I have had a D700 for several years that I bought to use with my AI-S lenses. I was using it with a Nikkor Micro 55mm 3.5f on a copy stand for the first time to shoot some fountain pens. Not paying attention, I had the camera in Manual mode rather than Aperature Priority like I thought.
The exposures were not coming out the way I wanted. Everything being upside down, I got confused about what I was doing and began holding the AF-ON button down (thinking it was the Exposure Control button) and rotating the main command dial.
This was changing the exposure but not in a way that made sense in what I was seeing in the viewfiender.
Fairly quickly I realized what I was doing wrong, set the camera to A and started using the exposure control, and got good photos.
I would just like to know what the camera was changing with the AF-ON button and Main Command Dial. I can't find anything in the manual.