minutes or so. After 90 min, the batteries may have run down in the flash to a point that the flash takes longer to recycle. If I remember correctly, the flash will give a beep when they are recycled and charged up for the next shot. Listen to two beeps, one from each flash before firing another shot. If the time between shot and beep gets longer, the batteries are about empty. Only use pre-charged rechargeable batteries, these can deliver more power (shorter recycle times) and stay charged longer.

If you need to shoot with short delays, try increasing iso. The flash will use a lower output and the charge isn't depleted as quickly. It'll run cooler as well. If you shoot the flashes in full manual mode, you'll need to lower the flash output too to match the exposure on the camera.

Change flash batteries after about 200 full power shots, 400 half power shots etc. If you notice they recycle slower, change the batteries. It's always handy to have multiple sets of batteries charged and ready.

All the above is assuming the triggers work flawlessly.

mapleshots wrote:

My wife is running into a pesky issue. She has a Rebel T5i with a Yongnuo YN622C trigger on it. With it she is triggering two 580EX flashes, each sitting on top of a YN622C trigger as well.

This is her description of the issue:

"I was able to shot for a while - I'd estimate about 90 minutes - but every few photos or so, one would just be pitch black and then at that point (about 90 minz), they all started being black point blank, even though all of the various flashes and flash triggers had working batteries and were firing when tested. I gave it about an hour came back, and they were still coming out black."

The occasional black shot could easily be the flashes still recharging. I'll buy that. What concerns me is the pitch black photos after 90 or so minutes of shooting products in a white box.

Since 90 minutes in both triggers and flashes are manually shooting when tested, I'm assuming it might be an issue with the camera which is admittedly not really built for heavy use. Perhaps there is some circuit protection mechanism at play?

Another interesting detail:

"When the photo just comes out black, the shutter speed sounds different. Like, it happens more slowly and is also "heavier" sounding, for lack of a better word (like if you had the shutter speedy set to, say, 1/30 or slower still, not something normal for handheld like 1/200 - 1/400), if that makes sense."

Any suggestions?