Reducing grain sony A7

Steve's comments about noise reduction are spot on.

I've got Neat, have used it for several years. Excellent app and plugin, tons of settings. Setting it to three frames temporal so it looks at multiple frames to decide what's noise makes the reduction better but takes more processing.

Neil

as to fixing the noise - there are a number of plugins available for purchase that can reduce video noise.

Neat video is apparently good - though I've not used it.

Red Giant Denoiser works well.

BorisFX have one in the Continuum package.

RevisionFX have one too.

And for free if you want to go via After Effects - there is a good video denoiser as part of AE.

And while I've not yet explored its noise reduction capabilities Topaz Video Enhance can reduce noise.

It's a stand alone application though.

All noise reduction effects need to be used sparingly to avoid adding unwanted artifacts. Like softening, motion blur etc.

So adjust accordingly. 

Even with that 1.8 lens, there just isn't enough light hitting the sensor. You have to have adequate exposure of the sensor to get good quality images.

So you either need more light sources, or a longer shutter speed. Or both.

Most people don't realize that for instance outside night shots for TV/movies have a TON of added lights.  Shooting at night is technically very, very difficult.

Neil