Night Time Quality Loss

Hi People,

Please excuse me if this was discussed before or if this is right place to ask about this, I work all day, so I don't really have a lot of time to spend reading through the forums.

I am having a little issue, I have recently used FRAPS to record some clips from my FSX which I am trying to create a video with, so the problem is the following.

When I record FSX during night Time (FSX Time), the clips look great (Just like FSX), BUT, when I render the video (I am a beginer so I use the Windows Movie Maker) the quality decreases quite a lot, I have noticed the problem occurs only if the video is recorded during night time, if the video is in daytime with a lot of light, the problem does not occur, even at night time in the flightdeck with the lights on, it looks great; only when there is darkness the quality drecreases just too much.

The video clips recorded look great I repeat (no mater the amount of light).

Is there anything I can do to avoid this?

Why does it happen?

Has anybody had this problem? was he/she able to resolve it?

Could the video editor I use be the problem? if so, What video editor would you recommed? (Remember I am a beginer, not yet a Pro)

Thank you very much for any help you guys can give me.

Best regards from Colombia South America.