TTL Flash + Auto ISO - Solution

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dancook

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Dan
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So what I want is a on-camera flash setup that balances flash with the ambient to an acceptable level, both indoors and outdoors - without having to think about changing settings.

I also want to be able to change the aperture for when F2.8 provides too small a depth of field, but I don't want to have to juggle the other settings.

My initial instinct was aperture priority mode with min SS and auto-ISO, so I did this... and it did not work.

With Auto ISO it defaults to
1) ISO 100, 1/250th, High Power Flash

So out of curiosity I fixed the ISO to 100
2) 1/8th, Low Power Flash

So I messed around with manual mode.

1/125th, F2.8, Auto ISO (max 3200) EV -1
TTL Flash +0.7

Indoors/Outdoors working like a boss!

So in summary

I found in aperture priority mode with auto-ISO, it favours dropping the ISO down to 100 and firing flash on a high setting.

But if I put it in manual mode with auto-ISO, it favours metering the ambient first and applies flash to taste - lovely.
 
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There is a menu setting for EV compensation, I changed it from Ambient&Flash to just Ambient and tried it in aperture priority mode and it seemed ok - but put it back and still seems ok...

The kind of lines up with my experience last week at an event where I setup the flash ready, and my first shots it fired at full flash, way overexposed. Just inconsistency!
 
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I don’t know how the Sony system works, but I don’t trust Canon with all this work.

That said, I don’t do a lot of outdoor fill flash.

My methods

Outdoor fill flash, Auto ISO, AV mode, ETTL flash -FEC

Outdoor key flash, fixed ISO, M mode, ETTL or M flash FEC/M to balance to taste

Indoor dynamic key flash, fixed ISO, M mode, ETTL flash FEC/M to balance to taste

Indoor static key flash, fixed ISO, M mode, M flash M/M to balance to taste

The problem with trying to use auto is that the camera doesn’t know whether I want the flash as fill or key, and what balance I want between key and fill. And as the camera will never be able to read my mind, I can’t see my method changing.
 
dancook said:
I found in aperture priority mode with auto-ISO, it favours dropping the ISO down to 100 and firing flash on a high setting.
Click to expand...
With Nikon this behavior depends on the metering mode... if the metering is set to spot then it uses the flash as primary (low ISO/high power), but if set to one of the others it works in BL mode (balanced light) I prefer matrix metering for this. There's also usually other settings which affect the behavior such as auto FP, max ISO w/ flash, etc.

It's great for run-and-gun, but IME manual works just as well/easily. You can usually set the camera exposure for the ambient and ignore it for quite a while...

My experience with Sony is that they tend to behave more like Canon in most aspects... this would be an aspect I'm not that familiar with.
 
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