Guest Article: Cinematography DeCal Week 3, Camera is Rolling!
Howdy y’all! Adam here. I’ll be your host for this weeks edition of…. drummmmmmmroolllllll……..
THE CINEMATOGRAPHY DECAL ARTICLE!!!
Alright, well – now that I’ve wrapped you all in with my exciting use of capitalized bold letters and dramatic sound effects (sound effects not included) let’s go right into this weeks topic: THE CAMERA.
DUN, DUN, DUN….. (for best results passionately shout the sound effects out loud)
Corny sound effects aside, what exactly did we learn during week 3? Well, just about everything a self-respecting cinematographer NEEDS to know about camera operation. The most basic basics are how to set and adjust ISO, aperture, shutter speed, and white balance. What are these 4 things? And, how do they relate to each other? GOOD QUESTION!
Here’s a CAMERA CRASH COURSE!
First let’s look at your camera’s sensor.
ISO–is the measure of a photographic film’s sensitivity to light. The higher the ISO the more sensitive the film stock/digital sensor is to light photons. NOTE: shooting on a higher ISO will allow you to capture more light but you will also give you more grain, …
Assuming you are shooting on digital, you can adjust your ISO. Mess with the sensor on your digital camera and use the zoom function to see in detail how adjusting ISO affects light sensitivity and image quality. The take-home message here is that a higher ISO will give you a brighter exposure with the drawback that you will get more noise.
Moving on to a lens property:
Aperture–refers to the hole or opening in your camera lens through which light travels. All the light that hits the sensor or film inside the camera must first pass through an opening in the lens. You can adjust the width of this opening by changing the f-stops on your lens.
Note that changing your aperture not only affects how much light you let hit the film/sensor but also your depth of field (how much of the space in front of the camera is in focus). Look at the diagram below for some clarification.
[[EDIT: f/1.0 is not letting through 100% of the light; rather, it means aperture diameter and focal length have a ration of 1.0 . You can just remember “the lower the f-stop, the more light can pass through.]]
See that thing called the “focus plane?” That’s the area in front of the lens that will have a crisp focus. Everything outside of it will not be in focus. Notice the difference between f22 (the violet area?) and f/1.4 (the red area).
I (foolishly) like to shoot with the shallowest depth of field possible. This means that I constantly have to pull focus in order to keep a sharp focus on what’s in front of me. This also means that I’m left with a lot of out of focus shots. Hmm.. but what about my shots where all the motion looks super blurry or strobe lighty?
I’m glad you asked! That brings us to shutter speed!
Shutter Speed–refers to how long the sensor is exposed to light, for each frame. It is measured in fractions of a second. Helpful things to know: What you will notice the most when you play with your shutter speed is that it affects both the amount of light in the exposure and the amount of motion blur.
To answer Toby’s question: Why 1/48th? It’s because when the frames are put together into a movie, shooting at 1/48th is a tradition from shooting 24 frames per second on film, and gives the illusion of natural motion blur – like we experience it in everyday life. Try this. Focus on these words and then take your left hand and wave it back in forth as fast as you can in front of your face. It will probably be one big blur that passes by so fast that you can still read the words behind it. We naturally experience motion blur like this.
Shooting on a slow shutter speed will leave exaggerated ghost trails behind a moving object. Shooting too fast won’t leave any, so you will feel like you are at rave. If that doesn’t explain it. Maybe this cute baby will be able to help.
Well, now that that’s clear, I want to share with you an awesome chart that will help you see how ISO, aperture, and shutter speed are related. Take a second to study the graphic below.
The cool thing about this graphic is that ISO, aperture and shutter speed are color coded so you can clearly see that ISO affects Noise, Aperture affects Depth of Field (DoF), and Shutter Speed affects Motion Blur. But even cooler is that it helps you see how these three come together to give you your Exposure Value, (EV), the amount of light picked up by the sensor.
So say I have a great exposure but the background is ugly and cluttered and it takes away from the shot. Well, I could open up the aperture and that would give me a smaller depth of field so only the foreground is in focus. (For example, look at the difference between f/5.6 and f/2.8 in the chart above) The problem is that going to f/2.8 will not only change the DOF but also let in more light. To balance that I would have to get a faster shutter speed (so that the excess light would hit the sensor for less time) and/or drop my ISO (so the sensor will be less sensitive to the light.) Note how any choice will lead to a side effect (i.e. it will change the amount of motion blur and/or noise) The task of the cinematographer is to balance these settings, like you would a scale, so that your shot has the look and feel that you imagined. Alternatively, you can also put a Neutral Density filter in front of the lens, in order to compensate a wide open Aperture.
This brings me to my last setting…. White Balance:
White Balance–is your cameras setting which adjusts its sensitivity to color. Adjusting your white balance will change the color temperature and/or tint of your image.
Here’s an example of Presets vs. adjusting Kelvin (unit of Color Temperature)
Going through your camera’s presets and then attempting to color balance yourself is a great way to get more familiar with what white balance is.
That’s all for now folks. Remember to follow the link to the rest of Toby’s lecture slides. And stay tuned for more adventures from…..
THE CINEMATOGRAPHY DECAL!!!!
DUN, DUN, Ditty, Ditty, DUN, DUN!! 🙂
Adam Sommer is studying Psychology and Film at UC Berkeley. He enjoys long walks on the beach, good wine and smooth jazz. And filmmaking, of course. Check out his First Cinematography Reel if you like!