[Cliff Olson]

I've noticed that alot of times - especially on HDNet (via Directv), when they're filming in dimly lit areas, there's a LOT of video noise. What causes this? Is this a result of compression or something else? I know that when filming movies (and transferring to DVD), there is much better lighting, but when there are dark scenes, I don't notice any noise - or at least it's not distracting. Some HDNet programming is almost unwatchable because it's so noisy. TIA.

 

[samiam95124]

Its analog. Yes, it is simply the natural noise of the camera that shows

up when the camera electronics are attempting to adust the gain up on

a low light signal. You can see this in a standard consumer camera as

well.

 

[Megahurts]

Factors that affect video quality in a digital system.


Quality of the input video- Amplitude, dc level, bandwidth, ringing, jitter, noise, composite\\component decoding artifacts, prefiltering to eliminate these problems.


Nature of the input video- Picture spatial and temporal complexity.


Encoding parameters used- Profile/level, field/frame, output data rate, GOP.


Encoding algorithm- Speed required, hardware vs. software, multiple pass and algorithm design.


All of these factors add up to video quality and what might be considered noise in your DTV signal. It may be presumptuous to assume that the cameras used in EFP are set in automatic mode to adjust gain. Digital noise is a bit different than that of its analog brethren. All of this combines to affect video quality.

MHz

 

[Cliff Olson]

Thanks for the explanation guys. I just remembered that I did see a lot of this noise in the "Band of Brothers" DVD Set too.

 

[balazer]

The randomness of the photons becomes more apparent as their rate decreases. You see the same thing with your eyes, or at least I do. Maybe something is wrong with my eyes!