50D is a great camera for shooting RAW with Magic Lantern hack but, being an old camera, has a bit more noise than competition, which becomes evident in low light conditions.
In additions the noise has a disturbing pattern consisting in vertical and horizontal stripes of noise, making it look digital and not filmic.
So I read many posts about the Dark Frame Subtraction tecnique in photography, which uses two shots one on top of the other: lower one is the original photo, upper is a toatlly dark photo made with same settings but with cap on the lens.
This “dark frame” photo has some light spots, the more evident are the hot pixels, the less evident are the noise.
The dark frame is blended with the original photo in subtraction mode, so where the frame is black the photo is seen correctly, otherwise brighter pixels are brought down with the subtraction procedure, resulting in a photo without hot pixels (at least they are no more bright) and less noise.
In some forums (like Magic Lantern one) somebody claimed that we could do the same for video, making the noise less disturbing.
I decided to make an attempt, but as you can see in the video above adding the dark frame layer is useless: the noise is similar but changes every frame, giving no opportunity with a secon clip to denoise the exact pixel at the exact moment.
The subtraction was made with DaVinci Resolve.
Youtube did a heavy compression, so if you want to see the video at its full quality download it here: