Use of P mode with E-TTL unpredictable?

When trying my Nissin Di466 flash and 20D indoors, I get strange things happening in program (P) mode. Sometimes it behaves more like Av mode and sometimes like M mode. Also, it sometimes ignores the flash altogether when trying to use bounce flash.

As it's so unpredictable, I think I should avoid using P with flash. Av and M seem perfectly OK, i.e. they do what they're supposed to do. Any views on this please?

Here is my view:

ALWAYS use M mode with flash. All those other modes are for auto exposure of ambient light. With flash photography you do not want auto exposure of ambient light because THERE IS NO AMBIENT LIGHT! That is why you are using the flash in the first place!

The only exception to this is outside daylight fill flash. But even there I would use Manual and use the exposure meter to slightly under expose the scene and let the flash fill in the rest automatically. Then use FEC to fine tune your results.

With M you have full control of how much of that ambient light you might want to take advantage of.

Oh, in many cases when I use a flash, there's plenty of ambient light too. That's why I'm using the flash, to do something about the shadows.

This happens both out- and indoors, but perhaps more often outdoors. This is one example of an image, which would have looked dull if there was not some flash light added.

P mode is unpredictable only if you don't pay attention to the dashboard in the viewfinder. There you can see which shutter speed and aperture it will select. Since P mode never goes slower than 1/60 s, it's "unpredictable" in such a way that when you pass the limit where the ambient can't be properly represented with 1/60 s, the background will start getting darker. When it gets brighter, it will close down the aperture, and only the aperture when passing the shortest sync speed, often 1/250 s.
But all this is how it works, so in a way it's just as predictable.

Apart from this, I agree that using M with flash is often easier than an automatic mode, in spite of how it sounds.

msowsun wrote in post #12014844
Here is my view:

ALWAYS use M mode with flash. All those other modes are for auto exposure of ambient light. With flash photography you do not want auto exposure of ambient light because THERE IS NO AMBIENT LIGHT! That is why you are using the flash in the first place!

The only exception to this is outside daylight fill flash. But even there I would use Manual and use the exposure meter to slightly under expose the scene and let the flash fill in the rest automatically. Then use FEC to fine tune your results.

With M you have full control of how much of that ambient light you might want to take advantage of.

+1 ^^

I have to agree with Mike as the simplistic guide below has never failed me and any newbie to flash photography using this method will be taking keeper shots coupled with vertical bounce & a flash card pronto:

---------------
Indoors always shoot with your camera in "Manual Mode" when the external flash is attached. For starters simply set your camera parameters at f5.6, 1\100, ISO400, and your external flash to ETTL Evaluative mode. Take a test shot and then you can adjust the FEC + or - to your tastes on your foreground subject. The in camera settings above is a starting point for the background ambient lighting which you can also re-adjust dependent on the existing ambient light. The FEC + or - is simply exposing the right amount of light on your foreground subject.

Here is a link for folks to read that should help:

http://photonotes.org …les/eos-flash/index2.html

Personally when i shoot outdoors in late afternoon light i always use AV mode, which with the external flash attached creates fill flash.

---------------

Regards,

msowsun wrote in post #12014844
Here is my view:

ALWAYS use M mode with flash. All those other modes are for auto exposure of ambient light. With flash photography you do not want auto exposure of ambient light because THERE IS NO AMBIENT LIGHT! That is why you are using the flash in the first place!

The only exception to this is outside daylight fill flash. But even there I would use Manual and use the exposure meter to slightly under expose the scene and let the flash fill in the rest automatically. Then use FEC to fine tune your results.

With M you have full control of how much of that ambient light you might want to take advantage of.

Yes I guess there is always 2 sides of the story

I don't see flash as a replacement for ambient light, but rather, a supplement.

Consequently, I use AV mode with flash almost 90% of the time.

There are times when I use M mode though (about 10% of the time) - that's when I am in an ultra fast paced situation (e.g. a cake cut) where there is no time to retake the shot if the ambient exposure is off causing shutter drag. In those situations I will carefully meter the scene prior to the action happening, and use M to lock in my settings

Any other time - AV with flash

Silverfox1 wrote in post #12016127
+1 ^^

I have to agree with Mike as the simplistic guide below has never failed me and any newbie to flash photography using this method will be taking keeper shots coupled with vertical bounce & a flash card pronto:

---------------
Indoors always shoot with your camera in "Manual Mode" when the external flash is attached. For starters simply set your camera parameters at f5.6, 1\100, ISO400, and your external flash to ETTL Evaluative mode. Take a test shot and then you can adjust the FEC + or - to your tastes on your foreground subject. The in camera settings above is a starting point for the background ambient lighting which you can also re-adjust dependent on the existing ambient light. The FEC + or - is simply exposing the right amount of light on your foreground subject.

I don't agree with the baseline settings recommended due to my personal shooting style - the above baseline figures are of the school of thought that flash is supposed to replace ambient. For indoor environments, I find I am typically at ISO 1600, 1/50 or so, even with fast primes at f/1.2 or f/1.4

Although my conditions may be darker than most, the reason is I want to expose the ambient properly, and use flash as fill, even indoors.

Oh don't use P - P stands for "Poor"

smorter wrote in post #12016176
I don't agree with the baseline settings recommended due to my personal shooting style - the above baseline figures are of the school of thought that flash is supposed to replace ambient. For indoor environments, I find I am typically at ISO 1600, 1/50 or so, even with fast primes at f/1.2 or f/1.4

Although my conditions may be darker than most, the reason is I want to expose the ambient properly, and use flash as fill, even indoors.

I merely mentioned a Starter point for the settings.

Also most folks dont have the luxury of using a nice body like the 5D MKII or 1D III that handle ISO1600 with minimal noise like you have !

Fair enough point

I started with the 400D (XTi) and 40D though, and I also used them at ISO 1600. I think modern cameras in the same class like the 550D and 60D are better than those cameras, so they should be able to handle it fine

smorter wrote in post #12016179
Oh don't use P - P stands for "Poor"

If you know how it works it can be "Perfect".

Thanks for the very helpful replies. I conclude that P mode, even if it does follow defined rules, is just not worth bothering with for flash. I should add that I can't see any use for Tv with flash either.

I'll stick to M mostly, with flash, and Av whenever I need fill flash.