How do film cameras have no grain on movies?

[Raymond Lin]

Watching erm...Avril Lavgine Live in Concert DVD and obviously the lighting is dark with a few spot lights but i don't see hardly any grain. Since the camera (camcorder) is run at 1/24th second right? and then the same film adapts to the light even when you move outside to day light too (I presume you can), how does it go that??? Traditional film will struggle to run at a constant 1/24 and be as clear in the dark and outdoors.

 

[StewartR]

I think it's probably because the picture is such low resolution. Standard (non-HD) TV only has about 0.3-0.4 megapixels per frame.

 

[Raymond Lin]

There must also be a lot of give in the film, since each second can be different to the next in terms of lighting with all the spot lights on stage, how does it adapt ??? ! There doesn't seem to be blown outs or under exposed shots.

 

[nine0nine]

noise/grain is 'random' on each frame but the subject is not, so therefore at 24fps you are getting the grain in a different place 24 times a second, making it un-noticable.

 

[Jimmy_Lemon]

I don't think the Avril Lavigne concert would have been shot on film btw - but the lack of noise has always interested me too. The semi-pro video cameras I use never show noise and can work in VERY low light, much darker than I would be able to photograph in. I am guessing it is down to the low output size and the way the image is processed. I have noticed before when filming that if you up the "gain" (almost like increasing the ISO on a DSLR) then you will see noise in the viewfinder but it won't show on the tape :| also on a side note the camera I use a lot (Sony DSR 300) seems to have a much highter dynamic range than any digital stills camera I have ever seen - I probably should read up why, but can't be arsed.

 

[Nod]

A combination of low resolution, large photosites and agressive NR, all of which will be unnoticeable at 24fps. Grab a single frame from a sequence and look closely at it and I'll bet it'll show some noise.

 

[Arkady]

Do a still 'grab' and you'll see horrendous amounts of grain - because the image is moving the brain interprets it differently from a still image and as others mentioned the grain is random and appears in different places in the frame...it therefore appears 'smoother' than a still image shot on the same ISO-equivalent film (or digital capture).
In some TV series shot indoors you can 'see' or detect that a higher-ISO stock is being used if you look carefully.
Plus the optics for high-end video and movie work cost tens of thousands of pounds...they have very wide apertures...