Flicker or Shimmer
 

Hi, I'm a newcomer to using digital video cameras and obviously have, and will have from time to time, many questions relating to video filming. Having got my new NV-GS100K up and working I noticed than on playback (on various newish TVs) there was quite a a bit of 'flicker' or 'shimmer' or 'waves' in some situations where there was a major difference in contrast or brightness. This also seems to occur more when panning (even very slowly). I had filmed on auto (default) setting, fairly early in the morning so the contrast and brightness may have been a problem. The colors also seemed particulary sharp. Similar effects occurred
when filming indoors. Any ideas on how to overcome this problem?

Thanks

Paul

In "auto," the sensors (or eyes) are deciding what to focus and what to white balance.

Thanks for that. Someone with a little more knowledge than me has had a look at the video I shot and described the phenomen as "zebra" which is particulary noticeable in 'white' areas.

Ooops, "zebra" is a feature to inform the camera user that there is over-exposure (overload of the CCD input) and the signal is clipped.

Zebra is only on the viewing screen (LCD or EVF) and can be turned on or off. Certainly not recorded in the tape.

Paul, some areas in Japan (Tokyo and eastern areas) have 50Hz mains and NTSC framerates. High brightness zones on TV are known to show area flicker at these refresh rates. Also interline flicker and line crawl are some artifacts which are well known with CRT displays. Look for a 100Hz TV if this is yr problen

Thanks Andre. I'll look into that too. I noticed yesterday afternoon when I tried some further shooting (still in auto mode) that the distortions could also be seen through both the camera viewfinder and on the LED before shooting, which makes me wonder if it's a problem specific to that particular camera.

Regards,

Paul

Why not go to a local shop and see if you can duplicate your concerns with a display model or 2, to determine what your next step will be. Please post your findings here.

Hi Frank,

Yes that will be my next step. I'll do that this weekend and post my findings.

Thanks,

Paul

Paul, if you only get this problem in auto mode and not in (well exposed) manual mode it could turn out that there is an hunting phenomenon in the camera's auto exposure system. Also, if you look at a (VHS) copied version. the VCR video autogain controls tend to show this effect when the applied signal levels are too high or with a sudden change in the average picture level

Well, I took the camera back to the store on the weekend, and the staff agreed that the camera was somewhat faulty and have replaced it. They did say that some shimmer, zebra effect, etc under certain light conditions is fairly common on digital video cameras, but that being experienced on mine was excessive. So, the next step is to try this new one out extensively over the next weekend. Hopefully I won't be disappointed! Thanks for your help everyone.

Paul, way to go. Let us know how this new one works for you. :)