On the path of understanding

[caheb]

Hi everyone, I've been using my AF100 for almost a year now. I'm self taught in video image, sometimes time it's hard, most of the time it's exciting, trying to learn stuff, spending a huge amount of time reading and shooting to understand simple things, I find it rewarding. First I'd say there is no magic camera, just ones with different tools, at various price ranges. And from what I understood (it's just a personal point of view, I might be wrong) for one price range you'll have basically cameras that deliver more or less the same quality (for example an AF100 and a Sony FS100) but have different built in tools. And I realise that more than the camera, it's the operator and the crew that make good pictures. Shooting with an AF100 require more carefulness and control than shooting with a 15000$ one, and so maybe more time, simple. And you have to shoot with what you can afford, isn't it?
All that to say that I love the AF100 and I'd probably love the FS100 if I had one. I just wanted to share some thoughts.
Now I would you to share some thoughts about what follows.
Recently I discovered the Art Adams' blog which features really intersting articles, and I also bought his Pocket Oneshot chart, which I find utterly useful. I read an article about S-logs, and since english is not my maternal language, it's possible that I got some stuff wrong. First I learn about the rec 709 bit bucket which he says is 5 stops, and if someone could ad some explanation to it it would be really nice, because, the af100 is a rec 709 cam, right. If I understood, the sensor can record 10 stops, and it will be remaped to fit in the five stop bucket, or did I get it wrong?
Then I wonder if cinelike d is a kind of emulation of an S-log curve in some ways. What do you think?

 

[Rowy]

I would stay away from Cinelike D - it's very noisy, and it isn't really anything like an S-log.

 

[caheb]

thanks for the share, yes cinelike D under poor lighting makes really bad footage. But when controlled carefully with a good amount of light it allows to produce really nice pictures! With no noise at all in the shadows, and a good handling of highlights.
I found a very interseting article on a french forum, that helped me to understand better the concept of the "bit bucket", and it deals with gain and noise problems!
A person asked for help on the forum because she was shooting a short with an AF100 and encountered noise problem, even in bright parts!. Turned out (after lowering Iso to 200) to be a monitoring problem...
Well that said a member posted an interesting reply.
He said that noise may come from a confusion between electronic functioning noise and a weak video signal. Then he takes an example : imagine a photosite whose intensity can vary from 0 to 20.
Camera conceptor says everything below 10 is black to avoid electronic functioning noise/ video signal confusion. We have a 10 possible stops range.
If you raise the gain, you lower the threshold of the blacks, it falls at 7, so there are 3 stops (from 7 to 10) which might be "confused". But we get a 13 possible stops range.
Then if you lower the gain tou raise the threshold of the blacks, it raises at 13, far from the "confusion" zone. But 20 is still the max value and from 13 to 20 there's only 7 stops left.
He says that all of that has to pass through the funnel of the video signal that might be 5-6 stops.