Wandering light/exposure??
 

A colleague shot this today and when reviewed the footage I notice that the colour is changing all the time, watch the back wall carefully and you will see.

He had the camera on manual, manual zoom and did a white balance before shooting. He did not have my lights setup as the office was too small, is this the problem? Is the camera struggling with the light? He knows the overall picture is dark so he is going back to re-shoot this interview but the concern is that the cam seems to be shifting colours on it's own?

Here is the footage (40 seconds long)

http://www.aopy22.dsl.pipex.com/test.wmv

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posted on Alan Roughly still waiting for approval to get on DV forum.

Alan,
Sorry but i dont have media player so i cant view your file but you might wanna check out this thread that i started a little while back when i was struggling to figure out why the whites in my background kept changing color when shooting in a studio with flourescent lights... http://www.dvinfo.net/conf/showthread.php?s=&threadid=22182

hope it helps

What you describe sounds like an effect seen with common flourescent lighting (and other discharge type lighting), especially if the shutter speed is above 1/60. And the reference to a dark image sounds like a fast shuttter setting was used. Try use a 1/60 shutter, or change to incandescent lighting.

Alan,
Do you know what shutter speed was used? It should have been 1/50th for use with florries in the UK. Any non-multiple of 1/50 could easily give a gradual colour-phasing as well as exposure shift, due to the shutter only allowing the ccd's to see a varying phase of the light from the tubes' discharge.
(Nice to hear a Welsh accent from the subject...)

Robin.

Thanks guys, you have confirmed exactly what I was thinking (honest!)

Since found out that 1/150th was used as the shutter speed (PAL), 1/50th being my preset always as I have come a cropper before. The safe answer is if light is not there "get some" rather than forcing the camera to find it using the shutter speed.

Learn as we move on I suppose, Alan just said he will always use his lights in future inside buildings.

If the shutter speed was 1/150th, he would have been losing the availability of just over a stop in exposure.

Robin

Robin, we must have posted at the same time (ish) last time.

Like I said I only found out about the shutter speed this evening, I never vere from 1/50th now as I ruined a 2 hr shoot when I first started as I noticed by changing the ss you can up the light. It was only when I reviewed that I noticed problems so I stick to 1/50th and move the subject or get lights to get it right. Easy to say in hindsight.

Alan (my colleague) in this case did the opposite as you said with the ss which is weird in itself. We can all learn ;-) I certainly do.