Mike, did you get this sorted?

Does your video level meter let you test sync level?

If you're putting a monitor directly onto the camera, then a slightly poor sync level may not be apparent, but once the signal goes into processing, the sync becomes more critical. It should be 0.3volt. I have similar probs with DM dvr's when a camera sync drops below 0.27volt. It can be that close!

Just seen this thread for the first time

We used to get this problem with some colour Vantage cameras and it was down to the cameras DD lens controller being cwap.

The solution was to use a AI lens that had the lens control built into the lens.

Hope you got it sorted :

could this be down to setting the camera up in the artificial light of the control room, then actually using it in stronger full day light and so causing the lens auto-iris to close giving a black image?

regs

alan