SB800 master and sb600 remote/slave

Joined: 14 Nov 2005 Posts: 174 Location: Baltimore, MD

I asked this question on photo.net also. Quicker I get an answer the better.

So I was playing around with a 600 tonight to accomidate my sb800. My question is do they compensate for each other in TTL mode? I can use only the SB800 and get a really bright flash but when I use the SB800 with the SB600 and turn the sb600 so its flash will not show up in the picture the SB800 flash comes out underexposed in the picture. I was able to get them both to fire with a well exsposed picture when aiming at the same subject. That is what makes me think they compensate for each other in TTL mode. I guess it is best to use manual settings on both flashes when using them together. Hopefully someone can make sense out of what im trying to say.

Joined: 18 Nov 2006 Posts: 288

TTL flash metering measures the amount of light hitting the sensor and then turns off the flash units when enough light has arrived. The source of the light is fairly immaterial. The ability to turn off the flash units is the issue and that's why you need compatible flash units. It doesn't matter how many flash units you use or how much light emanates from each. When enough light has reached the sensor, the TTL system will shut off the light. Simple as that.