Actually, on the 100A, black balance is set by holding in the white balance button after the WB is set. The manual states that this is necessary only the first time you use the camera.
After that, only when you encounter extremely weird mixed lighting that you feel might needs a re-balance.
One of the great things about the 100/100A are the external, easy to access controls such as WB, gain swithes, etc. ; rather than menu based settings for these.
Hope this helps,
Ken
You do not need to use a white card. The camera will automatically stop down the iris closed and then perform the black balance. I usually do a black balance every couple of months. It doesn't hurt the camera, but it makes sure your blacks are set correctly. If you notice any color in your blacks, that is a sign it is time to black balance.
That really doesn't make any sense to me. If it automatically stops down to do a black balance, why even have a black balance? Can't you set up the camcorder such that it does a black balance during startup?
Shouldn't there be a more reasonable answer to this?
The camera needs to adjust the blacks the same way it adjust whites when you white balance. The reason it stops down the lens is so it has a black source to reference. It is not something that has to be done all the time, but most shooters I know black balance at the start of the day of shooting. The DVX manual lists other conditions when it should be black balanced. It is not done on camera start up for the same reason white balance is not done at startup. Things can change over the course of the day. It is not likely that the black balance will shift, but it would be a pain to restart the camera every time to correct it. This feature is on every pro camera made. It is actually a great feature to have on a camera of this price.