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154 The “Recording” (Camera icon) Menu Settings

And for many years, TTL was the best way to do automatic flash in the
35mm film camera world.
TTL will do an outstanding job of giving you perfectly-exposed pictures in
all situations EXCEPT those where the flash happens to bounce off a mirror
or window in the background. In cases like this, the camera measures the
pre-flash light that is bouncing back off of the mirror, and says, “Whoa!!
That’s WAY too much light coming in! I’d better put out much less light in
order for me to expose this scene correctly!” Therefore, in situations where
you were using a flash and a window or mirror was in the background, the
subject would invariably come out severely underexposed.
This is why ADI (Advanced Distance Integration) was invented. ADI
works exactly like TTL, except it also takes the distance the lens is focused
to into account when calculating the flash exposure. By incorporating the
distance information into the intensity-calculating algorithm, you can have
the best of both worlds – the accuracy of TTL without its Achilles’ heel.
(See examples in Figure 5-20 and Figure 5-21.)

Today ADI works with all Sony lenses; however Minolta lenses made
before the year 2000 that don’t have the “D” designation in their name
aren’t capable of encoding the distance information. Mounting such an
older lens onto the camera will automatically default the flash mode to Pre-
flash TTL.

Usually I have this menu item set to “ADI” because the camera switches to
pre-flash TTL if you ever tried to bounce the flash or take it off the camera
and use it wirelessly.

The A77 II has a third setting for this feature – “Manual Flash”. This does
what you think it does – instead of calculating how much light should be
put out, the pop-up flash just blindly outputs a fixed amount of light (as
determined by the Power Ratio setting, described next). This applies only
to the pop-up flash – in fact, when an accessory flash attached to the
camera this option is greyed out. If you want manual output on your
accessory flash, the controls to do that will be on the flash’s control panel.

Contents of this book Copyright © 2014 Gary L. Friedman. All rights reserved.