Gain to 0
 

Hi Andrew. Yep, it's set to 0, as I don't like the noise that comes from using gain.

I was thinking... is it an exposure meter in the top left of the screen that shows itself in manual, and if so, can this affect any of the fixed setting in this mode?

Xl1s On manual exposure
 

C J,

I was thinking the same as Jeff. If you are running off of the AC adaptor, any brief voltage sags from someone switching on a heavy load somewhere, could cause this.

As Jeff said, try running on battery power and see if the problem still shows up. The key to this is that you mentioned the brightness 'dips' momentarily which would suggest a brief loss of voltage to the camera. Had you stated you were getting intermittent 'brightness up' events, I would be more suspect of the camera.

Anyway, the battery vs. ac adaptor test will hopefully yield an answerr. Even if you see no difference, don't rule out this possibility because it could have been something that was occuring on that day only (ie construction, a coffee pot heating element cycling on/off, etc.)

If you do see the problem using the ac adaptor, look for anything on the same circuit that would initially draw a heavy current load such as a motor or high wattage light bulb.

Hope this helps.