Why NO picture files?

[ajax]

I'm hoping that more experienced photographers can explain something that I haven't been able to figure out. When using an external flash mounted on the camera, how is it possible to trigger that flash without triggering the shutter and taking a picture?

I recently experienced a very strange result, at least to me, when trying to photograph a good size group of people. To be honest I'm a bit of a novice when it comes to using modern digital cameras. As such, I have no idea whether or NOT it matters but the equipment involved in this incident is a Canon EOS R mirrorless camera with a Canon RF 24-105mm F4 L IS USM lens and a Canon Speedlite EL-100 flash.

The scene for the photograph I was wanting to take was outdoors, after sunset, on a hotel patio which had some but limited lighting. There was a group of, between 50 and 60, people with the camera equipment attached to a tripod and positioned on a deck about one story above the group. Both the camera and the flash were set in fully automatic mode. The picture was composed and the live view on the display screen showed a picture that would have been acceptable even though NOT great because of the limited amount of light.

As it turned out I also was part of the group so I asked someone else to take the picture (i.e., press the shutter release button). While I cannot be absolutely certain that the shutter release button was used as expected I am certain that the flash was discharged as expected. This was done several times in a effort to obtain multiple raw files (pictures) to choose from given that you never get pictures of groups where everyone likes how they look.

However, when I went to retrieve the raw files for post processing there were none.

[Manfred M]

Without seeing the metadata generated by the camera on the blank exposures, we are limited to educated guesses as to what went wrong for you. That should be attached to the black frames that you recorded and would tell you the camera's ISO, shutter speed and aperture settings, including confirmation that the flash did fire.

Given your description, my guess is that the flash was not able to throw out enough light to illuminate the scene. Standing one story above the group suggests you and your flash were quite some distance away from the group being photographed. Speedlites don't throw out a lot of light (then tend to be powered by either 2 or 4 AA batteries).

In an outdoor shot, the flash will diffuse in all directions and very little of the light from the flash will fall on the subject; likely far too little to impact the exposure. Your camera amplifies the available light that enables you to see something on the screen; but that does not mean that there is enough light to properly expose the scene.

What flash photographers do to capture that type of scene is use off-camera techniques, where the flash is removed from the camera and placed close to the subjects using a light stand. The flash would be fired using radio triggers; multiple flash units would likely be needed to light the scene properly.

[ajax]

Looks like I didn't use the word record but what I meant was that nothing was recorded. There were NO files on the SD card. The lighting was bad but there was an image being displayed in live view with NO light from the flash. I'd also previously succeeded in taking a test shot of the scene absent the people just to see what I'd get under those conditions. That worked as expected.

I've made various attempts to consciously cause this to happen. In that, go outside at night and try to trigger the flash without recording a file but I haven't been able to do it. I'm looking for an explanation of how that can happen even if amounts to doing something very weird when it comes to operating the camera.

[pnodrog]

Is it possible that the video button was pressed instead of the shutter release button? I don't know whether in certain setting that would fire the flash? However to someone unfamiliar with a DSLR or mirrorless camera glancing down at the top of the camera the video button may look the most important.

[ajax]

I definitely thought it could be attributed to pressing the wrong button or even failing to finish pressing the Shutter button. My camera also has some other buttons like a Multi-function button plus another button to Lock it and something called an LCD panel info switching/ illumination button. My experimenting included pushing those buttons but I couldn't get anything to discharge the flash other the fully pressing the Shutter button that does result in recording a file. In the case of my experiments the associated images were very black even with the flash.

Another thought I had is what happens when Auto Focus is on but the camera cannot focus? I haven't figured out to know with any certainty when that might happen. However, my experiments were performed in a much darker setting than was associated with the failed attempts to photograph the Group.

[pnodrog]

Is it possible that someone who only uses a cell phone pressed a button on the flash? You may need to get the "photographer " to demonstrate what they did to take the photo.

[Manfred M]

Thanks for the update.

There are only two ways of firing an on-camera Speedlite. One is when the camera actuates it, by using the shutter release (or the camera's, self timer), which is what you would have expected. The other way is by pushing the "test" button on the Speedlite itself.

I suspect Paul is right and this is what happened.

[Stagecoach]

You say that the "camera and flash were set in a fully automatic mode" and that "I am certain that the flash was discharged as expected".

Could it have been a situation where the camera/flash set off a 'pre flash/flash assist' to allow/help it to focus, it didn't focus so did not take the shot? Was what you saw the 'flash assist' output?

Edit 1 - Whilst not a familiar with Canon the above is made on the assumption that the mirrorless does not recognize the conventional IR focus assist as used with DSLRs so likely that this has been overcome by use of a pre flash instead.

Edit 2 - In post No 5 you say "In the case of my experiments the associated images were very black even with the flash." Is a possible explanation for this that focus was attained by use of the pre flash, but your exposure was too low?

[ajax]

Manfred's description of how my Canon camera works is how I thought it should work. The difference in opinion is that Manfred has much more reason to be confident than I do.

[ajax]

Is it possible that someone who only uses a cell phone pressed a button on the flash? You may need to get the "photographer " to demonstrate what they did to take the photo.

This is someone who very well may only take pictures with their phone. It was also pretty dark where the camera was located and possible that my attempt to show him the Shutter release button was unclear. My theory was that pushing the wrong button was the logical explanation but I was unable to duplicate the result in my experiments pushing the wrong button.

It don't see any kind of button on my Speedlite EL-100 flash other than turn it on or off.

[ajax]

Per Grahame's reply, for me "discharged as expected" only meant that I expected the flash to discharge based on the light conditions and it did.

Having thought about it a little more I am thinking that this is a case where manual focus would have made more sense and been a better choice. Worth remembering for next opportunity. Per Grahame's Edit 2, my experiments did include the idea that if AF would trigger the flash when partially pressing the Shutter release button that could explain what happened. In that, the person pushing the button would think that the picture was taken and therefore NOT followed through by pushing the Shutter button the rest of the way down. With that said, I couldn't make that happen when experimenting. Of course auto focus probably counts as a form of artificial intelligence and I couldn't recreate the same scene conditions (i.e., lighting) for my experiments. I am pretty sure there was less rather than more light for these experiments.

[odds]

...There were NO files on the SD card

Which likely means the shutter was not activated.

Pre-flash has been mentioned in the thread, but pre-flash (for exposure control) is normally triggered by the shutter.

There is, depending on settings, also a red-eye type of pre-flash that typically fires at a shutter half-press point. Is it possible that your assistant pressed the shutter button half way only and that you observed red-eye pre-flash?

Edited to add:
The Canon Speedlite EL-100 manual indicates that pressing the FE Lock button triggers a pre-flash (for exposure control)

--
OddS

[Stagecoach]

Pre-flash has been mentioned in the thread, but pre-flash (for exposure control) is normally triggered by the shutter.

Reading through the EL-100 Speedlite manual pdf version page 25 there is reference to it's AF Assist Beam which mentions that 'intermittent flashes are automatically emitted to assist with autofocusing'.

Whilst there's lots of info around regarding this, that refer to it as 'pre-fires for AF Assist', unfortunately I can't find any reference as to when it is fired, half press or full press activating shutter. But thinking about it, An AF assist light is normally activated when you focus e.g using half shutter press or rear button AF-ON.

If this has something to do with what has occurred, and it is what was seen, I wonder what the situation is if the camera is set to 'Single Shot' and only if Focus is detected?

[odds]

...EL-100 Speedlite manual pdf version page 25

There is also page 24 that deals with "FEL: FE Lock": The Speedlite fires a preflash, and the flash exposure is locked. A note at the bottom of the page: On some cameras, each press of the FE Lock button switches between firing a preflash and unlocking flash exposure..

--
OddS

[Manfred M]

Does anyone other than me regularly shoot with flash? Whether it be small flash (a.k.a. speedlights) or studio flash, I use these tools in my work all the time; I shoot more flash images than existing light images...

Now I don't use Canon and I don't use a mirrorless camera with flash, so I could be wrong on a few points.

The comments on the last few threads seem to be about the autofocus illumination. In my small flash (both Nikon and current model Godox), these are red lights and come on intermittently, while the camera seeks focus. My camera also has a white autofocus illumination light built in, which has much the same purpose. It does not work if a speedlight is mounted on the hot shoe. These lights do not look anything like a pre-flash from the speedlight and are unlikely to be mistaken as being such.

In my cameras, when in automatic exposure mode, the timing between the pre-flash and actual flash are very close together, to the point most people will not realize that the unit actually flashes twice. When I teach flash photography, I will set my camera to second shutter / second curtain mode so people can actually observe this is happening. The pre-flash determines exposure, so yes, it does lock in the exposure at that point.

The only time we actually see two flashes is when red-eye reduction is turned on. Here there is a brief flash, a short wait for the irises in the subject's eyes to close down, followed by the pre-flash and main flash.

What I don't know is if the pre-flash determines there is not enough light for a correct exposure and thus prevents the shutter from firing. This would certainly result in what David has seen; he sees a flash, but there are no images recorded (i.e. no shutter actuations). Given the shooting conditions (after sunset) and distance from the subjects, it is highly likely that there isn't enough light for a good exposure. If the camera determines it can't get a good shot, the shutter would not activate, hence no shots recorded. I suspect this feature (assuming it exists) can be overridden.

[Rufus]

Just a thought, and taking on board the possibility of pressing the wrong button, my Canon EX-580 speedflash unit has a test button which lights up red when it is charged and ready to fire. That woud be easy to see in low light and will fire the flash but does not does not result in an exposure. It is not a mistake a photographer would make but could that be the reason? Having said that, the light goes out after a while.

[Stagecoach]

Does anyone other than me regularly shoot with flash? Whether it be small flash (a.k.a. speedlights) or studio flash, I use these tools in my work all the time; I shoot more flash images than existing light images...

Now I don't use Canon and I don't use a mirrorless camera with flash, so I could be wrong on a few points.

The comments on the last few threads seem to be about the autofocus illumination. In my small flash (both Nikon and current model Godox), these are red lights and come on intermittently, while the camera seeks focus. My camera also has a white autofocus illumination light built in, which has much the same purpose. It does not work if a speedlight is mounted on the hot shoe. These lights do not look anything like a pre-flash from the speedlight and are unlikely to be mistaken as being such.

I don't use Canon, but I use a lot of Nikon Speedlite flash with mirrorless and what I do know is that with mirrorless the older conventional 'red light' for AF assist is not effective.

From info gathered Canon R series mirrorless has provided facility to have the Canon Speedlite emit a pre-flash/intermittent flash from the Speedlite if it considers the scene too dark for the camera tiny LED AF assist light.

[Manfred M]

I don't use Canon, but I use a lot of Nikon Speedlite flash with mirrorless and what I do know is that with mirrorless the older conventional 'red light' for AF assist is not effective.

Agreed, which is why I have disabled it. It is really annoying to the subject or anyone else looking toward the camera.

From info gathered Canon R series mirrorless has provided facility to have the Canon Speedlite emit a pre-flash/intermittent flash from the Speedlite if it considers the scene too dark for the camera tiny LED AF assist light.

Which would explain why David saw the flash. Sounds like another useless feature that deserves to be disabled.

[Stagecoach]

Agreed, which is why I have disabled it. It is really annoying to the subject or anyone else looking toward the camera.

Whilst you may have disabled it for those reasons you are using a DSLR. It's ineffectiveness with respect to mirrorless is that it can not be recognized, not how annoying it can be.

Which would explain why David saw the flash. Sounds like another useless feature that deserves to be disabled.

Surely you can hardly call a feature that assists you achieving focus in very low light situations when using mirrorless "useless".

[pschlute]

I sometimes wonder how anyone was able to focus at all 20+ years ago