Originally Posted by darinp2
How are you using the term "dynamic range" here and can you put a number on it if it isn't just the number of steps? In another thread you said the following about 8 bit versus 10 bit:
Just wondering if what you mean in the first thing above is only that there are more steps between the endpoints or whether you are saying the endpoints are different and if different, whether you can put numbers (or approximate numbers) on the ratios of the endpoints between the two cases.
Its not as simple as saying the end stops are further apart. The thing you have to realise about video is that because of the limited encoding range you have to compromise the dynamic range according to image content to ensure you don't run up against precision limitations. (banding)
This is the main reason you can't transfer a film successfully into video just by the numbers. ( you need someone
referably a human being, eyeballing the process)
If you want to preserve detail towards black in a shot you will likely have to compromise some of the precision used towards peak white: this may also involve dropping the white point mapping in certain cases : thus dropping dynamic range. In some cases you may leave the white point mapping where it is but end up crushing a huge range off up to that point: dynamic range hasn't changed but the intensity steps in between have gone to pot. ( swap black point for white point in the above and you have the same issue at the lower end)
The point is that with something like print ( or DCi) you have a more consistent dynamic range on display with healthy encoding compared with video.
This to me this is what gives video its characteristic look. The dynamic range and the way its depicted has to slide about a fair bit from shot to shot, the more precision you have the more consistently you can display a larger healthier dynamic range. Video never looks like film for this reason: sure you might get the odd shot with minimal differences but across the range of imagery in an average film something has to give somewhere...most of the time.
I've just been grading a bunch of film shots to match video grade references ( for temp and feedback). To get the film into video is a pretty arbitrary curve mapping process (I'm just eyeballing matching straight from log not having to decide the grade itself). Sometimes they are transferring pretty much the entire dynamic range from the neg : but the resulting curve necessary to make the video have a pleasing contrast means there are huge swathes crushed, other times they have clipped off large regions towards black and/or white.
So sometimes its dynamic range limitation , other times its tone scale compromises : usually a bit of both banging about depending of image content.
The solidity and consistency that film ( and DCi) has in this regard should not be underestimated in terms of offering a superior psychovisual experience.
Video reminds me a lot of someone photocopying a photographic print and banging the brightness up and down.
You want numbers start with Lee's links and branch out from there: numbers bore me rigid most of the time. I am supposedly an artist not an engineer : I'm just able to masquerade as one on occasion.