7D & pop-up flash for fill flash

My friend has told me that when using the 7D in M mode, the flash exposure will not be metered for fill and that you need to use the camera in Av mode in order to have the camera meter for the fill flash exposure. Is this true?

I had a recent photoshoot and found that I needed to use -2 FEC while I was shooting in M mode. This seemed really odd as I thought the camera would have metered for the fill flash exposure automatically, but it was resulting in ghastly overexposure.

This seems like a shortcoming in my mind. Does Nikon's system do the same thing or did they figure out that people would want to work in M mode but retain autoexposure for fill flash? Or is this a shortcoming of the pop-up flash and would an external flash handle the situation properly?

There's nothing "automatic" in Manual mode...

You set the shutter, the aperture and you adjust the flash power or flash to subject distance to achieve the proper exposure.

That's rather disappointing and annoying.

Well, are you really in full manual or (if the 7D pop up allows) are you in ETTL?

In ETTL, you set the first two parameters and the camera will try to get the exposure right but there are mitigating factors. Subject / Background Vs Metering Pattern is a biggie. If your subject is surrounded by black and your metering pattern can "see" all that black, the camera will "think" you have a very dark subject and will try to blow enough light to compensate for that.

The obverse is true if your subject is surrounded by white .. You'll get a very under-exposed image.

The biggest limitation really is the power to distance ratio (or lack thereof) with any pop up flash. Beyond more than about 5', you're asking it to do more than it's truly capable of doing.

Better bet is to invest in a good flash that can go in the hotshoe or be controlled off camera (which is the bonus functionality of the 7D!)

When the camera is in manual mode, the flash can remain in ETTL (that's independently selectable in the Flash control menu, page 115 of the manual). I took one shot in Av and duplicated the shutter speed and aperture in manual mode and the exposures according to the histograms were virtually identical. If in ETTL and I have a lot of dark or light reflectance in the frame, I'll use FEL (using the center spot in the viewfinder) on a neutral tone and then take the shot.

To summarize, if you're in ETTL, regardless of the camera's mode, the flash will either provide most of the illumination if the scene is dark or varying degrees of fill if the scene is well lit. To have to have had -2 FEC when in ETTL, your camera must have metered on a very dark portion of the scene.

Poe wrote in post #12250831
That's rather disappointing and annoying.

That's the good thing about manual,, you take full control and not allow your camera to dictate terms..

Here's what you do.. Put your camera including ISO to manual.. Meter the subject then in your camera's flash menu select -2 in the flash exposure compensation.. You can also try any flash exposure compensation setting depending on the effect you desire..

FlyingPhotog wrote in post #12250853
Well, are you really in full manual or (if the 7D pop up allows) are you in ETTL?

In ETTL, you set the first two parameters and the camera will try to get the exposure right but there are mitigating factors. Subject / Background Vs Metering Pattern is a biggie. If your subject is surrounded by black and your metering pattern can "see" all that black, the camera will "think" you have a very dark subject and will try to blow enough light to compensate for that.

The obverse is true if your subject is surrounded by white .. You'll get a very under-exposed image.

The biggest limitation really is the power to distance ratio (or lack thereof) with any pop up flash. Beyond more than about 5', you're asking it to do more than it's truly capable of doing.

Better bet is to invest in a good flash that can go in the hotshoe or be controlled off camera (which is the bonus functionality of the 7D!)

My understanding is that the ambient meter reading does not affect the flash exposure metering. It's not until the flash fires that the camera, when using ETTL, begins to adjust the flash power. So it wouldn't matter what my subject is surrounded by until I press trigger the shutter and then the flash.

oldvultureface wrote in post #12251473
When the camera is in manual mode, the flash can remain in ETTL (that's independently selectable in the Flash control menu, page 115 of the manual). I took one shot in Av and duplicated the shutter speed and aperture in manual mode and the exposures according to the histograms were virtually identical. If in ETTL and I have a lot of dark or light reflectance in the frame, I'll use FEL (using the center spot in the viewfinder) on a neutral tone and then take the shot.

To summarize, if you're in ETTL, regardless of the camera's mode, the flash will either provide most of the illumination if the scene is dark or varying degrees of fill if the scene is well lit. To have to have had -2 FEC when in ETTL, your camera must have metered on a very dark portion of the scene.

The flash was set to ETTL II and evaluative metering - so it should be adjusting the flash power automatically according to the camera's exposure protocol. I'll have to experiment more with evaluative and average metering + FEL.

The flash is being adjusted automatically... whether the camera is in M or Av mode (unless you have the flash set to M, too... have eTTL turned off... then it's purely manual and you are responsible for making all the correct settings yourself).

Read up on flash... Lots of links here: https://photography-on-the.net/forum/showthre​ad.php?t=138907

Short version, this is how eTTL works...

In any of the auto exposure modes, the flash acts as "fill".

In the manual mode, flash is treated as "full".

What this means is that in Av (or Tv or P) the flash is treated as "fill" or secondary lighting. The camera first adjusts the exposure settings for the ambient lighting conditions, treating ambient light as the primary light source. Secondarily, some reduced amount of flash is added as needed. You can still adjust the flash output +/- to make the fill effect stronger or weaker, as needed.

In M mode the flash is treated as the primary or "full" light souce and ambient light is mostly igrnored (it has to be... it's M as in "Manual" mode, after all). The camera takes the shot based upon providing enough flash to fully illuminate the subject... and it's still automatic so long as you have the flash set to eTTL mode. You can dial the flash +/- as needed to make it stronger or weaker.

Now, even when using flash in M/full, you can make it act as fill. But since the camera is in Manual mode, you have to set up the exposure yourself. If you set the camera to make most or all the exposure with ambient light... guess what, flash will not be very strong because not much additional light is needed. That's essentially "fill", except this time you are controlling it more closely.

Frankly, this is the way all TTL metered flash has to work on all cameras, although I'm sure there are some nuance differences.

Another point to remember with flash used with the camera set manually is that the flash's short duration (about 1/750 second is typical) in effect "becomes your shutter".... The shutter speed you set doesn't really matter, so long as it's the camera's flash sync speed or slower (7D's is 1/250, 5DII is 1/200). You control the strength of the flash... how far it reaches... with your aperture setting.

You mentioned using -2 FEC and still getting blown out images.... You should have stopped down your aperture, but also could have reduced your ISO.

There are also some nuance differences to using flash as fill in Av, Tv or P. There are more explanations at the links referenced above.

Now, I have to say that I really don't know exactly how to set up the built in flash on my 7Ds to operate in either of these modes. I've never used built in flash on the camaeras and likely never will, because built in flashes are pretty useless... Maybe okay for quick use in an emergency when I don't have a much better accessory flash with me, in which case I'd probably just switch to Av.

Built in flashes are weak, use up battery charge rapidly (that I'd rather have available to keep taking shots), recycle slowly , overheat and shut down when used hard for fast shooting situations, often are partially blocked by larger lens hoods and are in the worst possible location for both redeye and ugly shadows. I'll use an accesssory flash, usually on a bracket and connected via an off camera show cord for better shadow effects and to minimize redeye. I really can't recall the last time I used a built in flash on any SLR camera that has one.

Poe wrote in post #12250794
My friend has told me that when using the 7D in M mode, the flash exposure will not be metered for fill and that you need to use the camera in Av mode in order to have the camera meter for the fill flash exposure. Is this true?

I had a recent photoshoot and found that I needed to use -2 FEC while I was shooting in M mode. This seemed really odd as I thought the camera would have metered for the fill flash exposure automatically, but it was resulting in ghastly overexposure.

This seems like a shortcoming in my mind. Does Nikon's system do the same thing or did they figure out that people would want to work in M mode but retain autoexposure for fill flash? Or is this a shortcoming of the pop-up flash and would an external flash handle the situation properly?

amfoto1 wrote in post #12252493
The flash is being adjusted automatically... whether the camera is in M or Av mode (unless you have the flash set to M, too... have eTTL turned off... then it's purely manual and you are responsible for making all the correct settings yourself).

Read up on flash... Lots of links here: https://photography-on-the.net/forum/showthre​ad.php?t=138907

Short version, this is how it works...

In any of the auto exposure modes, the flash acts as "fill".

In the manual mode, flash is treated as "full".

What this means is that in Av (or Tv or P) the flash is treated as "fill" or secondary lighting. The camera first adjusts the exposure settings for the ambient lighting conditions, treating ambient light as the primary light source. Secondarily, some reduced amount of flash is added as needed. You can still adjust the flash output +/- to make the fill effect stronger or weaker, as needed.

In M mode the flash is treated as the primary or "full" light souce and ambient light is mostly igrnored (it has to be... it's M as in "Manual" mode, after all). The camera takes the shot based upon providing enough flash to fully illuminate the subject... and it's still automatic so long as you have the flash set to eTTL mode. You can dial the flash +/- as needed to make it stronger or weaker.

Now, even when using flash in M/full, you can make it act as fill. But since the camera is in Manual mode, you have to set up the exposure yourself. If you set the camera to make most or all the exposure with ambient light... guess what, flash will not be very strong because not much additional light is needed. That's essentially "fill", except this time you are controlling it more closely.

Frankly, this is the way all TTL metered flash has to work on all cameras, although I'm sure there are some nuance differences.

There are also some nuance differences to using flash as fill in Av, Tv or P. There are more explanations at the links referenced above.

And, I really don't know exactly how to set up the built in flash on my 7Ds to operate in either of these modes. I've never used it and likely never will, because built in flashes are pretty useless... Maybe useful for quick use in an emergency when I don't have a much better accessory flash with me.

Built in flashes are weak, use up battery charge rapidly (that I'd rather have available to keep taking shots), recycle slowly , overheat and shut down when used hard for fast shooting situations, often are partially blocked by larger lens hoods and are in the worst possible location for both redeye and ugly shadows. I'll use an accesssory flash, usually on a bracket and connected via an off camera show cord for better shadow effects and to minimize redeye. I really can't recall the last time I used a built in flash on any SLR camera that has one.

a good flash write-up ^^^

But if you were on a planned photoshoot why use the pop-up? A regular flash (even cheap yongnuo) is so much better than the pop-up flash!

amfoto1 wrote in post #12252493
The flash is being adjusted automatically... whether the camera is in M or Av mode (unless you have the flash set to M, too... have eTTL turned off... then it's purely manual and you are responsible for making all the correct settings yourself).

Read up on flash... Lots of links here: https://photography-on-the.net/forum/showthre​ad.php?t=138907

Short version, this is how eTTL works...

In any of the auto exposure modes, the flash acts as "fill".

In the manual mode, flash is treated as "full".

What this means is that in Av (or Tv or P) the flash is treated as "fill" or secondary lighting. The camera first adjusts the exposure settings for the ambient lighting conditions, treating ambient light as the primary light source. Secondarily, some reduced amount of flash is added as needed. You can still adjust the flash output +/- to make the fill effect stronger or weaker, as needed.

In M mode the flash is treated as the primary or "full" light souce and ambient light is mostly igrnored (it has to be... it's M as in "Manual" mode, after all). The camera takes the shot based upon providing enough flash to fully illuminate the subject... and it's still automatic so long as you have the flash set to eTTL mode. You can dial the flash +/- as needed to make it stronger or weaker.

Now, even when using flash in M/full, you can make it act as fill. But since the camera is in Manual mode, you have to set up the exposure yourself. If you set the camera to make most or all the exposure with ambient light... guess what, flash will not be very strong because not much additional light is needed. That's essentially "fill", except this time you are controlling it more closely.

Frankly, this is the way all TTL metered flash has to work on all cameras, although I'm sure there are some nuance differences.

Another point to remember with flash used with the camera set manually is that the flash's short duration (about 1/750 second is typical) in effect "becomes your shutter".... The shutter speed you set doesn't really matter, so long as it's the camera's flash sync speed or slower (7D's is 1/250, 5DII is 1/200). You control the strength of the flash... how far it reaches... with your aperture setting.

You mentioned using -2 FEC and still getting blown out images.... You should have stopped down your aperture, but also could have reduced your ISO.

There are also some nuance differences to using flash as fill in Av, Tv or P. There are more explanations at the links referenced above.

Now, I have to say that I really don't know exactly how to set up the built in flash on my 7Ds to operate in either of these modes. I've never used built in flash on the camaeras and likely never will, because built in flashes are pretty useless... Maybe okay for quick use in an emergency when I don't have a much better accessory flash with me, in which case I'd probably just switch to Av.

Built in flashes are weak, use up battery charge rapidly (that I'd rather have available to keep taking shots), recycle slowly , overheat and shut down when used hard for fast shooting situations, often are partially blocked by larger lens hoods and are in the worst possible location for both redeye and ugly shadows. I'll use an accesssory flash, usually on a bracket and connected via an off camera show cord for better shadow effects and to minimize redeye. I really can't recall the last time I used a built in flash on any SLR camera that has one.

Well, if that's how ETTL flash is going to behave while the camera is in M mode, I have to say, that's a really stupid design set up on Canon's part. Whether I'm in M or Av mode, it still means I have to adjust something (FEC or EC respectively) because the camera is certainly not going to figure out the ambient exposure I want in Av (because I ETTR) or it's not going to figure out the fill flash exposure I'm looking for.

I was gettign ghastly "deer-in-the-flash-light" images at 0 FEC and had to adjust to -2 FEC.

Poe wrote in post #12253677
I was gettign ghastly "deer-in-the-flash-light" images at 0 FEC and had to adjust to -2 FEC.

I think you are supposed to get that "deer-in-the-flash-light" look with the pop-up flash. That's the way Canon sells more external flashes.

amfoto1, I'd like to know where I can find the information you provided in the EOS Flash Bible, because from what I have read so far, I can't find anything that describes different flash behavior when the camera is set to Av and M mode.

Just ran a test between Av and M. Took one exposure in Av @ f/5.6 1/60 ISO 3200, switched over to M, put in f/5.6 1/60 ISO 3200, used the same framing, took 2nd exposure. Comparing histograms shows relatively same position of high of peaks & valleys, so it looks like the FE is doing the same thing in Av and M (or at least arriving near the same result). Looks to be about the same when setting the flash metering to average instead of evaluative too.

amfoto1 wrote in post #12252493
In any of the auto exposure modes, the flash acts as "fill".

In the manual mode, flash is treated as "full".

This must be one of the most widespread misunderstanding there is, as far as flash use on Canon EOS cameras go.

E-TTL controls the flash with the ambition to properly illuminate the subject.

That's it.

It doesn't matter which mode you are using, it's doing the same thing. However, depending upon how you set up your camera (the devil is in the details here), the proportion between flash light and ambient can vary. But it's not that easy that the flash acts as fill in certain modes and different in others.

In P mode, for example, the exposure time will never be longer than 1/60 s. Thus, if it's pretty dark, the flash will have to provide the brunt of the exposure, but it also depends upon your ISO setting and the largest aperture your lens supports.

In Tv mode, the camera will try to expose the ambient properly, but if it has opened up to the max aperture, then it will start to underexpose the ambient and thus need more flash power. But when this occurs depends upon the largest aperture and the ISO, and then very much if you have safety shift enabled, in which case it probably doesn't happen at all.

In Av mode, the camera will extend the exposure time as much as needed, which often is enough for all conditions, since the longest time is 30 s. But it still also depends upon which aperture was chosen, which ISO and again, if safety shift is enabled. In this case it also depends upon if you allow it to extend the exposure time beyond a certain limit, a limit which can be set differently on different cameras.

In M mode, it's up to you how you expose the ambient, which in turn will change the ratio between flash and ambient. Something which is concluded further down in the post, revealing that in this case the poster knows how it works, just summarized it to look wrong to begin with.

When the camera is set to expose ambient as it wants to, the ratio between flash and ambient will be about 1:1.