Recently I shot my second online cinematography course, provisionally titled The Secrets of Cinematography, which will be out in the spring. In it I shoot on a Z Cam E2-F6, a full-frame camera. As far as I can remember, the only other time I’ve shot full-frame was for the miniature map in Above the Clouds, captured on a Canon 5D Mk III. So I thought this would be a good time to post a few facts about large-format, and a good excuse to get some more use out of this graphic I created for the course…
First of all, some definitions:
Super-35, about 24x14mm, has been the standard sensor size since digital cinematography took off in the noughties. It’s based on an analogue film standard which has its own complex history that I won’t go into here.
A large-format digital cinema camera is any that has a sensor larger than Super-35. It’s not to be confused with large-format still photography, which uses much bigger sensors/film than any currently existing for moving images.
Full-frame is a subset of large-format. Confusingly, this term does come from still photography, where it is used to identify digital sensors that are the same size as a frame of 35mm stills film: 36x24mm.
These are the differences you will notice shooting in large-format versus Super-35:
Lenses will have a wider field of view. (You’ll need to make sure your chosen lenses have a large enough image circle to cover your sensor.)
If you increase your focal length to get the same field of view you would have had on Super-35, perspective will be rendered exactly the same as it was on Super-35…
… but the depth of field will be shallower…
… and you may see more imperfections at the edges of frame where the lens is working harder. (A Super-35 sensor would crop these imperfections out.)
Picture noise will probably be finer and less noticeable due to the photosites being larger and more sensitive.
In the case of full-frame, the crop factor is 1.4. This means you should multiply your Super-35 focal length by 1.4 to find the lens that will give you the same field of view on a full-frame camera. (Some examples are given in the graphic above.) It also means that you can multiply your Super-35 T-stop by 1.4 to find the full-frame T-stop to match the depth of field.
“These are small,” Father Ted once tried to explain to Father Dougal, holding up toy cows, “but the ones out there are far away.” We may laugh at the gormless sitcom priest, but the chances are that we’ve all confounded size and distance, on screen at least.
The ship marooned in the desert in Close Encounters of the Third Kind, the cliff at the end of Tremors, the runways and planes visible through the windows of Die Hard 2’s control tower, the helicopter on the boat in The Wolf of Wall Street, even the beached whale in Mega Shark Versus Giant Octopus – all are small, not far away.
The most familiar forced perspective effect is the holiday snap of a friend or family member picking up the Eiffel Tower between thumb and forefinger, or trying to right the Leaning Tower of Pisa. By composing the image so that a close subject (the person) appears to be in physical contact with a distant subject (the landmark), the latter appears to be as close as the former, and therefore much smaller than it really is.
Architects have been playing tricks with perspective for centuries. Italy’s Palazzo Spada, for example, uses diminishing columns and a ramped floor to make a 26ft corridor look 100ft long. Many film sets – such as the basement of clones in Moon – have used the exact same technique to squeeze extra depth out of limited studio space or construction resources.
Even a set that is entirely miniature can benefit from forced perspective, with a larger scale being used in the foreground and a smaller one in the background, increasing the perceived depth. For example, The Terminator’s “Future War” scenes employ skulls of varying size, with background ruins on an even smaller scale.
An early cinematic display of forced perspective was the 1908 short Princess Nicotine, in which a fairy who appears to be cavorting on a man’s tabletop is actually a reflection in a distant mirror. “The little fairy moves so realistically that she cannot be explained away by assuming that she is a doll,” remarked a Scientific American article of the time, “and yet it is impossible to understand how she can be a living being, because of her small stature.”
During the 1950s, B movies featuring fantastically shrunk or enlarged characters made full use of forced perspective, as did the Disney musical Darby O’Gill and the Little People. VFX supervisor Peter Ellenshaw, interviewed for a 1994 episode of Movie Magic, remembered the challenges of creating sufficient depth of field to sell the illusion: “You had to focus both on the background and the foreground [simultaneously]. It was very difficult. We had to use so much light on set that eventually we blew the circuit-breakers in the Burbank power station.”
Randall William Cook was inspired years later by Ellenshaw’s work when he was called upon to realise quarter-scale demonic minions for the 1987 horror movie The Gate. Faced with a tiny budget, Cook devised in-camera solutions with human characters on raised foreground platforms, and costumed minions on giant set-pieces further back, all carefully designed so that the join was undetectable. As the contemporary coverage in Cinefex magazine noted, “One of the advantages of a well-executed forced perspective shot is that the final product requires no optical work and can therefore be viewed along with the next day’s rushes.”
A subgroup of forced perspective effects is the hanging miniature – a small-scale model suspended in front of camera, typically as a set extension. The 1925 version of Ben Hur used this technique for wide shots of the iconic chariot race. The arena of the Circus Maximus was full size, but in front of and above it was hung a miniature spectators’ gallery containing 10,000 tiny puppets which could stand and wave as required.
Doctor Who used foreground miniatures throughout its classic run, often more successfully than it used the yellow-fringed chromakey of the time. Earthly miniatures like radar dishes, missile launchers and big tops were captured on location, in camera, with real skies and landscapes behind them. The heroes convincingly disembark from an alien spaceship in the Tom Baker classic “Terror of the Zygons” by means of a foreground miniature and the actors jumping off the back of a van in the distance. A third-scale Tardis was employed in a similar way when the production wanted to save shipping costs on a 1984 location shoot on Lanzarote.
Even 60 years on from Ben Hur, Aliens employed the same technique to show the xenomorph-encrusted roof in the power plant nest scene. The shot – which fooled studio executives so utterly that they complained about extravagant spending on huge sets – required small lights to be moved across the miniature in sync with the actors’ head-torches.
The Aliens shot also featured a tilt-down, something only possible with forced perspective if the camera pivots around its nodal point – the point within the lens where the light focuses. Any other type of camera movement gives the game away due to parallax, the optical phenomenon which makes closer objects move through a field of view more quickly than distant ones.
The 1993 remake of Attack of the 50ft Woman made use of a nodal pan to follow Daniel Baldwin to the edge of an outdoor swimming pool which a giant Daryl Hannah is using as a bath. A 1/8th-scale pool with Hannah in was mounted on a raised platform to perfectly align on camera with the real poolside beyond, where Baldwin stood.
The immediacy of forced perspective, allowing actors of different scales to riff off each other in real time, made it the perfect choice for the seasonal comedy Elf. The technique is not without its disadvantages, however. “The first day of trying, the production lost a whole day setting up one shot and never captured it,” recalls VFX supervisor Joe Bauer in the recent documentary Holiday Movies That Made Us.
Elf’s studio, New Line, was reportedly concerned that the forced perspective shots would never work, but given what a certain Peter Jackson was doing for that same studio at the same time, they probably shouldn’t have worried.
The Lord of the Rings employed a variety of techniques to sell the hobbits and dwarves as smaller than their human friends, but it was in the field of forced perspective that the trilogy was truly groundbreaking. One example was an extended cart built to accommodate Ian McKellen’s Gandalf and Elijah Wood’s supposedly-diminutive Frodo. “You could get Gandalf and Frodo sitting side by side apparently, although in fact Elijah Wood was sitting much further back from the camera than Gandalf,” explains producer Barrie Osborne in the trilogy’s extensive DVD extras.
Jackson insisted on the freedom to move his camera, so his team developed a computer-controlled system that would correct the tell-tale parallax. “You have the camera on a motion-controlled dolly, making it move in and out or side to side,” reveals VFX DP Brian Van’t Hul, “but you have another, smaller dolly [with one of the actors on] that’s electronically hooked to it and does the exact same motion but sort of in a counter movement.”
Forced perspective is still alive and kicking today. For Star Wars Episode IX: The Rise of Skywalker, production designer Kevin Jenkins built a 5ft sand-crawler for shooting in the Jordan Desert. “It was placed on a dressed table at height,” he explained on Twitter, “and the Jawa extras were shot at the same time a calculated distance back from the mini. A very fine powdery sand was dressed around for scale. We even made a roller to make mini track prints! Love miniatures :)”
Today I’m investigating the so-called normal (a.k.a. standard) lens, finding out exactly what it is, the history behind it, and how it’s relevant to contemporary cinematographers.
The Normal lens in still photography
A normal lens is one whose focal length is equal to the measurement across the diagonal of the recorded image. This gives an angle of view of about 53°, which is roughly equivalent to that of the human eye, at least the angle within which the eye can see detail. If a photo taken with a normal lens is printed and held up in front of the real scene, with the distance from the observer to the print being equal to the diagonal of the print, then objects in the photo will look exactly the same size as the real objects.
Lenses with a shorter focal length than the normal are known as wide-angle. Lenses with a greater focal length than the normal are considered to be long lenses. (Sometimes you will hear the term telephoto used interchangeably with long lens, but a telephoto lens is technically one which has a focal length greater than its physical length.)
A still 35mm negative is 43.3mm across the diagonal, but this got rounded up quite a bit — by Leica inventor Oskar Barnack — so that 50mm is widely considered to be the normal lens in the photography world. Indeed, some photographers rarely stray from the 50mm. For some this is simply because of its convenience; it is the easiest length of lens to manufacture, and therefore the cheapest and lightest. Because it’s neither too short nor too long, all types of compositions can be achieved with it. Other photographers are more dogmatic, considering a normal lens the only authentic way to capture an image, believing that any other length falsifies or distorts perspective.
The normal lens in cinematography
SMPTE (the Society of Motion Picture and Television Engineers), or indeed SMPE as it was back then, decided almost a century ago that a normal lens for motion pictures should be one with a focal length equal to twice the image diagonal. They reasoned that this would give a natural field of view to a cinema-goer sitting in the middle of the auditorium, halfway between screen and projector (the latter conventionally fitted with a lens twice the length of the camera’s normal lens).
A Super-35 digital cinema sensor – in common with 35mm motion picture film – has a diagonal of about 28mm. According to SMPE, this gives us a normal focal length of 56mm. Acclaimed twentieth century directors like Hitchcock, Robert Bresson and Yasujiro Ozu were proponents of roughly this focal length, 50mm to be more precise, believing it to have the most natural field of view.
Of course, the 1920s SMPE committee, living in a world where films were only screened in cinemas, could never have predicted the myriad devices on which movies are watched today. Right now I’m viewing my computer monitor from a distance about equal to the diagonal of the screen, but to hold my phone at the distance of its diagonal would make it uncomfortably close to my face. Large movie screens are still closer to most of the audience than their diagonal measurement, just as they were in the twenties, but smaller multiplex screens may be further away than their diagonals, and TV screens vary wildly in size and viewing distance.
The new normal
To land in the middle of the various viewing distances common today, I would argue that filmmakers should revert to the photography standard of a normal focal length equal to the diagonal, so 28mm for a Super-35 sensor.
According to Noam Kroll, “Spielberg, Scorsese, Orson Wells, Malick, and many other A-list directors have cited the 28mm lens as one of their most frequently used and in some cases a favorite [sic]”.
I have certainly found lenses around that length to be the most useful on set.A 32mm is often my first choice for handheld, Steadicam, or anything approaching a POV. It’s great for wides because it compresses things a little and crops out unnecessary information while still taking plenty of the scene in. It’s also good for mids and medium close-ups, making the viewer feel involved in the conversation.
When I had to commit to a single prime lens to seal up in a splash housing for a critical ocean scene in The Little Mermaid, I quickly chose a 32mm, knowing that I could get wides and tights just by repositioning myself.
I’ve found a 32mm useful in situations where coverage was limited. Many scenes in Above the Clouds were captured as a simple shot-reverse: both mids, both on the 32mm. This was done partly to save time, partly because most of the sets were cramped, and partly because it was a very effective way to get close to the characters without losing the body language, which was essential for the comedy. We basically combined the virtues of wides and close-ups into a single shot size!
In addition to the normal lens’ own virtues, I believe that it serves as a useful marker post between wide lenses and long lenses. In the same way that an editor should have a reason to cut, in a perfect world a cinematographer should have a reason to deviate from the normal lens. Choose a lens shorter than the normal and you are deliberately choosing to expand the space, to make things grander, to enhance perspective and push planes apart. Select a lens longer than the normal and you’re opting for portraiture, compression, stylisation, maybe even claustrophobia. Thinking about all this consciously and consistently throughout a production can add immeasurably to the impact of the story.