I don't want to waste your time. I am not a cinematographer, I'm a writer/director but the last two years I'm trying really hard to learn about camera and lights. I'm currently shooting a short film just for experimenting with my camera (a Sony EX1).
It was supposed that the film takes place during nighttime, which means that I shoot on low-light conditions. The problem is that I get unbelievable amounts of gain (or grain, or pixels, I don't know how they're called).
Theoretically, when you shoot with gain -3db, you were not meant to have those pixels. I know that since you choose another option (let's say 9db) the image should be brighter, because there are signals which are being boosted electronically, but you have also the pixels. Why do I still get pixels since I shoot on -3db? It was supposed to be dark images (cause the camera can't see), but dark not grainy. How can I have black dark images without gain? I mean why black cannot be black and it has millions grey pixels jumping around my frame?
It seems to me that you must have switched the camera to 'auto' without realising and the gain has automatically been boosted to compensate for the low light level. You may well have set the gain to -3db but if the auto has been activated it will override your gain setting. There is an 'auto' switch quite low down below the iris and focus control switches and you must have pressed it by mistake. Check the on screen symbals for 'full auto' or something similar.
The images were very dark, so I don't think the auto function would let that happen. It would go to +6 or +9db for sure, and I think I would know. I am pretty sure that's not the problem, but thanks anyway.
Must be something else wrong with your settings.
While the fireworks below are heavily compressed (1080p compressed to H.264 720p for upload and then compressed to VP6 720p) there is no grain. http://www.vimeo.com/1066619
You can see the setting in my description. The image is an example of shooting at night in dark with extreme contrast between bright fireworks and near black sky.