Know Your Lamps: Overview

Welcome to the first in a series of posts looking at the many types of lighting instruments in use on film and TV sets today. This is not intended to be an exhaustive or comprehensive list, but it will give you a good idea of your options, particularly if you’re moving up from smaller productions – where lighting kit is mostly borrowed – to larger ones, where you’re required to submit a lighting list to a rental house.

Some of the key considerations when choosing a lamp are:

  • Colour temperature – how orange or blue the light appears – see this post for more info
  • CRI – Colour Rendering Index – how full a spectrum of light is emitted, and therefore how accurately colours are rendered
  • Light quality – how hard or soft the light is
  • Power consumption
  • Hire cost

Lamps can be divided into categories according to the means by which they produce light. Here is an overview of the main types.

 

Redheads draw 800W each

Incandescent (view detailed post)

Incandescent lamps work by passing electrical current through a wire filament which becomes so hot that it glows. In the film industry they are generally referred to as ‘tungsten‘ units after the metal which the filament is made from. Common tungsten lamps include Dedolites, 1K ‘babies’ and open-face 800W and 2KW units (which have misogynous nicknames I shall not repeat here).

Pros: cheap, dimmable, extremely high CRI

Cons: very inefficient, get very hot, colour temperature changes when dimmed

Colour temperature: 3,200K

Light quality: generally hard (although certain units like Space Lights are softer)

 

HMI fresnel

HMI (view detailed post)

The HMI (hydragyrum medium-arc iodide) is the most common form of high intensity discharge lamp used in the industry. It operates by creating an electrical arc between two electrodes which excites a gas. You may occasionally hear about an MSR (medium source rare-earth), which is slightly different technology, but as far as a cinematographer is concerned MSRs and HMIs are the same. They require a ballast to ignite the arc and regulate the current and voltage.

Pros: good CRI, good match for daylight, efficient

Cons: only dimmable down to 50%, expensive, heads and ballasts sometimes hum or ‘squeal’, older bulbs can vary in colour, flicker issues at certain shutter angles with magnetic ballasts

Colour temperature: 5,600K

Light quality: hard

 

Kino4x4Fluorescent (view detailed post)

Fluorescent lamps are found almost everywhere today, as strip lights in supermarkets and offices, and energy-saver bulbs in the home. Similar in principle to HMIs, electric current causes mercury vapour to emit UV light which is translated into the visible spectrum by the phosphor coating on the tube. Kino Flo pretty much has the monopoly on fluorescent lighting for the film industry. Like HMIs, fluorescents require a ballast.

Pros: reasonable CRI from Kino Flos (appalling CRI from domestic/commercial fixtures), very efficient, get warm but not hot

Cons: limited dimming, high fall-off of light

Colour temperature: 5,500K and 3,200K tubes available

Light quality: soft

 

LED copyLED (view detailed post)

Gradually replacing tungsten as the most common lamps found on no-budget shoots, LED (light emitting diode) units contain semi-conductors that emit light when their electrons reconfigure. The technology is advancing rapidly, but there is currently a wide range of LED lamps on the market, varying greatly in price and corresponding quality.

Pros: extremely efficient, barely get warm, can run off batteries, almost fully dimmable, some models have adjustable colour temperature

Cons: CRI ranges from almost acceptable in the expensive models to downright shocking in the cheaper ones

Colour temperature: varies

Light quality: varies

 

Though there are other types of lighting, like xenon, metal-halide and HEP (high efficiency plasma), the above four are the main ones you will encounter on film and TV sets today. Over the next few weeks I’ll look at each of those types in more detail, listing many of the specific units available in each category and their applications.

By the way, if your budget is too tight to hire film lamps of any kind, you may want to check out my post on lighting without movie lamps.

Know Your Lamps: Overview

5 Tips for Lighting a Green Screen

Green screen work is almost unavoidable for a modern cinematographer. In an age when even the most basic of corporates might use the technique, and big blockbusters might never leave the green screen stage, knowing how to light for it is essential. The following tips apply equally to blue screen work….

IMG_0837 1. Light the screen at key.

Or to put it another way, your screen should not be over- or under-exposed. If you use a light meter, you can hold it at various spots on the screen (taking care not to block any light with your body) and check that the reading always matches what the iris of your lens is set to. If your camera or monitor has a false colours option, you can use this to check the level and consistency of the exposure across the screen.

2. Use soft sources.

Bouncing tungsten lamps off polyboard is a cheap and effective way to spread soft light across a green screen. Typically you will want two sources, one to each side of the screen. They will need to be well flagged so that their light does not spill onto the subject.

On larger budgets, Kinoflo Image 85s or 87s are often used to illuminate green screens. They are 4ft 8-bank units which put out a large amount of soft light. Ask your hire company to supply them with spiked green tubes; designed especially for green screen work, these tubes help to increase the colour saturation of the screen. (Spiked blue tubes are also available.)

3. Control spill.

As far as possible, reflected green light from the screen should not fall on the subject. The main way to ensure this is to put as much distance as possible between the screen and the subject.

I learnt a great tip recently which also helps reduce spill: once the exact camera position is known, bring in 4×4 floppy flags slightly behind the subject, one either side, just out of frame.

IMG_31674. Avoid dark shadows.

Green spill will bleed most easily into the dark areas on your subject, especially if you’re shooting with a wide aperture. Clipped (or ‘crushed’) blacks are particularly undesirable. The solution is to use more fill light, even if this goes against the mood and contrast levels you’re using in non-VFX shots. If you use LUTs, you should consider creating a custom one for green screen work which pushes the contrast further to compensate for this flatter starting point. If not, you will have to work with the colourist in post to ensure that the shadows are restored to their usual levels once the VFX are complete.

5. Add tracking markers.

Camera movement against green screen isn’t the no-no that it used to be, with any VFX team worth their salt being able to deal with handheld shots, pans, tilts and push-ins. If there isn’t a VFX supervisor on set, you can help them out by taping crosses to a few points on the screen. There should always be at least one marker in shot throughout the camera move (more if it’s a multi-axis move), and they shouldn’t stay put behind any tricky edges (e.g. long hair) for long.

5 Tips for Lighting a Green Screen

Looking Back: Daemos Rising

Who is that handsome young chap?Last month saw the re-release of Reeltime Pictures‘ Daemos Rising, an unofficial Doctor Who spin-off film I photographed way back in 2003. It’s lovely to know that the film is popular enough for a high street release after so much time, and watching it again brought back many memories. Let the sharing of these memories commence…

2003 was Doctor Who’s 40th anniversary year, but the show had been off the air for over a decade and many fans, myself included, thought it would never return. In September I was weeks away from the start of principal photography on my second (and last) no-budget feature, Soul Searcher, but I was delighted to take a break from the stresses of self-producing to DP a tribute to the show I’d grown up with. “You won’t hear anything more from me now for a week,” I announced on my Soul Searcher blog on September 16th, “for I shall be ensconced in a cottage in a woodland area of Dorset (or possibly Devon – they’re easily confused), shooting a Doctor Who spin-off film for Reeltime Pictures. As you do.”

Screen Shot 2016-08-13 at 14.59.00The location was in fact in Devon: the home of Ian Richardson, who has since sadly passed away. (Ian had an illustrious stage and screen career, including the lead role in the original UK version of House of Cards.) Although Ian’s involvement would be limited to a voiceover, his son Miles Richardson played the role of Douglas Cavendish, an ex-UNIT operative troubled by a time-travelling ghost, a creepy moving statue and of course the Daemons. For those non-Whoovers amongst you, the Daemons are a devilish alien race featured in a classic Third Doctor serial. Reaching its tentacles deep into the expanded Who-niverse, Daemos Rising was also a sequel to a prior Reeltime production, Downtime, and was tied in to a spin-off book series.

Screen Shot 2016-08-13 at 15.16.32It was Miles who recommended me to director Keith Barnfather, having worked with me earlier that year on a feature called Blood Relative. Miles was joined on screen by his wife Beverley Cressman, playing Brigadier Lethbridge-Stewart’s daughter Kate. Rounding out the cast of three, as the aforementioned spectre, was Andrew Wisher, whose father Michael was the very first (and arguably best) actor to portray Dalek creator Davros.

The shoot didn’t start well. On the journey down to Devon, the prop shaft (bit that connects the engine to the wheels) dropped out of our rental van on the M5! Luis, the driver miraculously got us onto the hard shoulder while we still had some momentum, and the DVD extras include footage of us recovering as we awaited the RAC.

But this brush with death aside, I remember the shoot as a very happy one. It was a small team, just the three actors, Keith, his partner Anastasia, writer David J. Howe and his wife Rosie, and Luis on sound. We all stayed at the cottage, which was lovely, and enjoyed many a home-cooked meal and showbiz yarn. Miles and Andrew even gave an impromptu rendition of Billy Joel’s a cappella classic The Longest Time at one point.

Screen Shot 2016-08-13 at 14.57.17

It was the era of Mini-DV, so I was shooting on my Canon XL1-S in glorious 576i. (I remember the damp playing havoc with the DV tapes when we shot the third act in a cave system called Kent’s Cavern.) I also supplied the lighting package, which consisted of 2 x 800W Arrilites, 2 x 1000W Arrilites and a vintage 5K Mole Richardson fresnel. The latter required a local electrician to wire us a 32A socket into Ian’s fusebox! Back then I used only hard light because I didn’t know any better, and it gave everything a distinctive noir style.

Screen Shot 2016-08-13 at 15.15.26 (2)Speaking of a distinctive style, Daemos Rising is a significant milestone in my career because it was the first time I ever used smoke. The script called for spooky mist in several scenes, so Keith bought a Magnum 550 and we ended up using it on all the night exteriors. He kindly gifted me the machine at the end of the shoot, and needless to say I never looked back. Many a cast and crew may think of their poor lungs and rue the day that Keith Barnfather gave Neil Oseman his first smoke machine!

While the day interior lighting looks rough to me now, I think many of the night scenes still look pretty good 13 years on. Although my lamps were all tungsten, and the XL1 didn’t allow me to dial in a white balance, I would point the camera at something red and force the camera to white-balance on that, turning everything a nice James Cameron cyan.

Screen Shot 2016-08-13 at 15.01.20Just days after we wrapped, the BBC announced that Doctor Who would return in 2005. I fear the new generation of kids who now form the core of Who’s avid audience might find Daemos Rising a little slow and talky, but for fans of the classic series there is lots to enjoy. The tone and storyline are very Who, and there are several easter eggs scattered throughout the film. And some aspects of Daemos Rising fit the new series’ continuity too, including the Brigadier’s daughter Kate — now played by Jemma Redgrave – and UNIT’s Black Archive.

The re-release provides the opportunity to watch Daemos Rising in the aspect ratio we originally intended, 16:9 (the original DVD having been masked only to 14:9) and also offers the option of 5.1 surround sound. It’s available now from Amazon and high street retailers.

Looking Back: Daemos Rising

Lighting in Traditional Art

IMG_0879As I dig deeper into the craft of cinematography I feel the need to consume more references and inspiration than cinema itself can provide. To that end, I took a trip this week to the National Portrait Gallery in Trafalgar Square to see a little of  how light has been used in painting and photography over the last few centuries.

The light in many of the portraits is strikingly similar, with the subjects positioned near an unseen window in such a way as to light their up-side, the side of their face closest to the artist or viewer. This is known as a broad key, and in modern cinematography you don’t see it very often; a short key (‘lighting the down-side’) is almost universally favoured. The only convincing explanation I can offer for this is changing fashions.

The paintings that caught my eye were the ones that try something a little different with their lighting. I found it an interesting exercise to work out where the natural light was coming from and how I would recreate it with modern equipment. Here are three of my favourites…

 

Frederick, Duke of York and Albany by Sir David Wilkie (1823)

by Sir David Wilkie, oil on panel, 1822-1823, dated 1823

Rather than using the daylight to illuminate his subject’s face, Wilkie seats the duke with his back to the window, which cross-lights his sword nicely. The paper in his hand acts as a bounce board, throwing light back onto his face and shirt buttons. It’s great fun doing this in cinematography – firing a hot source in through a window and then seeing it bounce unpredictably off the set and costumes. If I was recreating this painting, the source might be a 6K HMI through a diffusion frame.

 

Thomas Henry Huxley by John Collier (1883)

NPG 3168; Thomas Henry Huxley by John Collier

I love how the top-light in this painting throws Huxley’s eye sockets into shadow, making him resemble the skull he’s holding. I’m guessing Collier didn’t pitch the portrait that way though! I might recreate this using a lightly diffused Joker Bug rigged to the ceiling, or a Source 4 Leiko fired up into an overhead bounce board.

 

The Mission of Mercy: Florence Nightingale Receiving the Wounded at Scutari by Jerry Barrett (1857)

NPG 6202; The Mission of Mercy: Florence Nightingale receiving the Wounded at Scutari by Jerry Barrett

The key light here is coming from the left – perhaps a 12K through a 12×12 full grid – but there’s a hotter shaft picking out Flo in the centre. For that I might use a 2.5K just out of frame, flagged to hit only her. At her feet there would have to be a silver reflector to kick that up-light onto the face of the kneeling woman. The characters on the right of frame are edged quite strongly by the light from the archway. (We know from looking at the shadows on the background buildings that it can’t be direct sunlight, so there must be a window or a very bright wall which that edge light is bouncing off.) I would use an 8×4 matte silver bounce board or maybe even a mirror board to recreate that.

That’s all for now, but look out for more art posts in the near future.

Lighting in Traditional Art