OMD video issue

[youtubehd]dtasDLgYKlg[/youtubehd]

Can anyone help me?

A night dive video at Lembeh with OMD, the video appear strange with horizontal scanning movement.

What is that ?

My setting for video is 1920x1080 fine, with a single LED video light.

The raw .mov file play with Olympus viewer 2 appear the same.

Thank you.

Regards

Edmond

A night dive video at Lembeh with OMD, the video appear strange with horizontal scanning movement.

What is that ?

My guess is that this is interference between exposure time and the (adjustable) LED lamp. Especially adjustable lamps are likely to have pulse width modulation (PWM) to adjust the brightness of the lamp. In this case the PWM frequency is in the same range as the exposure time of the camera. You should be able to get rid of the interference either by a) adjusting your lamp to max intensity (continuous light) or b) by lengthening the exposure time of your camera. For both of these, you'll need to adjust the sensitivity or gain of the camera.

Hi r4e,

Thank you very much for your information, will adjust it accordingly to remove the flickering.

Thank you !!

Regards

Edmond

This is one I have never seen before. R4e presents a good explanation..thanks. Always learniing

Steve

What light were you using Edmond?

Yup, shutter speed. From the looks of things, you probably need to set it to 1/50 or 1/60 (or multiples of them) to match the 100 or 120hz of the LED light source. Same for fluorescent lights etc. Cameras can "catch" the flicker, which gives that effect.

I wonder if a 'rolling shutter' filter might fix the issue in the footage. I tend to doubt it but it would be worth the experiment.