The purpose of 2 additional contacts on the flash foot

[chuck]

<p>I just picked up a couple of used SB-800 flashes on ebay. I notice there are two copper electric contacts on the bottom of the flash, under the external power socket and just in front of the standard flash foot. These contacts touch nothing on the camera and I can find no flash accessories which seem to engage these contacts. What are they for? </p>

[pete_s.]

<p>AF assist light when you mount the flash on a Nikon TTL extension cable, SC29 I think.<br>

Just to clarify, the flash powers the AF assist light on the extension cable.</p>

[al_derickson]

<p>I can't remember exactly, but on a camera that is iTTL compatible, one contact is the trigger signal, one is the stop signal, one is the ready signal and one reads lens information.</p>

<p>Al</p>

[rodeo_joe1]

<p>Thanks for that Pete. I too was wondering what those gold-plated horns sticking out of the flash foot were for. I assumed it was some yet-to-be-released feature designed to make us update our flash equipment (again). I'm now happier to know that it's just some obscure feature I'll never use.</p>

<p>In fact who does use off-camera flash when it's so dark the camera can't focus?</p>

[ShunCheung]

<p>Pete's answer is correct. See this thread from 5 years ago: http://www.photo.net/nikon-camera-forum/00WKeH</p>

[chuck]

<p>Does the AF illuminator on the SB-800 itself work if I use a SC-17 cable?</p>

[ShunCheung]

<blockquote>

<p>Does the AF illuminator on the SB-800 itself work if I use a SC-17 cable?</p>

</blockquote>

<p>Yes it does, with either the SC-17 or SB-28.<br>

If you use the SC-29, you can select either the the AF assist LED on the flash itself or the one on the SC-29.</p>

[lex_jenkins]

Works great with the SC-29 cord. I've used it in

the dark a few times at outdoor nighttime wedding

receptions and parties. The AF assist illuminator

helps in tricky situations because my camera body

lacked that feature.