Saturday, February 5, 2011

Converting TTL Flash to Manual (Basic)


I got a Nikon SB-600 as my new second flash.  Most of the time I plan to use the SB-600 as a remote flash (triggered via CLS).  For on-camera bounce flash, I plan to use my primary flash, the SB-800 simply because it's more powerful.  There is one type of situation, however, when I do plan to use the SB-600 on-camera -- and that's to take advantage of the D70's unlimited sync speed.

So far, the easiest way I've found to use the unlimited sync speed in combination with off-camera flash is to have a manual flash attached on-camera to the D70.  The manual flash can trigger the SB-800 optically (in SU-4 mode) even at 1/8000.  Unfortunately, simply switching the SB-800 or SB-600 to manual won't work -- the D70 would still know that there's a flash attached, and will be limited to its normal sync speed of 1/500.

To fool the D70 into thinking there's no flash, you can mount an all-manual flash (such as the YN-560). Or you can tape over the TTL contacts of a TTL flash.  That's what I did to the SB-600 (I taped the two pins below the middle pin).

Once setup this way, I can use the SB-600 in manual mode on the D70 without the D70 knowing that there's a flash onboard.  I can shoot all the way to 1/8000 and be able to trigger the SB-800 optically.  That's what I was able to do in the test shot above. 

In that shot, there were two light sources: the SB-600 on-camera, in manual mode, bounced to the ceiling/wall at 1/2 power.  I used the SB-800 in SU-4 mode to fire against a wall behind a TV at 1/128 power to provide the accent light on the mannequin's cheek (the TV acted as a flag to avoid lens flare).

RELATED POSTS:
Nikon D70 sync speed tests
How Sync Speed Multiplies Flash Power