The above image was taken with a D90, pop-up flash as commander, and a SB-900 held out at camera left. I think that there is something wrong with these photos, but the subjects liked them. My issue? There was too much flash, especially from the front, and there is a shadow at the bottom of the image. But why?
I was certain that I read somewhere, saw a video, or a podcast that said that the D90’s pop up flash, when acting as a commander could not contribute light to the scene. I was wrong.
At home, I had previously been trying to use a two light setup with one light on camera, and another off to the left in an umbrella. Both were SB900’s. I had been playing with the lighting ratios, and what the light looked like. I would leave the umbrella at full power, then decrease the on camera. Then I would lower the umbrella, and increase the light from the on camera flash. This was all done via CLS.
Then I was shooting some informal portraits at a wedding. We were at a country club, on a golf course, and the sun was going down. Twilight blue sky. I set my subjects up with the golf course and the mountains behind them. I held a SB900 with dome difuser on in my left hand at arms length. (I didn’t have other diffusion materials with me.) I popped up my on board flash to use as the commander. It didn’t register that it was set to TTL. I took my picture with a Nikon 17-55 f/2.8 lens on the front, and a shadow shows up in front of their feet! Whoa! Where is the light coming from? I was a little confused and didn’t have time to figure it out, so I just zoomed in a bit more so the shadow wouldn’t be as noticible. I also added some dodging in post to even out the light a little bit.
It wasn’t until I was back home looking at my pictures that I figured it out. The light from the built-in flash was contributing to the exposure. I know that in the past I have sworn at Joe McNally because it seemed like my flash was contributing to the light, when I know that he has said over and over that when using CLS, the commander flash doesn’t contribute light to the exposure. Except when you don’t pay attention.
So, if you do not want your pop up flash to contribute to the exposure, make sure that beside the line labeled Built-In, in the left column it says “–“. If you do want some light from this flash, set it to “TTL”. You will most likely want to lower the light from this flash so it acts as just a bit of fill, by setting the right column to -2 or even -3.
I think my mistake (probably more than once) was when I looked at the menu and saw TTL, and thought, of course that is what I want. But, you probably only want light from the off camera lights set to TTL, and the pop up set to “–” for commander. The most I can hope for is that I have learned my lesson.





I took a SD card (4gig Sandisk Extreme III SDHC) out of my computer, and back into my camera, and I instead of a shot count in the LCD on the top of the camera, I got the letters CHA. What the? I headed to google, and “d90 CHA” brought back a ton of hits. This was not some weird isolated incident. Most were saying it had something to do with the memory card, and that if formated in camera, it would correct it’s self. Since I always format every time I put the card back in, that’s what I tried to do. I usually use the shortcut buttons, but they didn’t work. I then went to the menu, and it the camera seemed to take a long time to format. When it was finished, I still had CHA in the LCD. I took the card out, put it back in, and now the shot count said there were 27 pictures left. Weird. I tried the format again through the menu, and this time it only took a second, and appeared to work. We’ll see how this card holds up. I should mark it so I know which one it is.