The large format takeover is here with cameras like the Alexa LF and Red Monstro plus a healthy complement of lenses to support their enlarged sensors from Cooke, Zeiss, Leica, and a lot more. Maybe for me it’s just too much change too fast, but I keep asking myself the question: Why? Of course there are several obvious changes that come along with the large format cameras like the shallower depth of field, lower pixel density, and consequently better low light performance, but there’s another factor that’s been gnawing at me for a while. It’s that pesky large format “PeRsPeCtIvE.”
Truth be told, I’ve been getting into fights with other cinematographers about this for years because there’s so much misinformation about it. It’s this thought (delusion perhaps?) that when you use a larger sensor you unlock a special, super awesome, more life-like perspective. I see it everywhere and it’s so strange because it’s actually just...not true?
Remember those 35mm adapters people used a decade ago before the 5D Mk. II to get low budget shallow depth of field. The idea is that you get a 35mm photo lens that projects an image onto a 35mm ground glass, just like the optical viewfinder of a DSLR. It produces an image with full frame DOF. Then your small sensor video setup simply films the ground glass. Voila, cheap cinematic depth of field! Well, I came across a post on Reddit recently wherein someone was billing their DIY rig as a homemade IMAX camera. He popped a medium format lens onto one of those adapters with a huge 70mm ground glass and determined he had achieved the IMAX perspective—that beautiful compression of space that’s just oh so hard to attain. Mind you, we’re not talking about depth of field here. His camera rig would get you a super shallow DOF, but a new perspective? No. He emboldened me to finally speak up about this in a public forum because it was getting out of hand. Also the people should really know the truth!
The depth of field changes with sensor size, but everything else is the same. The nose, the head, the doorway all the same size.
For those of you unfamiliar with this discussion of perspective, I did a quick Google search and turned up some—ostensibly educational—links that are spreading these lies. If you must, you can check them out here, here, here and here. That last one even has side by side pictures of three different sensor sizes with identical compositions (pictured above). Not to be deterred, the writer is so set in their conviction that they go on to say, “When using larger formats, you are using longer focal lengths to achieve the same field of view, which means a more natural perspective that more closely resembles the field of view of our own eye-sight.” It sounds so persuasive, I’m almost inclined to believe it.
I totally see where the confusion comes from though. It’s a fundamental misunderstanding of what exactly is happening when we use photographic techniques to compress and expand the depth we perceive on camera. The common knowledge is that telephoto lenses compress space, while wide angle lenses expand it. That’s not true either. I know what you’re thinking: how could that be? You’ve seen with your own eyes the effects of your 28mm compared to your 85. I’m sorry to say it’s actually not the lens at all. It’s you. It’s where you put the camera in relation to the subject. The farther your camera is from the subject the more compressed the depth is going to be. The closer you put the camera the more expanded the depth will be. Your focal length has literally (and I mean without exception, not even for fisheyes) no affect on this. The reality is that when you put a telephoto lens on, you’re generally pointing the camera at a subject that is far away; that’s why we associate this compression with telephoto lenses.
Doubling back around to the main point, because the focal length has nothing to do with perspective, shooting on a format that allows you to use longer focal lengths ALSO has nothing to do with perspective. To illustrate this I made you all this easy to understand diagram showing how the field of view is the same on both a medium format (MF) and a 35mm camera. To get the same composition and the same perspective, the camera stays in the same place, you compensate with the focal length and the frame will be identical. As you can see the little birdie is just out of picture, the bunny is head to toe in the foreground and the tree is in the background with the same amount of space on the top and bottom regardless of the format you shoot in. Ok? Can we put this to rest now?
You’ll notice in the crude diagram I made that the sensors of the cameras are not the same distance from the subject. The MF camera’s sensor is farther away due to the longer focal length. It seems like this would cause a small change in the composition, but actually the opposite is true. I’ve seen other versions of this diagram that get this wrong, such as the one above taken from the April ‘16 issue of American Cinematographer magazine. In their diagram they keep the sensor the same distance from the subject regardless of the sensor size and focal length. When they draw out the field of view, the angles are not identical. It actually makes the implication that there would be some difference in the perspective from a Super 16 compared to a Super 35 camera, even though the findings of their test state otherwise. That’s because it’s actually the entrance pupil of the lens (sometimes erroneously referred to as the optical center or nodal point) that should be kept consistent in order to get the exact same composition.
GLOSSARY OF TERMS (in my own words):
Alexa LF: Latest version of the successful Alexa digital cinema camera from German manufacturer, “Arri.” The LF stands for Large Format because it uses a “full frame” sensor, which is larger than the traditional cinematographic standard: Super 35.
Depth of Field (DOF): The range of distances in front of the lens that are rendered acceptably in focus.
Entrance Pupil: Also called the perspective point, it is the vertex of the lens’s angle of view. In other words, it is the single point from which the camera views the world.
Field of View (FOV): Also called the Angle of View. It’s the angle in front of the camera that defines the outer limits of the frame. It is determined to by a combination of the sensor size and the focal length of the lens. Because cameras rarely have a square sensor, a camera system will generally have a different horizontal and vertical angle of view.
Focal Length: The distance from the rear focal point to the rear principal point of a lens. Determines the magnification or how zoomed in an image is rendered.
Format: Refers to the size of the sensor the image is being recorded to.
Full Frame: A photography format originally using 35mm film run horizontally through the camera. The negative size for each frame is 36mmx24mm. This was carried over to digital photography cameras and is still used as a standard for digital sensors today. Recently it has become popular to implement this standard in digital cinema cameras.
Ground Glass: A translucent piece of glass that is placed behind a lens. It allows one to see the image coming from the back of the lens without the image needing to be recorded by a sensor.
IMAX: The largest available format one can currently shoot on in the world of filmmaking. It uses 65mm film run horizontally through the camera for a negative area of 70.41mmx52.63mm. *Note: Avengers: Endgame was shot with the digital Alexa 65, but was still somehow advertised as shot with “IMAX” cameras. Go figure.
Large Format: Traditionally used in analog photography to describe a film format with a negative of at least 4”x5.” Now co-opted by high end cine camera manufacturers to describe digital cameras with a sensor larger than a traditional Super 35 camera. These sensors are all significantly smaller than the original 4”x5” standard.
Medium Format (MF): A photography format that uses 120 film (about 6cm wide) that is run either vertically or horizontally with a wide range of formats including 6x4.5cm, 6x6cm, and 6x7cm. Often medium format lenses are adapted for use with IMAX and other cinema formats larger than full frame.
Red Monstro: Latest digital cinema camera from American manufacturer, “Red.” Boasts a sensor actually quite a bit larger than “full frame.”
Perspective: The relative size as it appears on camera of objects at different distances from the lens. *Note: The terms “compression/expansion of space/depth” are used to describe the perspective of an image.
Pixel Density: How many pixels on a sensor per square area of sensor space.
Sensor: The digital imaging chip within a camera that records the light coming off the lens. The digital equivalent to film. *Note: I do sometimes use this agnostically to describe either a digital chip or a piece of film. Not sure if that’s entirely correct, but it’s easier.
Super 16: A motion picture camera format originally intended for amateur and low budget usage. It uses 16mm film run vertically through the camera with a negative size of 12.52mmx7.41mm.
Super 35: A motion picture camera format that uses 35mm film run vertically through the camera with a negative size of 24.89mmx18.66mm. This was the Hollywood standard for decades. It was adopted for digital cinema cameras, with a significant crop in the height of the frame to reflect the trend toward widescreen filmmaking. It is now being phased out by full frame digital cinema cameras.
Telephoto Lens: A lens with a relatively long focal length for the format it’s used on. Creates the effect of the image being more zoomed in.
Wide Angle Lens: A lens with a relatively short focal length for the format it’s used on. Creates the effect of the image being zoomed out.