topic Re: EOS M how to get external flash to fire in EOS DSLR & Mirrorless Cameras

EOS M how to get external flash to fire

p27159 — Tue, 27 May 2025 18:50:52 GMT

I asked this question lumped together with several other questions, but was afraid it might get lost in the shuffle so I’m going to ask again.

I am looking for information specific to the EOS M model. I have seen some things online, but not specifically for my model. The user manual was of no help. I can plug my flash into the hot shoe, and turn it on, and it lights up when it’s fully charged and ready to fire. However, no matter what settings I’ve tried, and making sure I’m in a very dark closet to test this out, the flash never fires. For right now, I’m just looking for a mode with a flash with fire for every picture I take, and then I can worry about the flash firing only if it detects it’s necessary. I’ve played around with the camera, both in automatic and manual modes, and with the INFO button, I can scroll over to the lightning bolt icon, and it doesn’t have a slash through it, so it looks like it’s enabled. If anyone can give me any ideas of why it might not be working and what I can do to fix it, would be greatly appreciated,

Re: EOS M how to get external flash to fire

deebatman316 — Tue, 27 May 2025 21:03:43 GMT

What model flash are you using and what mode are you using.

Re: EOS M how to get external flash to fire

p4pictures — Wed, 28 May 2025 14:55:14 GMT

I would check that you have the flash enabled to fire.

With the camera set to one of the creative modes - M/P/Tv/Av - press MENU and go to the first page in the RED menu section. At the end of the page is the option External Speedlite Control. Press SET and then the next level menu is displayed, the first entry is Flash firing, it must be set to Enable for the flash to work. Please check this as a first step.

Re: EOS M how to get external flash to fire

p27159 — Fri, 30 May 2025 18:03:16 GMT

Hi, thank you so much for this suggestion. It turns out it was set to DISABLED, but even after I enabled it, the flash still doesn’t fire, whether I am in manual or automatic modes,. do you have any other suggestions?

Re: EOS M how to get external flash to fire

p27159 — Fri, 30 May 2025 18:05:55 GMT

Hi, and thanks for your response. I have a very old Vivitar 2800 flash. There are a couple of different settings on it as far as selecting a shooting distance, but that’s really it. As I said, it fully charges up, and I could press the test button on the flash, and it will fire. it just doesn’t fire when I press the shutter button on the camera. I would think that most flash are standard, and if it fits into the hot tub, you’d think it would work. if you have any suggestions, other than what the other gentleman responded with already, please let me know.

Re: EOS M how to get external flash to fire

p27159 — Fri, 30 May 2025 18:07:32 GMT

I forgot to answer your other question. I’ve tried this on both automatic and manual modes, with a shutter speed of 1/60 of a second in manual mode

Re: EOS M how to get external flash to fire

p27159 — Fri, 30 May 2025 18:12:07 GMT

I just noticed one other thing when playing around with the speed lite sub menu that you told me about. I went into the flash function settings, and it says “this menu cannot be displayed. Incompatible flash or flash’s power is turned off.” I think this answers my question that my flash must be incompatible. But when I go online to try to find a new flash, how would I know whether what I’m buying is compatible or not?

Re: EOS M how to get external flash to fire

deebatman316 — Fri, 30 May 2025 18:22:41 GMT

Very old flashes put out very high voltage on the hot shoe. This can burn out the camera’s flash circuitry. Or the flash won’t fire at all. I would use a Canon EX series speedlite to see if it will fire. Any Canon flash ending in EX will work. Such as 220EX, 430EX III-RT & 600EX II-RT flashes will work. The in camera flash menu only works with Canon flashes. It doesn’t work with old flashes such as the old Vivitar flash or any other manual flash unit.

Re: EOS M how to get external flash to fire

p27159 — Sat, 31 May 2025 02:46:38 GMT

Thanks. I hope I didn’t damage the flash circuit by trying that old flash for a while. So you’re saying that a flash that may not be a Canon brand, but is referred to as “speedlite” and claims it’s compatible with Canon, may not work with the menus, but i’m wondering if they will work at all. I was looking for a relatively compact flash unit, which I know isn’t going to light up a large dark room, and the only ones I saw from Canon were rather large and just about as big as the camera itself.

Re: EOS M how to get external flash to fire

p4pictures — Sat, 31 May 2025 13:30:01 GMT

Old Vivitar flashes were know to have very high trigger voltages and prone to destroying camera electronics. Most modern cameras have protection against such voltages, but it means the flash will not fire.

I suggest that you try a Canon Speedlite such as the Speedlite EL-100 or Speedlite 430EX III-RT on your camera both as a test to make sure the camera is still working and able to fire a flash, plus these two units will give you an idea of the balance of them with your camera.

Re: EOS M how to get external flash to fire

p27159 — Sat, 31 May 2025 19:25:31 GMT

Brian, thank you so much for all the time you’ve taken to respond to my comments. I had already placed an order to have a small flash device delivered, as I said, it claimed it was a compatible device, but not made by Canon specifically. It just arrived, and I attached it to my camera, and as discussed previously, that menu option Doesn’t work with it, but I was able to get it to successfully work. Therefore, I think this issue is now closed, unless you have any other further remarks. Thanks again for all the help you’ve given me, it is really appreciated. I think it’s amazing that people like you post on these boards in your own time with no compensation, just to be helpful.

Re: EOS M how to get external flash to fire

deebatman316 — Sat, 31 May 2025 19:43:28 GMT

3rd Party compatibility is up to the 3rd Party manufacturer when it comes to flashes that talk to the camera for autoexposure. All Manual flash units are usually compatible. All they need to work is a signal from the camera to fire no other communication is needed. Once autoexposure comes in then compatibility can be hit or miss. Usually 3rd Party flash units are made to be compatible with certain brands. Every manufacturer implements their own flash protocols differently. Canon's E-TTL flash system is NOT cross compatible with Pentax's (P-TTL flash system), Nikon's (i-TTL flash system) or Sony/ Minolta's (ADI/ pre-flash TTL flash system). Manual flash units are manually set that's why they're compatible with all brands. Once flash autoexposure comes in its a much different story.

Re: EOS M how to get external flash to fire

p27159 — Sat, 31 May 2025 20:48:19 GMT

Demetrius, thanks again for your comments, which make perfect sense to me. I also want to thank you for taking the time to be so helpful on a forum like this!

Re: EOS M how to get external flash to fire

deebatman316 — Sat, 31 May 2025 21:25:15 GMT

You can use any Canon EX Series speedlite or EL-1 & EL-100 speedlites. Just avoid very old film era Canon speedlites those usually end in E/ EZ/ G & TL. These speedlites use a different and INCOMPATIBLE flash system designed for film cameras. You don't have to get the newest Canon speedlite for your camera. Older Canon EX series speedlites are compatible but the in camera flash menu is NOT COMPATIBLE with older speedlites. They'll show the same "Incompatible Flash" message but this should be ignored. The flash is still working correctly it just doesn't support the new 2 way flash communication that was added in 2007. Older flash units will have to have settings changed directly on the flash itself. Also the camera will show items grayed out or missing when looking at the flash settings menu. The picture below shows what happens when an older Canon EX series flash is mounted in the hot shoe. In this case I had the Canon 550EX mounted in the hot shoe. The 2nd picture is a picture of a newer flash unit mounted in the hot shoe which is a Canon 600EX II-RT. All settings are settable from the camera with newer speedlites. I own a mix of old and new speedlites and they all work as designed.

Flash Function Settings screen