Back Button focus and E-TTL

CliveyBoy wrote in post #16810629
This is from my YN622C Guide, but is about Canon implementations:

Flash Exposure Lock (FEL)
• The camera must be in a creative mode.
• Live View mode must be disabled.
• Flash mode must be E-TTL.
• First focus on subject.
• Then press the camera’s

or [FEL] button.
• Flash metering temporarily changes to Spot metering. The ambient and flash exposures are locked into the camera for 16 seconds, or while [½-shutter] remains pressed.
• “FEL” appears momentarily, and the < Flash> icon and “*” are lit in the viewfinder. The values are discarded when the shot is taken, or a hi-speed burst ends.
• If the subject is too far away and underexposure will result, the < Flash > icon will blink in the viewfinder. Move closer to the subject and try the FE lock again.

Question - does the FEL symbol appear in the viewfinder?

Hmm... I just tried it with 3 flashes (Several shots each) and only saw the FEL indicator twice, and then only for a second before it went off, never did see a pre-flash (or couldn't pick it out when the flash fired). Tried aiming towards a light source, a dark area and a mixed lighting area, didn't seem to matter.

Perplexing!

I may just say the hell with it and go back to manual... this is more work than I bargained for, what with this supposedly being a time saving solution...

CliveyBoy wrote in post #16810629
This is from my YN622C Guide, but is about Canon implementations:

Flash Exposure Lock (FEL)
• The camera must be in a creative mode.
• Live View mode must be disabled.
• Flash mode must be E-TTL.
• First focus on subject.
• Then press the camera’s

or [FEL] button.
• Flash metering temporarily changes to Spot metering. The ambient and flash exposures are locked into the camera for 16 seconds, or while [½-shutter] remains pressed.
• “FEL” appears momentarily, and the < Flash> icon and “*” are lit in the viewfinder. The values are discarded when the shot is taken, or a hi-speed burst ends.
• If the subject is too far away and underexposure will result, the < Flash > icon will blink in the viewfinder. Move closer to the subject and try the FE lock again.

Question - does the FEL symbol appear in the viewfinder?

Very good find.

Vetteography wrote in post #16810718
Hmm... I just tried it with 3 flashes (Several shots each) and only saw the FEL indicator twice, and then only for a second before it went off, never did see a pre-flash (or couldn't pick it out when the flash fired). Tried aiming towards a light source, a dark area and a mixed lighting area, didn't seem to matter.

Perplexing!

I may just say the hell with it and go back to manual... this is more work than I bargained for, what with this supposedly being a time saving solution...

Have you tried ETTL without FEL? I ask because I have honestly never used FEL, not once. I've never had any major issues using ETTL flash with manual camera settings, so I'm looking at your thread kinda befuddled.

Vetteography wrote in post #16807402
t turns out that if you are like me and have switched to back button focusing, you sometimes focus and take your thumb off the button before shooting. Did you know that you are causing the E-TTL system to go into evaluative mode instead of metering at the focus point?

Well... now you do. I thought I would share in case there are others like me who are trying to learn.

This page explains it very nicely: http://www.dlcphotogra​phy.net/ETTL/ETTL.htm

Without even bothering to read the link, I can tell you that only the 1D bodies will spotmeter using the AF selection point, no other models from Canon will use AF point to spotmeter!

Second, no Canon bodies use 'flash spotmeter'. Period. Flash metering is only in 'evaluative' or in 'average' mode...no spotmeter of any type for flash.

Third, the only deviation to point 2 is when you use Flash Exposure Lock...then it uses only the AF in the center of the viewfinder, never any other AF point!

Having told you those three truths, I will now go read the links to find what fallacies it is spreading!

Wilt wrote in post #16816156
Third, the only deviation to point 2 is when you use Flash Exposure Lock...then it uses only the AF in the center of the viewfinder, never any other AF point!

I thought it was the area within the spot meter circle.

Scatterbrained wrote in post #16810793
Have you tried ETTL without FEL? I ask because I have honestly never used FEL, not once. I've never had any major issues using ETTL flash with manual camera settings, so I'm looking at your thread kinda befuddled.

I tried it but did not like it. I always had to tell people the first flash was not the actual picture being taken.

The manual states to press the M-Fn button and take the picture. It does not state whether to hold it but it would be difficult to do that and use the shutter button.

When I did try it I programmed the custom controls so the AE lock was the FEL button. I always pressed and released before taking the next the shot. I never tried holding it to see if it maintained spot metering. If it did that might prevent using the pre fire repeatedly but I doubt it.

Wilt wrote in post #16816156
Without even bothering to read the link, I can tell you that only the 1D bodies will spotmeter using the AF selection point, no other models from Canon will use AF point to spotmeter!

Second, no Canon bodies use 'flash spotmeter'. Period. Flash metering is only in 'evaluative' or in 'average' mode...no spotmeter of any type for flash.

Third, the only deviation to point 2 is when you use Flash Exposure Lock...then it uses only the AF in the center of the viewfinder, never any other AF point!

Having told you those three truths, I will now go read the links to find what fallacies it is spreading!

This is correct. The FEL is like spot metering the center of the frame for flash exposure. Otherwise you choose average or evaluative in the menu system.

digital paradise wrote in post #16816221
I tried it but did not like it. I always had to tell people the first flash was not the actual picture being taken.

The manual states to press the M-Fn button and take the picture. It does not state whether to hold it but it would be difficult to do that and use the shutter button.

When I did try it I programmed the custom controls so the AE lock was the FEL button. I always pressed and released before taking the next the shot. I never tried holding it to see if it maintained spot metering. If it did that might prevent using the pre fire repeatedly but I doubt it.

You do not need to hold the m-fn. Just tap it for FEL.

Yes that was what I was doing. But you have to tap it before each exposure. I just wondered if you keep it pressed it remembers the previous exposure but I doubt it. I have never seen that in the manual.

You can keep FEL as long as you like. There's a separate little * icon close to the flash icon in the viewfinder. As long as that little * is on, the last value from FEL is remembered. If you take pictures and don't let go of the half-press of the trigger button in between, the FEL value will be remembered.
On a 1DX, for example, you can also set the timeout for this state as you like, but you can't do that on non-1D cameras.

So there's indeed spot metering for flash, when using FEL, in spite of what Wilt wrote above.

I was in pretty steep learning curve at the time so I only tried it for a short time. Since I tend to have the shutter half pressed most of the time it was probably there and I did not notice. I pressed the FEL every time before each exposure. This was mostly in a reception type situation so I 'm not sure how accurate keeping the exposure locked would have worked. Thanks for the info.

Seems to me a button that you press and it spring locks while firing the FEL pre exposure would be better. You don't need to hold any button. If you press it again it unlocks and it goes back into evaluative mode. I'm pretty good with the shutter button half pressed because that is my preferred method when in AI Servo when birding, etc but I can't see myself using the FEL again any time soon. Not sure I'd like trying to keep pressed and making sure the * is illuminated when I'm busy. The finger does come off the shutter when I'm moving around.

If that's what you need you are probably better off using the flash in manual power mode.

apersson850 wrote in post #16817959
If that's what you need you are probably better off using the flash in manual power mode.

That is where I am right now. Screw it... manual works for me just fine.

apersson850 wrote in post #16817959
If that's what you need you are probably better off using the flash in manual power mode.

ETTL works well for me in a busy environment. Manual when I have time to set up.

digital paradise wrote in post #16816175
I thought it was the area within the spot meter circle.

I was not referring to the AREA of the spot, but merely the LOCATION of the metered spot