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Occasional Contributor
Posts: 8
Registered: ‎03-13-2017

5D flash sync limit with flash turned off

[ Edited ]

I recently encountered a frustrating situation with my 5DmkIII and 600EX flash.

 

Like an idiot I didn't check my flash batteries and realized they were dead when I tried using the flash. However, even with dead batteries the camera was limiting my shutter speed to 1/200. Same situation with the flash power turned on and off, shutter speed limited to 1/200. Remove the speedlite from the camera and everything is back to normal, put it back on the camera and shutter speed again limited to 1/200 (even with flash power in off position).

 

After charging the same batteries there is no shutter speed limit when the flash is powered off and attached to the camera.

 

Is there some reason why my camera would limit the shutter speed when a flash with dead batteries is on the camera?

Esteemed Contributor
Posts: 4,901
Registered: ‎08-13-2015

Re: 5D flash sync limit with flash turned off


uscpsycho wrote:

 

 

Is there some reason why my camera would limit the shutter speed when a flash with dead batteries is on the camera?


Yes, it's because the batteries are dead.  The same thing would probably happen with no batteries in the flash.  

 

Obviously, one or more of the contacts on the hot shoe allow the camera to sense when there is something mounted on the hot shoe.  Exactly how the camera does it is really not important.  Just keep your flash batteries charged up.

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"I don't rent software. I use Photoshop CS6, ACR 9.8 and Lightroom 6.8 ."
Occasional Contributor
Posts: 8
Registered: ‎03-13-2017

Re: 5D flash sync limit with flash turned off

[ Edited ]

Why on earth would the camera restrict my shutter speed when I'm clearly not using the flash?

 

I could see some weird logic for this if the flash power switch is on with dead batteries. But if the power of the flash is in the off position what difference does it make if the batteires are dead or not? Isn't it weird that the camera will let me use any shutter speed when the flash is off with charged batteries, but restrict me when the flash is off with dead batteries?

 

What is Canon's logic for that?

Esteemed Contributor
Posts: 4,901
Registered: ‎08-13-2015

Re: 5D flash sync limit with flash turned off


uscpsycho wrote:

Why on earth would the camera restrict my shutter speed when I'm clearly not using the flash?

 

I could see some weird logic for this if the flash power switch is on with dead batteries. But if the power of the flash is in the off position what difference does it make if the batteires are dead or not? Isn't it weird that the camera will let me use any shutter speed when the flash is off with charged batteries, but restrict me when the flash is off with dead batteries?

 

What is Canon's logic for that?


Wrong question.  What's the logic in mounting a device on your hot shoe that you know isn't functioning properly? 

 

You're not making sense.  "I mount this malfunctioning flash on my camera, and then my camera malfunctions, too.  Why is that?"

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"I don't rent software. I use Photoshop CS6, ACR 9.8 and Lightroom 6.8 ."
Occasional Contributor
Posts: 8
Registered: ‎03-13-2017

Re: 5D flash sync limit with flash turned off

I'll tell you the logic. Your batteries die mid-shoot/on location and you have nowhere to put the flash because you're traveling light.

 

Then what? You are forced to either dispose of the flash because you have nowhere to put it or you leave it mounted on the camera and are restricted to 1/200. What is the logic for this? Nobody would want to be in this situation.

 

if this is by design it is stupid design.

Esteemed Contributor
Posts: 3,428
Registered: ‎06-25-2014

Re: 5D flash sync limit with flash turned off


uscpsycho wrote:

I'll tell you the logic. Your batteries die mid-shoot/on location and you have nowhere to put the flash because you're traveling light.

 

Then what? You are forced to either dispose of the flash because you have nowhere to put it or you leave it mounted on the camera and are restricted to 1/200. What is the logic for this? Nobody would want to be in this situation.

 

if this is by design it is stupid design.


In principle, I agree with you. It sounds like a firmware error that should be fixed. The catch is that with the flash batteries missing or dead, the camera may have no way of telling whether the flash is turned on or off. The hot shoe can mechanically "feel" the presence of the flash unit, but the position of its on/off switch would have to be determined electrically.

Bob
Boston, Massachusetts USA
Esteemed Contributor
Posts: 4,901
Registered: ‎08-13-2015

Re: 5D flash sync limit with flash turned off

[ Edited ]

uscpsycho wrote:

I'll tell you the logic. Your batteries die mid-shoot/on location and you have nowhere to put the flash because you're traveling light.

 

Then what? You are forced to either dispose of the flash because you have nowhere to put it or you leave it mounted on the camera and are restricted to 1/200. What is the logic for this? Nobody would want to be in this situation.

 

if this is by design it is stupid design.


Charge your batteries prior to your shoot, and carry some fully charged spares..  Wear a photo vest, if you need more pockets.

 

If your flash batteries run down in the middle of a shoot, and you have no spares, then that is poor planning on your part, not a "stupid design" on Canon's part. 

 

If you get the impression that I think you complaint is petty, then you would be correct. 

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"I don't rent software. I use Photoshop CS6, ACR 9.8 and Lightroom 6.8 ."
Frequent Contributor
Posts: 69
Registered: ‎10-21-2016

Re: 5D flash sync limit with flash turned off

I don't know how exactly  the 5D senses the flash but most canon DSLRs have a microswitch built into the hot shoe, this is activated by sliding the foot of the flash into the shoe. It doesn't even have to be a flashgun, a flat piece of plastic the right size will activate the switch and as far as the camera is concerned that switch being activated means an external flash is fitted. There is not normally any intelligent sensing for this facility.

Reputable Contributor
Posts: 800
Registered: ‎02-06-2013

Re: 5D flash sync limit with flash turned off


uscpsycho wrote:

I recently encountered a frustrating situation with my 5DmkIII and 600EX flash.

 

Like an idiot I didn't check my flash batteries and realized they were dead when I tried using the flash. However, even with dead batteries the camera was limiting my shutter speed to 1/200. Same situation with the flash power turned on and off, shutter speed limited to 1/200. Remove the speedlite from the camera and everything is back to normal, put it back on the camera and shutter speed again limited to 1/200 (even with flash power in off position).

 


Strange...I need to test this with my 5DIII tonight.  Last night I was shooting with a mounted flash on my 7DII and it didn't behave this way.  With the flash mounted but turned off, there was no speed restriction.

 

 I can understand that with the flash turned on - even with dead batteries, the camera still sees it as flash on.  The batteries may be low enough not to fire but there is still some power in the system.  What I don't get is with it turned off and the camera still thinks the flash is on.  

 

In many cases I mount the flash on my 5DIII camera all the time without turning it on. I can't recall running into this problem.  I'll report tonight or later when I have the camera to test it with.

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Occasional Contributor
Posts: 8
Registered: ‎03-13-2017

Re: 5D flash sync limit with flash turned off

Waddizzle wrote:


Charge your batteries prior to your shoot, and carry some fully charged spares..  Wear a photo vest, if you need more pockets.

 

If your flash batteries run down in the middle of a shoot, and you have no spares, then that is poor planning on your part, not a "stupid design" on Canon's part. 

 

If you get the impression that I think you complaint is petty, then you would be correct. 



This is a clear design flaw. You sound like a fan boy.

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