Question about the use of color and histogram (3 replies and 5 comments)
Hi Mr. Deakins and everyone else.
This is a question mostly for Mr. Deakins, but hopefully anyone can reply and help me out.
I'm in film school and have a great passion for cinematography and trying to learn as much as I can. And I've come a long way since I started, but there is something that I'm still struggling to understand. And that is reading the histogram properly.
I was hoping someone could give me any tips about how to understand it and read it better so I'm able to use the colors properly.
Exposure is a great topic. Can I ask what point about reading the histogram is troubling you?
Are you asking about exposure in general? Or you understand exposure, and now you are trying to understand how to apply a histogram into the equation?
Here to help, just asking to clarify. =)
More about understanding how to apply the histogram into the equation of the exposure and reading it properly. Sorry if I'm not phrasing the question right, this is how much trouble I have to understanding it.
No worries at all. The histogram is a massive subject and there are a lot of opinions on what is 'proper.' Rather than get technical here, it's good to start at a basic qualitative sense, then work into the quantitative.
So before going to far, do you understand the concept of light contrast? The balance of light and dark shapes in a composition/photograph/object/painting? For example, if I had a 3:1 ratio of light/dark or 10:1 dark/light etc?
Yes I feel very confident that I know about the contrast ratio.
4:1 = 2 f/stop difference correct?
Correct. Before getting into the color aspect - let's talk about gray-scale and how to spread that contrast over the histogram chart.
(I type out here because the box for responses get's too small to post. =) )
The histogram represents light to dark ratio and exposure from 0-100. This spectrum is called an IRE level from radio days, for whatever reason.
0 is the darkness - the 'clip' of the bottom of the camera's range before you will just see the native noise of the camera.
Over 100 means it will 'clip' and go to pure white, as at a certain point it will be overexposed.
55 is about mid gray on a lot of cameras.
So ideally, if you want a 'perfectly exposed' image, you would have your image sit in between these two 'goal posts.' The more spread out between these extremes means you are recording a wider ratio of contrast without clipping.
There is a lot of debate whether a skin tone should be at 55, or 30, or 70, or 100. Or if white contrast should be at 90, dark contrast flooring at 10. http://www.cinematography.com/index.php?showtopic=50788
Experiment with your camera, and find out how much contrast you'd like for things. Measure often using your light meter.
Proper lighting for film to me usually means exactly improper, so it really depends on the person. =)
Oh I see. That makes a lot of sense. Thank you for the explanation. I'll definetly have to read up about the IRE levels then. Another quick question. I recently made my first cinematography reel, can I link it here for your thoughts, opinions/notes?
I see a lot of people posting their work here for people to check out, so I think that may be an MO of the site. =)
I'll be on set for the next 5 days, but will check it out when i get back to the site.