Problem with MT-24EX Twin Flash Control

I have an odd problem.

I set hi-speed sync today but when I went to use it had gone back to standard sync mode and now I cannot set Hi-Speed sync at all.

Normally you press the +&- buttons together to around different sync modes; First-Curtain, Hi-speed, Second-Curtain.

Now it just cycles between First-Curtain and Second-Curtain.

Any one had this issue or any ideas?

Lester not a specific answer but just in case you have not tried it, I have had to take the batteries out of another canon flash for an hour or so to get it back to normal behaviour.

Brian V.

Hi Lester

I find that if I set a funky setting such as "Silent Shutter" on e.g. my Canon EOS-R, this can cause a previous normally operating functionality to disappear (become not available) until I "Undo" my funky setting.

So, have you made any Custom changes in-between?

Cheers

Dennis

Thanks for looking in folks.

So although I must have used this setting on four Canon bodies in the past this issue is on the 7DII,

An update is although off the camera (and removing the batteries for some mins but not an hour) I still could not get the functionality.

Then I mounted it on the camera, fiddled a bit and it started work.

Then something I did stopped it working, and the something else started it working.

I am not sure what the something was!

I am using the camera on the C1 setting which is average metering, AV, centre focus point.

I note that the hi-speed sync is not available on B type cameras (all my cameras are A type).

Working Hypothesis A: A Communication problem between flash and camera puts the flash into a odd firmware mode where it thinks it is on a type A camera.

Working Hypothesis B: Something in the camera setting is confusing it.


I normally store the flash with the batteries out, this does seem to loose the CF settings, so I might leave the batteries out for a while and see if it plays up. I'll check it before I do that.

Update:

So after leaving the batteries out for 30-45 min the unmounted flash reverted to normal operation.

I then mounted the flash, turned on the flash turned on the camera and reproduced the problem.

Turn off camera, turn off flash after getting it in normal mode. Turn on camera turn on flash hi speed sync selectable and worked ok.

Now I am sure I have not had this issue with other cameras, so it may be a conflict between the camera and flash modes with the more advanced 7DII flash setting menu, if the flash is turned on first.

Avoidance action: Turn camera on before flash and flash off before camera off. (latter may not be 100% needed).

Faster corrective action: Put flash mode normal and turn off flash and camera then start again as above. If all else fails remove the flash batteries for a while.

Lester Wareham wrote in post #19052495
Thanks for looking in folks.

So although I must have used this setting on four Canon bodies in the past this issue is on the 7DII,

An update is although off the camera (and removing the batteries for some mins but not an hour) I still could not get the functionality.

Then I mounted it on the camera, fiddled a bit and it started work.

Then something I did stopped it working, and the something else started it working.

I am not sure what the something was!

I am using the camera on the C1 setting which is average metering, AV, centre focus point.

I note that the hi-speed sync is not available on B type cameras (all my cameras are A type).

Working Hypothesis A: A Communication problem between flash and camera puts the flash into a odd firmware mode where it thinks it is on a type A camera.

Working Hypothesis B: Something in the camera setting is confusing it.


I normally store the flash with the batteries out, this does seem to loose the CF settings, so I might leave the batteries out for a while and see if it plays up. I'll check it before I do that.

Update:

So after leaving the batteries out for 30-45 min the unmounted flash reverted to normal operation.

I then mounted the flash, turned on the flash turned on the camera and reproduced the problem.

Turn off camera, turn off flash after getting it in normal mode. Turn on camera turn on flash hi speed sync selectable and worked ok.

Now I am sure I have not had this issue with other cameras, so it may be a conflict between the camera and flash modes with the more advanced 7DII flash setting menu, if the flash is turned on first.

Avoidance action: Turn camera on before flash and flash off before camera off. (latter may not be 100% needed).

Faster corrective action: Put flash mode normal and turn off flash and camera then start again as above. If all else fails remove the flash batteries for a while.

Perhaps your flash, when it is turned on first, puts itself in 'TTL' mode (for film cameras with TTL flash metering) in which it merely looks for a 'trigger', and in that mode it is dumb about preflash and digital flash power commands from the camera. It is ignorant about receiving an 'HSS flash mode' command.
By turning on the camera first, the flash detects it is mounted on an eTTL camera when it is first turned on, so it operates properly.

Wilt wrote in post #19052616
Perhaps your flash, when it is turned on first, puts itself in 'TTL' mode (for film cameras with TTL flash metering) in which it merely looks for a 'trigger', and in that mode it is dumb about preflash and digital flash power commands from the camera. It is ignorant about receiving an 'HSS flash mode' command.
By turning on the camera first, the flash detects it is mounted on an eTTL camera when it is first turned on, so it operates properly.

Could be (see hypothesis A above) but the problem with that idea is it gets stuck even if dismounted from the camera.

I'm pretty sure that if you are using the camera's ability to control / configure the flash it will override the settings on the flash, and from your description of the symptoms it sounds like that's what's happening. I always control the flash settings with the camera after adding flash control to my quick access menu.

Also make sure that the MT-24EX is seated properly in the hot shoe and that the tension ring is tight (just don't over tighten it). I had issues with mine where the electrical contacts weren't lining up properly and the flash would dump out so much power when it fired I probably genetically altered what I was shooting

The MT-26EX RT has the new flash locking mechanism that Canon is using on all of it's standard flash units.

Lester Wareham wrote in post #19052773
Could be (see hypothesis A above) but the problem with that idea is it gets stuck even if dismounted from the camera.

The flash has to SENSE it is mounted on eTTL camera in order for it to SWITCH! There ought to be some visual indicator of TTL vs eTTL mode of the flash itself on its LCD.

Also, eTTL flash units can be somewhat finicky about being mounted on the hotshoe with POWER OFF, and then switched on after everthing is tightened....and then the camera itself needs to be awake, so the flash communicates with it in order to go into eTTL mode (not TTL).
As described by Dalantech, Canon eTTL can be very finicky, and the 'always full power' is from not sensing it is on an eTTL camera so it goes to TTL mode expecting a 'quench' signal from a TTL film camera.
HSS requires camera and flash have bidirectional eTTL connectivity so the flash gets put into HSS when the shutter speed is too high for X-sync to work properly.

Dalantech wrote in post #19053038
I'm pretty sure that if you are using the camera's ability to control / configure the flash it will override the settings on the flash, and from your description of the symptoms it sounds like that's what's happening. I always control the flash settings with the camera after adding flash control to my quick access menu.

Also make sure that the MT-24EX is seated properly in the hot shoe and that the tension ring is tight (just don't over tighten it). I had issues with mine where the electrical contacts weren't lining up properly and the flash would dump out so much power when it fired I probably genetically altered what I was shooting

The MT-26EX RT has the new flash locking mechanism that Canon is using on all of it's standard flash units.

Interestingly I tried the camera flash menu when it was malfunctioning and the menu said the flash was not compatible.

Not checked it since resolving the problem.

Lester Wareham wrote in post #19053286
Interestingly I tried the camera flash menu when it was malfunctioning and the menu said the flash was not compatible.

Not checked it since resolving the problem.

This is indicative of the fact that the eTTL camera does not have a communication with an eTTL compatible flash unit...which could be because of bad connection via the hotshoe, and/or because the flash is in 'TTL' mode rather than switching to 'eTTL' mode.

Lester Wareham wrote in post #19053286
Interestingly I tried the camera flash menu when it was malfunctioning and the menu said the flash was not compatible.

Not checked it since resolving the problem.

I remember seeing a similar error with my copy of the MT-24EX and it was due to the flash not making a good electrical contact with the camera.

Certainly could be, but I was able to reproduce the problem by power up order, I'll try it on my other bodies and see how it reacts.

ok, I tried to reproduce this again and cannot, this suggest something intermittent most probably the camera-flash connection.