Sony solution for those struggling with TTL flash metering

jyc860923

Veteran
Aug 29, 2018
104
Shenyang, China
贾一川
You might know those things that no reviews ever cover but can really make a camera system undependable for certain types of work, and when you ask, people tell you "that's what manual mode's for", or "that's just the way it is", it shouldn't have to be.

And TTL flash has long been the worst offender for me. In short, a good flash system should not only offer you basic options like sync modes and compensation, but also, more importantly, make output decision based on whether it's fill flash or the main light source, you may call that silly but remember how ugly most auto flash shots often look?

Canon does it right, Olympus not far behind, Panasonic and Fujifilm both fail for reasons I will explain in the end of the post, Nikon never have I used, and Sony I'm writing this solution for.

By default, when using an external flash my a6400 will try to use the flash in fill mode, if you use the on-board flash the problem doesn't exist.

The problem is, Sony doesn't provide me with an option to use the flash as the main light source, it'll always try to metre based on the ambience and it may for example choose ISO 8000 while using very low flash output, which isn't practical because fill flash is usually used NOT in the dark.

THE SOLUTION is to create a few MR settings, MR is a mode on the dial that other brands call C1/C2 which lets you recall your registered settings quickly. The key settings is auto ISO range depending on what you shoot, the power of your flash unit, your lens aperture and personal noise tolerance. For what I do with the flash, my two MR settings are with ISO range set to 100-1600 and 100-100 with the latter exclusively using the flash as the main light source. There are other things you can tweak too, but by default Sony choose 1/60s as the minimum flash shutter speed and AWB, I have my 1st MR preset made in P mode so it'll automatically choose shutter speed and aperture values for flexibility, and the 2nd MR preset made in S mode to enable the fastest available shutter speed of 1/160s and that way I can ensure minimum exposure from ambient light.

My a6400 allows for up to 3 MR settings so that leaves another one for further customisations, like one with ISO range of 100-3200.

For a while I experienced strange results with AWB with flash enabled, turns out I have changed the white balance lock from default to shutter half press, change it back to either of the other two options and it should choose the correct WB for your flash.

Here I'll explain my problems with Panasonic and Fujifilm flash system.

With Panasonic, using external flash will disable auto ISO. Using on-board flash this problem doesn't exist, the latest Panasonic camera I've tested with was the GX85.

With Fujifilm, the only model I've tested with was the X-E3 though I believe other models don't act differently with external flash, it's the same problem as the Sony by default, Fujifilm cameras don't provide the same level of customisation to mitigate the issue.
 

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