Recently, I had an assistant be my voice controlled lightstand - I had him holding one of my SB-800's and pointing it where I wanted it. My question is can the way he holds it, or where he points it to affect the amount of light that the flash determines to output?
Can his hand cover something that makes the flash put out an incorrect amount of light - over or under expose?
If he aimed the flash just behind and beyond the target, would the flash know and calculate for a different target than what the camera is focused on?
#1. "RE: Question concerning hand-holding flash" In response to Reply # 0
I assume you are using the SB800 in the CLS TTL mode, correct?
If yes, and the VALS (Voice Actuated Light Stand) points it beyond, or behind the subject, the amount of light produced at shutter-open, image capture time will be a function of the reflectivity of the area covered. If the area covered is highly reflective, you will likely get under exposure. If it is very dark and non-reflective, you will likely get overexposure.
If you are using it in CLS Manual mode, will have to select the desired power level manually.
Some things to consider:
1) The small round IR (InfraRed) sensor just ahead of the SB800 battery door must be pointed at the on-camera master/commander speedlight, and the VALS must keep his hand away from it.
2) Daylight and night time shooting sessions will behave differently, as a function of ambient illumination, or lack thereof.
3) If the remote SB800 is used to illuminate a backdrop behind the subject, using manual mode will probably produce more predictable results, following a bit of testing to identify the desired power level.
Tell us a bit more about your configuration and perhaps we can continue.
Hope this helps a bit.
HBB in Phoenix, Arizona Nikonian Team Member
Photography is a journey with no conceivable destination.
#2. "RE: Question concerning hand-holding flash" In response to Reply # 1
Johns Creek, US
I'm using CLS in some situations, and TTL flash triggers in others. CLS is usually without VALS, and uses traditional lightstands. I can control that scenario pretty well. When I am working through an event where I am moving a lot, I found that some photos were overexposed, but I wasn't sure if the guy holding the flash was pointing at the right location, so that's why I was asking. Additionally - I was not in spot metering, and wasn't in single point AF, so it could have been that I made a mistake. Just trying to understand more about how the camera and flash communicate, and how they determine how much light to output.