jmwilder
03-23-2005, 10:55 AM
Hi. First post. Thanks for the great resource.
I just got my SB-800 in the mail and set to work taking pictures of fish. I set the SB-800 and D70 up for commander mode per Jay Luto's posted instructions. I then set the SB-800 on top of the tank with its diffuser dome in place. In aperture-priority mode with matrix-metering, I took a few photographs at f/11. The SB-800 fired as anticipated, but the subject was overexposed. This was fixed easily enough by stopping down the lens. But I don't understand why I had this problem in the first place. As I understand TTL, at least with the flash attached to the camera, the D70 calculates exposure based on preflashes and then directs the SB-800 to produce the necessary flash to yield the correct exposure. This frees up aperture to control depth of field and, together with shutter speed, background exposure based on ambient light. Put differently, the subject ought to be exposed correctly irrespective of my choice of aperture (in aperture-priority mode).
Any clarifications on this or suggestions as to how best to use the SB-800 in commander mode would be greatly appreciated.
One caveat: I was taking pictures of a small fish that came nowhere close to filling the frame. I'm thinking the matrix metering might have been trying to set the correct exposure for the dark rock in the background. I didn't have time to experiment much, but spot metering seemed to be more effective. Is matrix or spot metering generally preferred in this context? Thanks.
I just got my SB-800 in the mail and set to work taking pictures of fish. I set the SB-800 and D70 up for commander mode per Jay Luto's posted instructions. I then set the SB-800 on top of the tank with its diffuser dome in place. In aperture-priority mode with matrix-metering, I took a few photographs at f/11. The SB-800 fired as anticipated, but the subject was overexposed. This was fixed easily enough by stopping down the lens. But I don't understand why I had this problem in the first place. As I understand TTL, at least with the flash attached to the camera, the D70 calculates exposure based on preflashes and then directs the SB-800 to produce the necessary flash to yield the correct exposure. This frees up aperture to control depth of field and, together with shutter speed, background exposure based on ambient light. Put differently, the subject ought to be exposed correctly irrespective of my choice of aperture (in aperture-priority mode).
Any clarifications on this or suggestions as to how best to use the SB-800 in commander mode would be greatly appreciated.
One caveat: I was taking pictures of a small fish that came nowhere close to filling the frame. I'm thinking the matrix metering might have been trying to set the correct exposure for the dark rock in the background. I didn't have time to experiment much, but spot metering seemed to be more effective. Is matrix or spot metering generally preferred in this context? Thanks.