cinematography

“The Little Mermaid”: Shooting Shirley

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The Little Mermaid, an independent live-action take on the Hans Christian Andersen fairytale, is now showing in cinemas across the USA. To mark the release, over the next few weeks I’ll be posting a series of articles about my cinematography of the film, using extracts from the diary I kept during production.

In this first instalment I’ll focus on the “pre-shoot”, two days of capturing the present-day scenes, undertaken a few weeks before principal photography began. For these scenes, we were all very excited to be working with bona fide Hollywood royalty in the form of Shirley MacLaine. Since debuting in the 1955 Hitchcock comedy The Trouble with Harry (and winning a Golden Globe), Shirley’s career has taken in six Oscar nominations as well as a win for Terms of Endearment, plus an AFI Life Achievement Award, two Baftas, an Emmy and several more Golden Globes.

No pressure then….

 

Saturday

Shirley is installed at a five-star hotel in downtown Savannah for hair, make-up and wardrobe tests. Taking it easy at the studio, I get a call from the UPM telling me that Shirley wants to meet me. Nervously I transfer my lighting reference images (including screen grabs I gathered last week from her previous movies) to my iPad and await my car.

When I get to the hotel I bump into her and the rest of the crew in the hall. Plunging straight in, I shake her hand and introduce myself as “Neil Oseman, the DP”. Evidently not hearing that last bit, and presuming I’m a PA or possibly a fan, she looks me up and down and asks me who I am. I repeat that I am the director of photography. “You’re so young!” she exclaims, laughing at her mistake.

“Well, I’ve been doing this for fifteen years,” I reply, all too aware of how short my career is compared with hers.

“Which pictures? Tell me,” she says.

Again acutely aware that my credits list isn’t going to sound very impressive to her, I mention Heretiks, and Ren: The Girl with the Mark and mutter something about doing lots of features.

To my great relief she doesn’t press the point, instead asking what I think of the wig and make-up she’s wearing. I ask her to step into the daylight, and assure her that it looks good, but that I’d like to warm up her skin tone a little with the lighting, an idea she responds well to.

Satisfied, Shirley moves on to other things, and I hang out in a meeting room at the hotel drawing storyboards, until it’s time for a production meeting.

 

SUNDAY

The present-day scenes were shot on Arri Alexas using Zeiss Super Speed Mark I primes and an Angenieux Optimo zoom, diffused with Tiffen Soft FX filters.

I arrive on location before even the early crew call of 8am, with my gaffer Mike Horton. His and key grip Jason Batey’s teams have rigged a dark box around the beach house’s deck/balcony so we can shoot day-for-night interiors.

At 10am Shirley arrives, blocks the scene, then goes off to hair and makeup. We’re starting with close-ups of her, so the grip and electric teams come in and build a book light. (This is a V-shaped arrangement of bounce and diffusion material, resembling an open book, which greatly softens the light fired into it.) When we start to turn over and Shirley watches playback, I’m gratified to find she is very happy with how she looks on camera. We shoot out all her close-ups, then bring in the little girls playing opposite her and block the wide shots.

In the lefthand foreground here is the 2K source for the book light. In the top right you can see the diffusion frame it’s firing through, and you can just make out the poly or rag we attached to the wall to bounce the light back onto Shirley (in the white nightgown). The net in the upper centre is cutting some light off the background. The camera can just be seen on the right of the photo.

As time begins to crunch, I fall back on cross-backlighting as a quick no-brainer solution to get the wide shot looking good. It’s so important to have these lighting templates up your sleeve when the pressure’s on. (Later on in this blog series I’ll discuss the use of cross-backlighting in several other scenes in the movie.)

For a little while it looks like we might not make the day, but I suggest a way to maximise the beautiful beach view at twilight and get the story beats covered in one two-camera set-up. The shot feels like something out of a classic old movie. Shirley MacLaine walking off into the sunset! Everyone loves how it looks, including Shirley. The praise of an actor as experienced as her is high praise indeed, and it makes my day!

 

Monday

At the monitors with producer Rob Molloy. Photo: Brooks Patrick Allen

We start lighting for our “sunset” scene, which involves firing a pink-gelled 6K through the window and netting the background to get some highlight detail into it. Rather than a book light, this time I use a diffused 4×4 Kino Flo as Shirley’s key. I take a risk and place it further off to the side to get a bit more shape into the light.

Shirley enters, takes one glance at the lighting and remarks, “So, you like this cross-light, huh?”

Busted!

We compromise by adding a little fill from a reflector which Shirley positions herself before each take. Her awareness of how she’s being photographed is astounding. She knows more about lighting than some DPs I’ve met!

Looking at the scenes now, I realise that a large white horizontal reflector in front of Shirley would have been perfect to simulate bounce off the bed, which we moved out when we were shooting the close-ups. Hindsight is 20/20, but I’m still pleased with how it turned out.

Next week I’ll break down the huge lighting set-up required for the night exterior circus scenes.

“The Little Mermaid”: Shooting Shirley

6 Tips for Making DIY Lighting Look Pro

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Good lighting can boost the production values of a film tremendously, making the difference between an amateur and a professional-looking piece. For filmmakers early in their careers, however, the equipment typically used to achieve these results can be prohibitively expensive. Far from the Hollywood productions attended by trucks full of lights, a micro-budget film may be unable to rent even a single HMI. Do not despair though, as there are ways to light scenes well without breaking the bank. Here are my top six tips for lighting on the cheap.

 

1. Make the most of natural light

Checking my compass at the stone circle
Guesstimating the sun path on location

The hardest shots to light without the proper equipment are wide shots. Where a fully-budgeted production would rig Maxi Brutes on cherry-pickers, or pound HMIs through windows, a filmmaker of limited means simply won’t have access to the raw power of such fixtures. Instead, plan your day carefully to capture the wide shots at the time when natural light gives you the most assistance. For a day interior, this means shooting when the sun is on the correct side of the building.

See also: “Sun Paths”

 

2. Keep L.E.D.s to the background

£2 LED camping light
£2 LED camping light

There are a plethora of LED fixtures on the market, designed for all kinds of applications, some of them very reasonably priced. It might be tempting to purchase some of these to provide your primary illumination, but I advise against it. Cheap LED units (and fluorescents) have a terrible Colour Rendering Index (CRI), making for unnatural and unappealing skintones. Such units are therefore best restricted to backgrounds, accent lighting and “specials”. For example, I purchased a little LED camping light from a charity shop for about £2, and I often use it to create the blue glow from computer screens or hang it from the ceiling to produce a hint of hair-light.

See also my article on LEDs from my “Know Your Lights” series.

 

3. Key with tungsten or halogen

Worklight
Halogen floodlight

By far the best solution for a high output, high CRI, low cost key is a halogen floodlight; 500W models are available for as little as £5. Their chief disadvantage is the lack of barn doors, making the light hard to control, though if you can stretch to a roll of black wrap you can fashion a kind of snoot. Alternatively, consider investing in a secondhand tungsten movie fixture. With many people switching to LEDs, there are plenty of old tungsten units out there. Try to get a reputable brand like Arri or Ianiro, as some of the unbranded units available on Ebay are poorly wired and can be unsafe.

See also: “DIY Interview Lighting for the ‘Ren’ EPK”

 

4. Control the light

Lace curtains used to break up light in a Camerimage workshop last year

Flooding a halogen light onto a scene is never going to look good, but then the same is often true of dedicated movie fixtures. Instead it’s more how you modify the light that creates the nuanced, professional look. Improvise flags from pieces of cardboard to stop the light spilling into unwanted places – but be VERY careful how close you put them to a tungsten or halogen source, as these get extremely hot. For example, when shooting indoors, flag light off the background wall (especially if it’s white or cream) to help your subject stand out.

See also “Lighting Micro-sets” for an example of this.

 

5. Soften the light

Almost all cinematographers today prefer the subtlety of soft light to the harshness of hard light. You can achieve this by bouncing your fixture off a wall or ceiling, or a sheet of polystyrene or card. Or you could hang a white bedsheet or a shower curtain in front of the light as diffusion, but again be sure to leave a safe distance between them. Professional collapsible reflectors are available very cheaply online, and can be used in multiple ways to diffuse or reflect light.

Hot tub cover = bounce board
Hot tub cover = bounce board. Towel = flag

See also: “How to Soften Harsh Sunlight with Tinfoil and a Bedsheet”; and to read more about the pictured example: “Always Know Where Your Towel Is”

 

6. Make use of practicals

Black-wrapped ceiling light
Black-wrapped ceiling light

Finally, don’t be afraid to use existing practical lighting in your scene. Turning on the main overhead light usually kills the mood, but sometimes it can be useful. You can generate more contrast and shape by covering up the top of the lampshade, thus preventing ceiling bounce, or conversely use the ceiling bounce to give some ambient top-light and cover the bottom of the lampshade to prevent a harsh hotspot underneath it. Table lamps and under-cupboard kitchen lights can add a lot of interest and production value to your backgrounds. If possible, swap out LED or fluorescent bulbs for conventional tungsten ones for a more attractive colour and to eliminate potential flickering on camera.

See also: “5 Tips for Working with Practicals”, and for an example of the above techniques, my blog from day two of the Forever Alone shoot.

6 Tips for Making DIY Lighting Look Pro

What Does “Cinematic” Mean?

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Earlier this year I undertook a personal photography project called Stasis. I deliberately set out to do something different to my cinematography work, shooting in portrait, taking the paintings of Dutch seventeenth century masters as my inspiration, and eschewing traditional lighting fixtures in favour of practical sources. I was therefore a little disappointed when I began showing the images to people and they described them as “cinematic”.

An image from “Stasis”

This experience made me wonder just what people mean by that word, “cinematic”. It’s a term I’ve heard – and used myself – many times during my career. We all seem to have some vague idea of what it means, but few of us are able to define it. 

Dictionaries are not much help either, with the Oxford English Dictionary defining it simply as “relating to the cinema” or “having qualities characteristic of films”. But what exactly are those qualities?

Shallow depth of field is certainly a quality that has been widely described as cinematic. Until the late noughties, shallow focus was the preserve of “proper” movies. The size of a 35mm frame (or of the digital cinema sensors which were then emerging) meant that backgrounds could be thrown way out of focus while the subject remained crisp and sharp. The formats which lower-budget productions had thereto been shot on – 2/3” CCDs and Super-16 film – could not achieve such an effect. 

Then the DSLR revolution happened, putting sensors as big as – or bigger than – those of Hollywood movies into the hands of anyone with a few hundred pounds to spare. Suddenly everyone could get that “cinematic” depth of field. 

My first time utilising the shallow depth of field of a DSLR, on a never-completed feature back in 2011.

Before long, of course, ultra-shallow depth of field became more indicative of a low-budget production trying desperately to look bigger than of something truly cinematic. Gradually young cinematographers started to realise that their idols chose depth of field for storytelling reasons, rather than simply using it because they could. Douglas Slocombe, OBE, BSC, ASC, cinematographer of the original Indiana Jones trilogy, was renowned for his deep depth of field, typically shooting at around T5.6, while Janusz Kaminski, ASC, when shooting Kingdom of the Crystal Skull, stopped down as far as T11.

There was also a time when progressive scan – the recording of discrete frames rather than alternately odd and even horizontal lines to make an interlaced image – was considered cinematic. Now it is standard in most types of production, although deviations from the norm of 24 or 25 frames per second, such as the high frame rate of The Hobbit, still make audiences think of reality TV or news, rejecting it as “uncinematic”.

Other distinctions in shooting style between TV/low-budget film and big-budget film have slipped away too. The grip equipment that enables “cinematic” camera movement – cranes, Steadicams and other stabilisers – is accessible now in some form to most productions. Meanwhile the multi-camera shooting which was once the preserve of TV, looked down upon by filmmakers, has spread into movie production.

A direct comparison may help us drill to the core of what is “cinematic”. Star Trek: Generations, the seventh instalment in the sci-fi film franchise, went into production in spring 1994, immediately after the final TV season of Star Trek: The Next Generation wrapped. The movie shot on the same sets, with the same cast and even the same acquisition format (35mm film) as the TV series. It was directed by David Carson, who had helmed several episodes of the TV series, and whose CV contained no features at that point.

Yet despite all these constants, Star Trek: Generations is more cinematic than the TV series which spawned it. The difference lies with the cinematographer, John A. Alonzo, ASC, one of the few major crew members who had not worked on the TV show, and whose experience was predominantly in features. I suspect he was hired specifically to ensure that Generations looked like a movie, not like TV.

The main thing that stands out to me when comparing the film and the series is the level of contrast in the images. The movie is clearly darker and moodier than the TV show. In fact I can remember my schoolfriend Chris remarking on this at the time – something along the lines of, “Now it’s a movie, they’re in space but they can only afford one 40W bulb to light the ship.” 

The bridge of the Enterprise D as seen on TV (top) and in the “Generations” movie (bottom).

It was a distinction borne of technical limitations. Cathode ray tube TVs could only handle a dynamic range of a few stops, requiring lighting with low contrast ratios, while a projected 35mm print could reproduce much more subtlety. 

Today, film and TV is shot on the same equipment, and both are viewed on a range of devices which are all good at dealing with contrast (at least compared with CRTs). The result is that, with contrast as with depth of field, camera movement and progressive scan, the distinction between the cinematic and the uncinematic has reduced. 

The cinematography of “Better Call Saul” owes much to film noir.

In fact, I’d argue that it’s flipped around. To my eye, many of today’s TV series – and admittedly I’m thinking of high-end ones like The Crown, Better Call Saul or The Man in the High Castle, not Eastenders – look more cinematic than modern movies. 

As my friend Chris had realised, the flat, high-key look of Star Trek: The Next Generation was actually far more realistic than that of its cinema counterpart. And now movies seem to have moved towards realism in the lighting, which is less showy and not so much moody for the sake of being moody, while TV has become more daring and stylised.

A typically moody and contrasty shot from “The Crown”

The Crown, for examples, blasts a 50KW Soft Sun through the window in almost every scene, bathing the monarchy in divine light to match its supposed divine right, while Better Call Saul paints huge swathes of rich, impenetrable black across the screen to represent the rotten soul of its antihero. 

Film lighting today seems to strive for naturalism in the most part. Top DPs like recent Oscar-winner Roger Deakins, CBE, ASC, BSC,  talk about relying heavily on practicals and using fewer movie fixtures, and fellow nominee Rachel Morrison, ASC, despite using a lot of movie fixtures, goes to great lengths to make the result look unlit. Could it be that film DPs feel they can be more subtle in the controlled darkness of a cinema, while TV DPs choose extremes to make their vision clear no matter what device it’s viewed on or how much ambient light contaminates it?

“Mudbound”, shot by Rachel Morrison, ASC

Whatever the reason, contrast does seem to be the key to a cinematic look. Even though that look may no longer be exclusive to movies released in cinemas, the perception of high contrast being linked to production value persists. The high contrast of the practically-lit scenes in my Stasis project is – as best I can tell – what makes people describe it as cinematic.

What does all of this mean for a filmmaker? Simply pumping up the contrast in the grade is not the answer. Contrast should be built into the lighting, and used to reveal and enhance form and depth. The importance of good production design, or at least good locations, should not be overlooked; shooting in a friend’s white-walled flat will kill your contrast and your cinematic look stone dead. 

A shot of mine from “Forever Alone”, a short film where I was struggling to get a cinematic look out of the white-walled location.

Above all, remember that story – and telling that story in the most visually appropriate way – is the essence of cinema. In the end, that is what makes a film truly cinematic.

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What Does “Cinematic” Mean?

The Science of Smoke

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Smoke, haze, atmos, whatever you want to call it, anyone who knows me knows that I’m a big fan. But how does it work and what is the purpose of smoking up a set?

 

Aerial perspective

At the most basic level, smoke simulates a natural phenomenon called aerial perspective. If you look at – for example – a range of mountains receding into the distance, the further mountains will appear bluer, lighter, less contrasty and less colour-saturated than the nearer mountains.

An example of aerial perspective

This effect is due to light being scattered by particles naturally suspended in the air, and by molecules of the air itself. It is described by the scary-looking Rayleigh Equation:

We don’t need to get into what all the variables stand for, but there are a couple of things worth noting:

  • The symbol on the far right represents the angle between the incident light and the scattered light. In practice this means that the more you shoot into the sun – the more the air you’re photographing is backlit – the more scattering there will be. Place the sun behind your camera and scattering will be minimal.
  • Lamda (the sort of upside-down y next to the x) is the wavelength of the light, so the shorter the wavelength, the more scattering. This is why things look bluer with distance: blue light has a shorter wavelength and so is scattered more. It’s also why shooting through an ultraviolet filter reduces the appearance of aerial perspective/atmospheric haze.

 

How smoke works

An Artem smoke gun

Foggers, hazers and smoke machines simulate aerial perspective by adding suspended particles to the air. These particles start off as smoke fluid (a.k.a. “fog juice”) which is made of mineral oil, or of a combination of water and glycol/glycerin.

In a smoke machine or gas-powered smoke gun (like the Artem), smoke fluid is pushed into a heat exchanger which vaporises it. When the vapour makes contact with the colder air, it condenses to form fog.

A hazer uses compression rather than heat to vaporise the fluid, meaning you don’t have to wait for the machine to heat up. The particles are smaller, making for a more subtle and longer-lasting effect.

As a general rule, you should use only hazers for interior cinematography, unless there is a story reason for smoke to be present in the scene. Outdoors, however, hazers are ineffective. An Artem or two will work well for smaller exterior scenes; for larger ones, a Tube of Death is the best solution. This is a long, plastic inflatable tube with regularly-spaced holes, with a fan and a smoke machine (usually electric) at the end. It ensures that smoke is distributed fairly evenly over a large area.

A Tube of Death in action on the set of “The Little Mermaid”

 

The effects of smoke

Just like aerial perspective, smoke/haze separates the background from the foreground, as the background has more smoke between it and the camera. The background becomes brighter, less contrasty, less saturated and (depending on the type of smoke) bluer, making the foreground stand out against it.

Since smoke also obeys the Rayleigh Equation, it shows up best when it’s backlit, a bit when it’s side-lit and barely at all when front-lit.

Here are some of the other things that smoke achieves:

  • It diffuses the image, particularly things further away from camera.
  • It lowers contrast.
  • It brightens the image.
  • It lifts the shadows by scattering light into them.
  • If it’s sufficiently thick, and particularly if it’s smoke rather than haze, it adds movement and texture to the image, which helps to make sets look less fake.
  • It volumises the light, showing up clear shafts of hard light and diffuse pools of soft light. (For more on this, read 5 Tips for Perfect Shafts of Light.)
  • Backlit smoke in front of a person or an object will obscure them, concealing identity.
Heavy smoke (from an Artem) pops Lyanna (Dita Tantang) out of the background in “Ren: The Girl with the Mark” (dir. Kate Madison).
Backlit smoke through a roof of branches creates magical shafts of light in “Ren: The Girl with the Mark”.
The final day/sunset look. From each side an orange-gelled and a pink-gelled par can light the backdrop. A 2K tungsten fresnel provides backlight, while a 650W fresnel with a cucoloris provides dappled light on the tree and tarsier. An LED panel off right supplies fill, and a second panel is inside the cave with a turquoise gel.
The colour-washed infinity cove in the background of this music promo for Lewis Watson’s “Droplets” (dir. Tom Walsh) is softened and disguised by smoke.
Haze gives the LED panels their glowing appearance in this video for “X, Y & Z Rays” (dir. Tom Walsh) by Revenge of Calculon.
This torch beam in “Above the Clouds” (dir. Leon Chambers) shows up so well because the set is heavily fogged.
Smoke backlit by an HMI creates the blue background glow against which the heroes of “The First Musketeer” (dir. Harriet Sams) stand out.
Haze creates the shafts of light from HMIs outside the windows, and adds to the gothic feel of “Heretiks” (dir. Paul Hyett).
The Science of Smoke

The Normal Lens

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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.

Asahi Pentax-M 50mm/f1.4 – a normal lens for 35mm stills

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.

Deleted scene from “Ren: The Girl with the Mark” shot on a vintage 28mm Pentax-M

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.

A scene from “The Little Mermaid” which I shot on a 32mm Cooke S4

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.

The Normal Lens

How Big a Light do I Need?

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Experience goes a long way, but sometimes you need to be more precise about what size of lighting instruments are required for a particular scene. Night exteriors, for example; you don’t want to find out on the day that the HMI you hired as your “moon” backlight isn’t powerful enough to cover the whole of the car park you’re shooting in. How can you prep correctly so that you don’t get egg on your face?

There are two steps: 1. determine the intensity of light you require on the subject, and 2. find a combination of light fixture and fixture-to-subject distance that will provide that intensity.

 

The Required intensity

The goal here is to arrive at a number of foot-candles (fc). Foot-candles are a unit of light intensity, sometimes more formally called illuminance, and one foot-candle is the illuminance produced by a standard candle one foot away. (Illuminance can also be measured in the SI unit of lux, where 1 fc ≈ 10 lux, but in cinematography foot-candles are more commonly used. It’s important to remember that illuminance is a measure of the light incident to a surface, i.e. the amount of light reaching the subject. It is not to be confused with luminance, which is the amount of light reflected from a surface, or with luminous power, a.k.a. luminous flux, which is the total amount of light emitted from a source.)

Usually you start with a T-stop (or f-stop) that you want to shoot at, based on the depth of field you’d like. You also need to know the ISO and shutter interval (usually 1/48th or 1/50th of a second) you’ll be shooting at. Next you need to convert these facets of exposure into an illuminance value, and there are a few different ways of doing this.

One method is to use a light meter, if you have one, which you enter the ISO and shutter values into. Then you wave it around your office, living room or wherever, pressing the trigger until you happen upon a reading which matches your target f-stop. Then you simply switch your meter into foot-candles mode and read off the number. This method can be a bit of a pain in the neck, especially if – like mine – your meter requires fiddly flipping of dip-switches and additional calculations to get a foot-candles reading out of.

A much simpler method is to consult an exposure table, like the one below, or an exposure calculator, which I’m sure is a thing which must exist, but I’ll be damned if I could find one.

Some cinematographers memorise the fact that 100fc is f/2.8 at ISO 100, and work out other values from that. For example, ISO 400 is four times (two stops) faster than ISO 100, so a quarter of the light is required, i.e. 25fc.

Alternatively, you can use the underlying maths of the above methods. This is unlikely to be necessary in the real world, but for the purposes of this blog it’s instructive to go through the process. The equation is:

where

  • b is the illuminance in fc,
  • f is the f– or T-stop,
  • s is the shutter interval in seconds, and
  • i is the ISO.

Say I’m shooting on an Alexa with a Cooke S4 Mini lens. If I have the lens wide open at T2.8, the camera at its native ISO of 800 and the shutter interval at the UK standard of 1/50th (0.02) of a second…

… so I need about 12fc of light.

 

The right instrument

In the rare event that you’re actually lighting your set with candles – as covered in my Barry Lyndon and Stasis posts – then an illuminance value in fc is all you need. In every other situation, though, you need to figure out which electric light fixtures are going to give you the illuminance you need.

Manufacturers of professional lighting instruments make this quite easy for you, as they all provide data on the illuminance supplied by their products at various distances. For example, if I visit Mole Richardson’s webpage for their 1K Baby-Baby fresnel, I can click on the Performance Data table to see that this fixture will give me the 12fc (in fact slightly more, 15fc) that I required in my Alexa/Cooke example at a distance of 30ft on full flood.

Other manufacturers provide interactive calculators: on ETC’s site you can drag a virtual Source Four back and forth and watch the illuminance read-out change, while Arri offers a free iOS/Android app with similar functionality.

If you need to calculate an illuminance value for a distance not specified by the manufacturer, you can derive it from distances they do specify, by using the Inverse Square Law. However, as I found in my investigatory post about the law, that could be a whole can of worms.

If illuminance data is not available for your light source, then I’m afraid more maths is involved. For example, the room I’m currently in is lit by a bulb that came in a box marked “1,650 lumens”, which is the luminous power. One lumen is one foot-candle per square foot. To find out the illuminance, i.e. how many square feet those lumens are spread over, we imagine those square feet as the area of a sphere with the lamp at the centre, and where the radius r is the distance from the lamp to the subject. So:

where

  • b is again the illuminance in fc,
  • p is the luminous power of the souce in lumens, and
  • r is the lamp-to-subject distance in feet.

(I apologise for the mix of Imperial and SI units, but this is the reality in the semi-Americanised world of British film production! Also, please note that this equation is for point sources, rather than beams of light like you get from most professional fixtures. See this article on LED Watcher if you really want to get into the detail of that.)

So if I want to shoot that 12fc scene on my Alexa and Cooke S4 Mini under my 1,650 lumen domestic bulb…

… my subject needs to be 3’4″ from the lamp. I whipped out my light meter to check this, and it gave me the target T2.8 at 3’1″ – pretty close!

 

Do I have enough light?

If you’re on a tight budget, it may be less a case of, “What T-stop would I like to shoot at, and what fixture does that require?” and more a case of, “Is the fixture which I can afford bright enough?”

Let’s take a real example from Perplexed Music, a short film I lensed last year. We were shooting on an Alexa at ISO 1600, 1/50th sec shutter, and on Arri/Zeiss Ultra Primes, which have a maximum aperture of T1.9. The largest fixture we had was a 2.5K HMI, and I wanted to be sure that we would have enough light for a couple of night exteriors at a house location.

In reality I turned to an exposure table to find the necessary illuminance, but let’s do the maths using the first equation that we met in this post:

Loading up Arri’s photometrics app, I could see that 2.8fc wasn’t going to be a problem at all, with the 2.5K providing 5fc at the app’s maximum distance of 164ft.

That’s enough for today. All that maths may seem bewildering, but most of it is eliminated by apps and other online calculators in most scenarios, and it’s definitely worth going to the trouble of checking you have enough light before you’re on set with everyone ready to roll!

See also: 6 Ways of Judging Exposure

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How Big a Light do I Need?

“The Knowledge”: Lighting a Multi-camera Game Show

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Metering the key-light. Photo: Laura Radford

Last week I discussed the technical and creative decisions that went into the camerawork of The Knowledge, a fake game show for an art installation conceived by Ian Wolter and directed by Jonnie Howard. This week I’ll break down the choices and challenges involved in lighting the film.

The eighties quiz shows which I looked at during prep were all lit with the dullest, flattest light imaginable. It was only when I moved forward to the nineties shows which Jonnie and I grew up on, like Blockbusters and The Generation Game, that I started to see some creativity in the lighting design: strip-lights and glowing panels in the sets, spotlights and gobos on the backgrounds, and moodier lighting states for quick-fire rounds.

Jonnie and I both wanted The Knowledge‘s lighting to be closer to this nineties look. He was keen to give each team a glowing taxi sign on their desks, which would be the only source of illumination on the contestants at certain moments. Designer Amanda Stekly and I came up with plans for additional practicals – ultimately LED string-lights – that would follow the map-like lines in the set’s back walls.

Once the set design had been finalised, I did my own dodgy pencil sketch and Photoshopped it to create two different lighting previsualisations for Jonnie.

He felt that these were a little too sophisticated, so after some discussion I produced a revised previz…

…and a secondary version showing a lighting state with one team in shadow.

These were approved, so now it was a case of turning those images into reality.

We were shooting on a soundstage, but for budget reasons we opted not to use the lighting grid. I must admit that this worried me for a little while. The key-light needed to come from the front, contrary to normal principles of good cinematography, but very much in keeping with how TV game shows are lit. I was concerned that the light stands and the cameras would get in each others’ way, but my gaffer Ben Millar assured me it could be done, and of course he was right.

Ben ordered several five-section Strato Safe stands (or Fuck-offs as they’re charmingly known). These were so high that, even when placed far enough back to leave room for the cameras, we could get the 45° key angle which we needed in order to avoid seeing the contestants’ shadows on the back walls. (A steep key like this is sometimes known as a butterfly key, for the shape of the shadow which the subject’s nose casts on their upper lip.)  Using the barn doors, and double nets on friction arms in front of the lamp-heads, Ben feathered the key-light to hit as little as possible of the back walls and the fronts of the desks. As well as giving the light some shape, this prevented the practical LEDs from getting washed out.

Note the nets mounted below the key-lights (the tallest ones). Photo: Laura Radford

Once those key-lights were established (a 5K fresnel for each team), we set a 2K backlight for each team as well. These were immediately behind the set, their stands wrapped in duvetyne, and the necks well and truly broken to give a very toppy backlight. A third 2K was placed between the staggered central panels of the set, spilling a streak of light out through the gap from which host Robert Jezek would emerge.

A trio of Source Fours with 15-30mm zoom lenses were used for targeted illumination of certain areas. One was aimed at The Knowledge sign, its cutters adjusted to form a rectangle of light around it. Another was focused on the oval map on the floor, which would come into play during the latter part of the show. The last Source Four was used as a follow-spot on Robert. We had to dim it considerably to keep the exposure in range, which conveniently made him look like he had a fake tan! Ben hooked everything, in fact, up to a dimmer board, so that various lighting cues could be accomplished in camera.

The bulk of the film was recorded in a single day, following a day’s set assembly and a day of pre-rigging. A skeleton crew returned the next day to shoot pick-ups and promos, a couple of which you can see on Vimeo here.

I’ll leave you with some frame grabs from the finished film. Find out more about Ian Wolter’s work at ianwolter.com.

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“The Knowledge”: Lighting a Multi-camera Game Show

“The Knowledge”: Shooting a Multi-camera Game Show

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Robert Jezek as gameshow host Robert O’Reilly. Photo: Laura Radford

Last week saw the UK premier of The Knowledge, an art installation film, at the FLUX Exhibition hosted by Chelsea College of Arts. Conceived by award-winning, multi-disciplinary artist Ian Wolter, The Knowledge comments on the topical issue of artificial intelligence threatening jobs. It takes the form of a fake game show, pitting a team of traditional London cabbies (schooled in the titular Knowledge) against a team of smart-phoning minicab drivers. Although shot entirely on stage, the film’s central conceit is that the teams are each guiding a driver across London, to see whether technology or human experience will bring its car to the finish line first.

You can see a couple of brief promos on Vimeo here. It’s a unique project, and one that I knew would be an interesting challenge as soon as I heard of it from my friend Amanda Stekly, producer and production designer. This week and next I’ll describe the creative and technical decisions that went into photographing the piece, beginning this week with the camera side of things.

Photo: Laura Radford

I had never shot a multi-camera studio production like this before, so my first move was to sit down with my regular 1st AC and steadicam operator Rupert Peddle, and his friend Jackie D’Souza-Toulson. Jackie has extensive experience operating as part of a multi-camera team for live TV and events. This conversation answered such basic questions as, could the operators each pull their own focus? (yes) and allowed me to form the beginnings of a plan for crew and kit.

At the monitors with Jonnie. Photo: Laura Howard

Ian and Amanda wanted the film to have a dated look, and referenced such eighties quiz shows as 3-2-1 and Blankety Blank. Director Jonnie Howard and I knew that we had to supply the finished film in HD, which ruled out shooting on vintage analogue video cameras. Interlaced recording was rejected for similar reasons, though if memory serves, I did end up shooting at a shutter angle of 360 degrees to produce a more fluid motion suggestive of interlaced material.

I was very keen that the images should NOT look cinematic. Jonnie was able to supply two Canon C100s – which I’ve always thought have a sharp, “video-ish” look – and L-series glass. I set these to 1600 ISO to give us the biggest possible depth of field. For the remaining two cameras, I chose ENG models, a Canon XF-300 (owned by Rupert) and XF-305. In an ideal world, all four cameras would have been ENG models, to ensure huge depth of field and an overall TV look, but some compromise was necessary for budget reasons, and at least they all used Canon sensors. We hired a rack of four matching 9″ monitors so we could ensure a consistent look on set.

Photo: Laura Radford

One Canon C100, with an L-series zoom, was mounted on a pedestal and outfitted with Rupert’s follow focus system, allowing Jackie to pull focus from the panning handle. The other C100 would shoot a locked-off wide, and was the first camera to be set up. A 14mm Samyang lens made the set look huge, and I placed it low down to emphasise the map in the foreground, and to make it easy for the other cameras to shoot over it. Once that frame was set, we taped a large V shape on the floor to indicate the edges of the wide shot. As long as the lights and other cameras stayed out of that area, they would be safe.

Jackie operates the pedestal-mounted C100. Photo: Laura Radford

Generally Jackie’s pedestal-mounted C100 followed the host, Robert Jezek, or captured the interesting moving shots, while Rupert and the third operator, Jimmy Buchanan, cross-shot the two teams on the XF-100 and XF-105. No filtration was used, except for a four-point star filter on one camera when glitter canons are fired at the end of the game. This cheesiness was inspired by the 3-2-1 clips I watched for research, in which star filters were used for the tacky sequences showing the prizes on offer.

Next week I’ll discuss lighting the show. Meanwhile, find out more about Ian’s work at ianwolter.com.

Photo: Laura Radford

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“The Knowledge”: Shooting a Multi-camera Game Show

Colour Schemes

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Last week I looked at the science of colour: what it is, how our eyes see it, and how cameras see and process it. Now I’m going to look at colour theory – that is, schemes of mixing colours to produce aesthetically pleasing results.

 

The Colour wheel

The first colour wheel was drawn by Sir Isaac Newton in 1704, and it’s a precursor of the CIE diagram we met last week. It’s a method of arranging hues so that useful relationships between them – like primaries and secondaries, and the schemes we’ll cover below – can be understood. As we know from last week, colour is in reality a linear spectrum which we humans perceive by deducing it from the amounts of light triggering our red, green and blue cones, but certain quirks of our visual system make a wheel in many ways a more useful arrangement of the colours than a linear spectrum.

One of these quirks is that our long (red) cones, although having peak sensitivity to red light, have a smaller peak in sensitivity at the opposite (violet) end of the spectrum. This may be what causes our perception of colour to “wrap around”.

Another quirk is in the way that colour information is encoded in the retina before being piped along the optic nerve to the brain. Rather than producing red, green and blue signals, the retina compares the levels of red to green, and of blue to yellow (the sum of red and green cones), and sends these colour opponency channels along with a luminance channel to the brain.

You can test these opposites yourself by staring at a solid block of one of the colours for around 30 seconds and then looking at something white. The white will initially take on the opposing colour, so if you stared at red then you will see green.

Hering’s colour wheels

19th century physiologist Ewald Hering was the first to theorise about this colour opponency, and he designed his own colour wheel to match it, having red/green on the vertical axis and blue/yellow on the horizontal.

RGB colour wheel

Today we are more familiar with the RGB colour wheel, which spaces red, green and blue equally around the circle. But both wheels – the first dealing with colour perception in the eye-brain system, and the second dealing with colour representation on an RGB screen – are relevant to cinematography.

On both wheels, colours directly opposite each other are considered to cancel each other out. (In RGB they make white when combined.) These pairs are known as complementary colours.

 

Complementary

A complementary scheme provides maximum colour contrast, each of the two hues making the other more vibrant. Take “The Snail” by modernist French artist Henri Matisse, which you can currently see at the Tate Modern; Matisse placed complementary colours next to each other to make them all pop.

“The Snail” by Henri Matisse (1953)

In cinematography, a single pair of complementary colours is often used, for example the yellows and blues of Aliens‘ power loader scene:

“Aliens” DP: Adrian Biddle, BSC

Or this scene from Life on Mars which I covered on my YouTube show Lighting I Like:

I frequently use a blue/orange colour scheme, because it’s the natural result of mixing tungsten with cool daylight or “moonlight”.

“The First Musketeer”, DP: Neil Oseman

And then of course there’s the orange-and-teal grading so common in Hollywood:

“Hot Tub Time Machine” DP: Jack N. Green, ASC

Amélie uses a less common complementary pairing of red and green:

“Amélie” DP: Bruno Belbonnel, AFC, ASC

 

Analogous

An analogous colour scheme uses hues adjacent to each other on the wheel. It lacks the punch and vibrancy of a complementary scheme, instead having a harmonious, unifying effect. In the examples below it seems to enhance the single-mindedness of the characters. Sometimes filmmakers push analogous colours to the extreme of using literally just one hue, at which point it is technically monochrome.

“The Matrix” DP: Bill Pope, ASC
“Terminator 2: Judgment Day” DP: Adam Greenberg, ASC
“The Double” DP: Erik Alexander Wilson
“Total Recall” (1990) DP: Jost Vacano, ASC, BVK

 

There are other colour schemes, such as triadic, but complementary and analogous colours are by far the most common in cinematography. In a future post I’ll look at the psychological effects of individual colours and how they can be used to enhance the themes and emotions of a film.

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Colour Schemes

How Colour Works

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Colour is a powerful thing. It can identify a brand, imply eco-friendliness, gender a toy, raise our blood pressure, calm us down. But what exactly is colour? How and why do we see it? And how do cameras record it? Let’s find out.

 

The Meaning of “Light”

One of the many weird and wonderful phenomena of our universe is the electromagnetic wave, an electric and magnetic oscillation which travels at 186,000 miles per second. Like all waves, EM radiation has the inversely-proportional properties of wavelength and frequency, and we humans have devised different names for it based on these properties.

The electromagnetic spectrum

EM waves with a low frequency and therefore a long wavelength are known as radio waves or, slightly higher in frequency, microwaves; we used them to broadcast information and heat ready-meals. EM waves with a high frequency and a short wavelength are known as x-rays and gamma rays; we use them to see inside people and treat cancer.

In the middle of the electromagnetic spectrum, sandwiched between infrared and ultraviolet, is a range of frequencies between 430 and 750 terahertz (wavelengths 400-700 nanometres). We call these frequencies “light”, and they are the frequencies which the receptors in our eyes can detect.

If your retinae were instead sensitive to electromagnetic radiation of between 88 and 91 megahertz, you would be able to see BBC Radio 2. I’m not talking about magically seeing into Ken Bruce’s studio, but perceiving the FM radio waves which are encoded with his silky-smooth Scottish brogue. Since radio waves can pass through solid objects though, perceiving them would not help you to understand your environment much, whereas light waves are absorbed or reflected by most solid objects, and pass through most non-solid objects, making them perfect for building a picture of the world around you.

Within the range of human vision, we have subdivided and named smaller ranges of frequencies. For example, we describe light of about 590-620nm as “orange”, and below about 450nm as “violet”. This is all colour really is: a small range of wavelengths (or frequencies) of electromagnetic radiation, or a combination of them.

 

In the eye of the beholder

Scanning electron micrograph of a retina

The inside rear surfaces of your eyeballs are coated with light-sensitive cells called rods and cones, named for their shapes.

The human eye has about five or six million cones. They come in three types: short, medium and long, referring to the wavelengths to which they are sensitive. Short cones have peak sensitivity at about 420nm, medium at 530nm and long at 560nm, roughly what we call blue, green and red respectively. The ratios of the three cone types vary from person to person, but short (blue) ones are always in the minority.

Rods are far more numerous – about 90 million per eye – and around a hundred times more sensitive than cones. (You can think of your eyes as having dual native ISOs like a Panasonic Varicam, with your rods having an ISO six or seven stops faster than your cones.) The trade-off is that they are less temporally and spatially accurate than cones, making it harder to see detail and fast movement with rods. However, rods only really come into play in dark conditions. Because there is just one type of rod, we cannot distinguish colours in low light, and because rods are most sensitive to wavelengths of 500nm, cyan shades appear brightest. That’s why cinematographers have been painting night scenes with everything from steel grey to candy blue light since the advent of colour film.

The spectral sensitivity of short (blue), medium (green) and long (red) cones

The three types of cone are what allow us – in well-lit conditions – to have colour vision. This trichromatic vision is not universal, however. Many animals have tetrachromatic (four channel) vision, and research has discovered some rare humans with it too. On the other hand, some animals, and “colour-blind” humans, are dichromats, having only two types of cone in their retinae. But in most people, perceptions of colour result from combinations of red, green and blue. A combination of red and blue light, for example, appears as magenta. All three of the primaries together make white.

Compared with the hair cells in the cochlea of your ears, which are capable of sensing a continuous spectrum of audio frequencies, trichromacy is quite a crude system, and it can be fooled. If your red and green cones are triggered equally, for example, you have no way of telling whether you are seeing a combination of red and green light, or pure yellow light, which falls between red and green in the spectrum. Both will appear yellow to you, but only one really is. That’s like being unable to hear the difference between, say, the note D and a combination of the notes C and E. (For more info on these colour metamers and how they can cause problems with certain types of lighting, check out Phil Rhode’s excellent article on Red Shark News.)

 

Artificial eye

A Bayer filter

Mimicking your eyes, video sensors also use a trichromatic system. This is convenient because it means that although a camera and TV can’t record or display yellow, for example, they can produce a mix of red and green which, as we’ve just established, is indistinguishable from yellow to the human eye.

Rather than using three different types of receptor, each sensitive to different frequencies of light, electronic sensors all rely on separating different wavelengths of light before they hit the receptors. The most common method is a colour filter array (CFA) placed immediately over the photosites, and the most common type of CFA is the Bayer filter, patented in 1976 by an Eastman Kodak employee named Dr Bryce Bayer.

The Bayer filter is a colour mosaic which allows only green light through to 50% of the photosites, only red light through to 25%, and only blue to the remaining 25%. The logic is that green is the colour your eyes are most sensitive to overall, and that your vision is much more dependent on luminance than chrominance.

A RAW, non-debayered image

The resulting image must be debayered (or more generally, demosaiced) by an algorithm to produce a viewable image. If you’re recording log or linear then this happens in-camera, whereas if you’re shooting RAW it must be done in post.

This system has implications for resolution. Let’s say your sensor is 2880×1620. You might think that’s the number of pixels, but strictly speaking it isn’t. It’s the number of photosites, and due to the Bayer filter no single one of those photosites has more than a third of the necessary colour information to form a pixel of the final image. Calculating that final image – by debayering the RAW data – reduces the real resolution of the image by 20-33%. That’s why cameras like the Arri Alexa or the Blackmagic Cinema Camera shoot at 2.8K or 2.5K, because once it’s debayered you’re left with an image of 2K (cinema standard) resolution.

 

colour Compression

Your optic nerve can only transmit about one percent of the information captured by the retina, so a huge amount of data compression is carried out within the eye. Similarly, video data from an electronic sensor is usually compressed, be it within the camera or afterwards. Luminance information is often prioritised over chrominance during compression.

Examples of chroma subsampling ratios

You have probably come across chroma subsampling expressed as, for example, 444 or 422, as in ProRes 4444 (the final 4 being transparency information, only relevant to files generated in postproduction) and ProRes 422. The three digits describe the ratios of colour and luminance information: a file with 444 chroma subsampling has no colour compression; a 422 file retains colour information only in every second pixel; a 420 file, such as those on a DVD or BluRay, contains one pixel of blue info and one of red info (the green being derived from those two and the luminance) to every four pixels of luma.

Whether every pixel, or only a fraction of them, has colour information, the precision of that colour info can vary. This is known as bit depth or colour depth. The more bits allocated to describing the colour of each pixel (or group of pixels), the more precise the colours of the image will be. DSLRs typically record video in 24-bit colour, more commonly described as 8bpc or 8 bits per (colour) channel. Images of this bit depth fall apart pretty quickly when you try to grade them. Professional cinema cameras record 10 or 12 bits per channel, which is much more flexible in postproduction.

CIE diagram showing the gamuts of three video standards. D65 is the standard for white.

The third attribute of recorded colour is gamut, the breadth of the spectrum of colours. You may have seen a CIE (Commission Internationale de l’Eclairage) diagram, which depicts the range of colours perceptible by human vision. Triangles are often superimposed on this diagram to illustrate the gamut (range of colours) that can be described by various colour spaces. The three colour spaces you are most likely to come across are, in ascending order of gamut size: Rec.709, an old standard that is still used by many monitors; P3, used by digital cinema projectors; and Rec.2020. The latter is the standard for ultra-HD, and Netflix are already requiring that some of their shows are delivered in it, even though monitors capable of displaying Rec.2020 do not yet exist. Most cinema cameras today can record images in Rec.709 (known as “video” mode on Blackmagic cameras) or a proprietary wide gamut (“film” mode on a Blackmagic, or “log” on others) which allows more flexibility in the grading suite. Note that the two modes also alter the recording of luminance and dynamic range.

To summarise as simply as possible: chroma subsampling is the proportion of pixels which have colour information, bit depth is the accuracy of that information and gamut is the limits of that info.

That’s all for today. In future posts I will look at how some of the above science leads to colour theory and how cinematographers can make practical use of it.

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How Colour Works