Contrast ratio

Posted on by

Home Forums Lighting Contrast ratio

  • Creator
    Topic
  • #215132
    LucaM
    Participant

      Since I tend to embark in strange adventures I decided to write and direct my first short movie, but unfortunately I’m doing it with zero budget. Yes, unexperienced and with no budget: i’m aware that I created the perfect receipt for a complete disaster. Who knows, maybe i’m going to create the new “The Room” , ah ah!

      Jokes apart, I’m doing my best to learn and understand and to find a solution to all the problems I’m facing. I’d like to realize something nice, not just waste some time. The greatest difficulty i’m trying to solve it’s the lighting, since i have no real lights (but i’m building my own soft lights with a bit of DIY) . I realized that thinking in terms of contrast ratio makes the lighting planning easier to me, since it  relates one light to the others and helps me understand what’s the role and meaning of each light in its context.  That’s way i’ve got a couple of questions about the contrast ratio.

      1) Given that of course the global effect, mood, style of the scene are fundamental in the planning, is the contrast ratio a factor you  actually consider in the planning of a scene lighting?

      2) Is it better to keep the contrast constant in all the scenes to preserve the visual omogenity or is it better to adapt the contrast to the mood of the scenes, if it changes?

    Viewing 6 replies - 1 through 6 (of 6 total)
    • Author
      Replies
    • #215145
      Roger Deakins
      Keymaster

        I consider contrast when I am staring a project and when I light a scene but mine is not a mathematical approach. Some cinematographers my work from a ratio when they light but I just use my eye, judge the way I want a shot to look by looking at it.

        Whether you maintain the contrast of the image through the whole film is up to the individual and the script. Its impossible to give one sweeping answer.

        #215151
        Rob-Webster
        Participant

          I would also like to add, if i may, that calculating contrast ratios or using a more instinctive approach (as Roger described) is a totally personal thing. You have to find the right approach for how you see things.

           

          I suspect that if you treat contrast ratio dogmatically and try to light every shot at a 4:1 ratio (for example), you will A) Spend forever looking at numbers and not considering the image, and (B) End up with a very boring looking film.

          Contrast ratio, in my mind, is more like a guide, its an area to aim that rather than a strict mathematical decision

          #215152
          ThisGuy321
          Participant

            The film school I went to years ago took a very mathematical approach to contrast ratios, which was very helpful from a fundamental learning standpoint. However, because the approach to it was treated almost dogmatically, every short film felt strangely over lit (unnecessary fill and atmosphere light everywhere regardless of low or high key scenes) in order to try and capture the accurate numbers. Granted, you could just blame most of the problem on film students being inexperienced. But everyone was afraid to let anything fall into darkness (even if it was a 4:1 scenario) if the numbers in the exposure didn’t match up exactly. It took having a working DP in the industry to come in for a semester to break the habit by asking us, “Does it look good and feel right for the story? No? Then why are you lighting it that?”

            • This reply was modified 5 months, 4 weeks ago by ThisGuy321.
            • This reply was modified 5 months, 4 weeks ago by ThisGuy321.
            • This reply was modified 5 months, 4 weeks ago by ThisGuy321.
            #215157
            dmullenasc
            Participant

              I’ve never used contrast ratios because that requires some conversion math… but in terms of measuring and noting the shadow level, if that’s done, it’s more about matching coverage. You light the wider shot by eye and create the contrast you want, but sometimes when you start covering a scene, you might take notes on the shadow level versus the key for matching purposes, especially if you are shooting VFX elements for compositing.

              #215160
              LucaM
              Participant

                Thanks to you all for your replies, you all gave me interesting things to reflect upon! I see the risk of giving more importance to the math than to the image. Perhaps it seems an interesting aspect to me because i have no experience and i think that at the beginnings (no matter in which field)  “magic formulas” seems a very useful tool to look for. And besides that i’m a science and maths teacher and so i really love formulas, ah ah.
                From your comments it seems to me that (in my particular case) contrast ratio could be the starting point to set the scene and not the final step, since i think it could give me an approximate idea of how to begin to light the scene.

                About the second part (keeping the ratio or adapting to the scenes) i am trying to study movies i like to see what choices they made. What i hope to achieve is to avoid both a boring homogeneity of the images and a messy variety of them and find the right balance. Which at the moment looks like a very complicated achievement to obtain, ah ah!

                #215259
                Rob-Webster
                Participant

                  I think contrast ratio is one of those things you learn, and then it becomes instinctive.

                Viewing 6 replies - 1 through 6 (of 6 total)
                • You must be logged in to reply to this topic.