Flash Metering

[Almond.Butterscotch]

Originally Posted by inkista

I've been posting about this here for years, but, of course, I'm in the Canon threads. And we have the Canon Flash Confusion FAQ laid out in the EOS flash "bible".

On Canons, Av and Tv mode both assume fill; while P and green-box auto assume flash as the main source of illumination. An automated system has to make some choice about the desired ambient/flash balance. Unsurprising that they went for the ends of the spectrum, as those are the most-used scenarios for shooters whose skill levels are going to have them living in Av vs. P.

After reading up on Inkista's link, I've been playing a bit with my flash (I've been meaning to figure flash out for a long while now, and that helped big time) and I've got a question: Is it possible to find the flash's chosen power output after you've taken a shot in iTTL in camera?

If it makes a difference, I'm shooting with a D40 + SB600.

[Almond.Butterscotch]

Anyone? Bueller?

[candleman]

not that I know of.. I know the SB600 displays the EV it underexposed by ....that's about it.

the only thing i've seen in the exif is "Flash fired, return detected", "Auto" or "TTL"

[OsmosisStudios]

Not that I know of, but I cant imagine why you'd need it.

[Almond.Butterscotch]

Originally Posted by OsmosisStudios

Not that I know of, but I cant imagine why you'd need it.

for the same reason why for about two-three months I looked at the shutter speed of most every photo I took after taking it: to get an idea of what setting a situation requires.

[candleman]

in TTL you can't set your power output anyway so it doesn't matter what the power outputr was... right?
(except in terms of a +or- FEC)

if you really want to know what the flash did, switch to manual and adjust the flash power accordingly until you get the same shot as the TTL.

all you should need to remember is the +or- FEC you dialled in and the amount you underexposed the ambient by, in conjunction with your metering mode and what you metered off of, and weter you used direct flash or bounced....

that's what you should be writing down if you want to learn TTL flash.

[Almond.Butterscotch]

Originally Posted by candleman

in TTL you can't set your power output anyway so it doesn't matter what the power outputr was... right?

In Aperture-Priority, you can't set your shutter speed, but if you can look at the SS, you can start getting an idea about the relationship between the two for various situations when you want to or need to shoot in manual (like with film).

Originally Posted by candleman

all you should need to remember is the +or- FEC you dialled in and the amount you underexposed the ambient by, in conjunction with your metering mode and what you metered off of, and weter you used direct flash or bounced....

*scratches head*

[candleman]

Originally Posted by Almond.Butterscotch

In Aperture-Priority, you can't set your shutter speed, but if you can look at the SS, you can start getting an idea about the relationship between the two for various situations when you want to or need to shoot in manual (like with film).

sure, I see what you're saying but the flash power is different for every situation, there is never a situation where you will put in a manual flash power in TTL is there?

If you put the flash in manual mode it stops metering and does what you tell it....so knowing is irrelevant.

if you are trying to learn how to shoot manually for film, TTL is going to be a waste of time. A flash meter will be a better tool to put to use.
TTL+ a metering mode is a totally different thing to shooting flash manually.

also. flash and shutterspeed only occasionally have an effect on one another with regard to overall exposure... they don't work "together".

[scootermcq]

I could be wrong, but doesn't CS5 show the GN number in the file information tab?