AA flash mode

Recently I read that wedding photographer Susan Stripling uses her SB800/900 in AA mode when using it on camera

rather than TTL because it gives more consistent exposures.

I've only used TTL and TTL-BL modes. TTL-BL works well (but then there is a lot of leeway for fill flash) but TTL

is inconsistent, sometimes I've switched to TTL-BL and increased the flash compensation when TTL is screwing up

because it can give better results since it takes distance into account while TTL easily gets fooled by anything

near the camera.

Does anyone use AA mode? How does it work and is it worth trying?

<p>AA mode is comparable to older auto thyristor flash with optical sensors on the flash unit itself. Getting inconsistent results with TTL compared with AA indicates something else is wrong. I've used both fairly extensively, switching the SB-800 between my D2H in TTL mode and FM2N and F3HP in AA mode. On my non-TTL film cameras the results in AA mode were very good, equal to any auto thyristor flash and better than most. And I've compared the SB-800 on the D2H in AA and TTL modes. AA is very good, but TTL is more consistent. Nikon's FV Lock option with TTL flash is what sets it apart from most other TTL flash systems and gives it a huge advantage over AA.</p>

<p>In TTL mode the system is basing the exposure on light measured in the camera. In AA mode an optical sensor on the flash body itself measures the light, just like countless auto thyristor units dating back decades. Flash unit-based optical sensors are notoriously easy to fool in tricky situations. For example, light reflected from the exterior of an oversized flash modifier or diffuser, such as those popular tupperware doodads, can easily fool the optical sensors on flash units. But the TTL flash will read only the light reflected off the subject, so it's not easily fooled. Block the optical sensor on the flash with a thumb, a bit of tape or an aftermarket flash modifier drooping over the sensor window. See what happens.</p>

<p>TTL-BL is best reserved for outdoors in daylight. It won't deliver as consistently reliable results indoors or in low light as will TTL mode. I've compared both many times indoors and unless the interior is illuminated by lots of bright sunlight TTL-BL doesn't deliver the same shot to shot consistency.</p>

<p>Try it yourself, compare TTL, TTL-BL and AA. Be sure to include strongly backlit scenes, high contrast subjects comparable to a bride in a white gown and groom in black tux, subjects standing against a featureless black or white background, or even a highly reflective background with a window, mirror or tile/marble wall behind the subjects (some of which are unavoidable in some types of candid photography). TTL, especially combined with FV Lock, will reliably deliver more shot to shot consistency than AA.</p>

<p> Related subject...<br>

<a href="../nikon-camera-forum/00WelS">http://www.photo.net/nikon-camera-forum/00WelS</a></p>

<p> </p>

<p>BTW, I should clarify that when I use the SB-800 in auto mode on the FM2N and F3 it's in "A" mode, not "AA". Otherwise, the same basic limitations apply - in these modes the flash relies on an optical sensor on a lower front corner of the SB-800, rather than TTL.</p>

<p>And I don't mean to imply that AA or A flash isn't useful. The SB-800 has provided much better results in that mode with my FM2N and F3HP than any other auto thyristor flash I've used, including older Nikon non-TTL auto flashes. It's pretty remarkable. I got consistently accurate exposures of an indoor candlelight event in an otherwise darkened huge auditorium a few years ago using the SB-800 in A mode on a bracket on my FM2N. Most auto thyristor flash units will choke under such extreme conditions.</p>