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).
Nikon D70 sync speed tests
How Sync Speed Multiplies Flash Power