# How is Dynamic Range Measured?

Recently I’ve been pondering which camera to shoot an upcoming project on, so I consulted the ASC’s comparison chart. Amongst the many specs compared is dynamic range, and I noticed that the ARRI Alexa’s was given as 14+ stops, while the Blackmagic URSA’s is 15. Having used both cameras a fair bit, I can tell you that there’s no way in Hell that the Ursa has a higher dynamic range than the Alexa. So what’s going on here?

### What is dynamic range?

To put it simply, dynamic range is the level of contrast that an imaging system can handle. To quote Alan Roberts, who we’ll come back to later:

This is normally calculated as the ratio of the exposure which just causes white clipping to the exposure level below which no details can be seen.

A photosite on a digital camera’s sensor outputs a voltage proportional to the amount of light hitting it, but at some point the voltage reaches a maximum, and no matter how much more light you add, it won’t change. At the other end of the scale, a photosite may receive so little light that it outputs no voltage, or at least nothing that’s discernible from the inherent electronic noise in the system. These upper and lower limits of brightness may be narrowed by image processing within the camera, with RAW recording usually retaining the full dynamic range, while linear Rec. 709 severely curtails it.

In photography and cinematography, we measure dynamic range in stops – doublings and halvings of light which I explain fully in this article. One stop is a ratio of 2:1, five stops are 32:1, thirteen stops are almost 10,000:1

It’s worth pausing here to point out the difference between dynamic range and latitude, a term which is sometimes regarded as synonymous, but it’s not. The latitude is a measure of how much the camera can be over- or under-exposed without losing any detail, and is dependent on both the dynamic range of the camera and the dynamic range of the scene. (A low-contrast scene will allow more latitude for incorrect exposure than a high-contrast scene.)

### Problems of Measurement

Before digital cinema cameras were developed, video had a dynamic range of about seven stops. You could measure this relatively easily by shooting a greyscale chart and observing the waveform of the recorded image to see where the highlights levelled off and the shadows disappeared into the noise floor. With today’s dynamic ranges into double digits, simple charts are no longer practical, because you can’t manufacture white enough paper or black enough ink.

For his excellent video on dynamic range, Filmmaker IQ’s John Hess built a device fitted with a row of 1W LEDs, using layers of neutral density gel to make each one a stop darker than its neighbour. For the purposes of his demonstration, this works fine, but as Phil Rhodes points out on RedShark News, you start running into the issue of the dynamic range of the lens.

It may seem strange to think that a lens has dynamic range, and in the past when I’ve heard other DPs talk about certain glass being more or less contrasty, I admit that I haven’t thought much about what that means. What it means is flare, and not the good anamorphic streak kind, but the general veiling whereby a strong light shining into the lens will raise the overall brightness of the image as it bounces around the different elements. This lifts the shadows, producing a certain amount of milkiness. Even with high contrast lenses, ones which are less prone to veiling, the brightest light on your test device will cause some glare over the darkest one, when measuring the kind of dynamic range today’s cameras enjoy.

### Manufacturer Measurements

Going back to my original query about the Alexa versus the URSA, let’s see exactly what the manufacturers say. ARRI specifically states that its sensor’s dynamic range is over 14 stops “as measured with the ARRI Dynamic Range Test Chart”. So what is this chart and how does it work? The official sales blurb runs thusly:

The ARRI DRTC-1 is a special test chart and analysis software for measurement of dynamic range and sensitivity of digital cameras. Through a unique stray light reduction concept this system is able to accurately measure up to 15.5 stops of dynamic range.

The “stray light reduction” is presumably to reduce the veiling mentioned earlier and provide more accurate results. This could be as simple as covering or turning off the brighter lights when measuring the dimmer ones.

I found a bit more information about the test chart in a 2011 camera shoot-out video, from that momentous time when digital was supplanting film as the cinematic acquisition format of choice. Rather than John Hess’s ND gel technique, the DRTC-1 opts for something else to regulate its light output, as ARRI’s Michael Bravin explains in the video:

There’s a piece of motion picture film behind it that’s checked with a densitometer, and what you do is you set the exposure for your camera, and where you lose detail in the vertical and horizontal lines is your clipping point, and where you lose detail because of noise in the shadow areas is your lowest exposure… and in between you end up finding the number of stops of dynamic range.

Blackmagic Design do not state how they measure the dynamic range of their cameras, but it may be a DSC Labs Xlya. This illuminated chart boasts a shutter system which “allows users to isolate and evaluate individual steps”, plus a “stepped xylophone shape” to minimise flare problems.

Art Adams, a cinema lens specialist at ARRI, and someone who’s frequently quoted in Blain Brown’s Cinematography: Theory & Practice, told Y.M. Cinema Magazine:

I used to do a lot of consulting with DSC Labs, who make camera test charts, so I own a 20-stop dynamic range chart (DSC Labs Xyla). This is what most manufacturers use to test dynamic range (although not ARRI, because our engineers don’t feel it’s precise enough) and I see what companies claim as usable stops. You can see that they are just barely above the noise floor.

### Conclusions

Obviously these ARRI folks I keep quoting may be biased. I wanted to find an independent test that measures both Blackmagics and Alexas with the same conditions and methodology, but I couldn’t find one. There is plenty of anecdotal evidence that Alexas have a bigger dynamic range, in fact that’s widely accepted as fact, but quantifying the difference is harder. The most solid thing I could find is this, from a 2017 article about the Blackmagic Ursa Mini 4.6K (first generation):

The camera was measured at just over 14 stops of dynamic range in RAW 4:1 [and 13 stops in ProRes]. This is a good result, especially considering the price of the camera. To put this into perspective Alan measured the Canon C300 mkII at 15 stops of dynamic range. Both the URSA Mini 4.6 and C300 mkII are bettered by the ARRI Alexa and Amira, but then that comes as no surprise given their reputation and price.

The Alan mentioned is Alan Roberts, something of a legend when it comes to testing cameras. It is interesting to note that he is one of the key players behind the TLCI (Television Lighting Consistency Index), a mooted replacement for CRI (Colour Rendering Index). It’s interesting because this whole dynamic range business is starting to remind me of my investigation into CRI, and is leading me to a similar conclusion, that the numbers which the manufacturers give you are all but useless in real-world cinematography.

Whereas CRI at least has a standardised test, there’s no such thing for dynamic range. Therefore, until there is more transparency from manufacturers about how they measure it, I’d recommend ignoring their published values. As always when choosing a camera, shoot your own tests if at all possible. Even the most reliable numbers can’t tell you whether you’re going to like a camera’s look or not, or whether it’s right for the story you want to tell.

When tests aren’t possible, and I know that’s often the case in low-budget land, at least try to find an independent comparison. I’ll leave you with this video from the Slanted Lens, which compares the URSA Mini Pro G2 with the ARRI Amira (which uses the same Alev III sensor as the Alexa). They don’t measure the dynamic range, but you can at least see the images side by side, and in the end it’s the images that matter, not the numbers.

# Working with White Walls

White walls are the bane of a DP’s existence. They bounce light around everywhere, killing the mood, and they look cheap and boring in the background of your shot. Nonetheless, with so many contemporary buildings decorated this way, it’s a challenge we all have to face. Today I’m going to look back on two short films I’ve photographed, and explain the different approaches I took to get the white-walled locations looking nice.

Finding Hope is a moving drama about a couple grieving for the baby they have lost. It was shot largely at the home of the producer, Jean Maye, on a Sony FS7 with Sigma and Pentax stills glass.

Exit Eve is a non-linear narrative about the dehumanisation of an au pair by her wealthy employers. With a fairly respectable budget for a short, this production shot in a luxurious Battersea townhouse on an Arri Alexa Classic with Ultra Primes.

### “Crown”-inspired colour contrast

It was January 2017 when we made Finding Hope, and I’d recently been watching a lot of The Crown. I liked how that series punctuated its daylight interior frames with pools of orange light from practicals. We couldn’t afford much of a lighting package, and I thought that pairing existing pracs with dimmers and tungsten bulbs would be a cheap and easy way to break up the white walls and bring some warmth – perhaps a visual representation of the titular hope – into the heavy story.

I shot all the daylight interiors at 5600K to get that warmth out of the pracs. Meanwhile I shaped the natural light as far as possible with the existing curtains, and beefed it up with a 1.2K HMI where I could. I used no haze or lens diffusion on the film because I felt it needed the unforgiving edges.

For close-ups, I often cheated the pracs a little closer and tweaked the angle, but I chose not to supplement them with movie lamps. The FS7’s native ISO of 2500 helped a lot, especially in a nighttime scene where the grieving parents finally let each other in. Director Krysten Resnick had decided that there would be tea-lights on the kitchen counter, and I asked art director Justine Arbuthnot to increase the number as much as she dared. They became the key-light, and again I tweaked them around for the close-ups.

My favourite scene in Finding Hope is another nighttime one, in which Crystal Leaity sits at a piano while Kevin Leslie watches from the doorway. I continued the theme of warm practicals, bouncing a bare 100W globe off the wall as Crystal’s key, and shaping the existing hall light with some black wrap, but I alternated that with layers of contrasting blue light: the HMI’s “moonlight” coming in through the window, and the flicker of a TV in the deep background. This latter was a blue-gelled 800W tungsten lamp bounced off a wobbling reflector.

When I saw the finished film, I was very pleased that the colourist had leant into the warm/cool contrast throughout the piece, even teasing it out of the daylight exteriors.

### Trapped in a stark white townhouse

I took a different approach to colour in Exit Eve. Director Charlie Parham already knew that he wanted strong red lighting in party scenes, and I felt that this would be most effective if I kept colour out of the lighting elsewhere. As the film approaches its climax, I did start to bring in the orange of outside streetlamps, and glimpses of the party’s red, but otherwise I kept the light stark and white.

Converted from a Victorian schoolhouse, the location had high ceilings, huge windows and multiple floors, so I knew that I would mostly have to live with whatever natural light did or didn’t shine in. We were shooting during the heatwave of 2018, with many long handheld takes following lead actor Thalissa Teixeria from room to room and floor to floor, so even the Alexa’s dynamic range struggled to cope with the variations in light level.

For a night scene in the top floor bedroom, I found that the existing practicals were perfectly placed to provide shape and backlight. I white-balanced to 3600K to keep most of the colour out of them, and rigged black solids behind the camera to prevent the white walls from filling in the shadows.

(Incidentally, the night portions of this sequence were shot as one continuous take, despite comprising two different scenes set months apart. The actors did a quick-change and the bed was redressed by the art department while it was out frame, but sadly this tour de force was chopped up in the final cut.)

I had most control over the lighting when it came to the denouement in the ground floor living area. Here I was inspired by the work of Bradford Young, ASC to backlight the closed blinds (with tungsten units gelled to represent streetlights) and allow the actors inside to go a bit dim and murky. For a key moment we put a red gel on one of the existing spotlights in the living room and let the cast step into it.

So there we have it, two different approaches to lighting in a while-walled location: creating colour contrast with dimmed practicals, or embracing the starkness and saving the colour for dramatic moments. How will you tackle your next magnolia-hued background?

For another example of how I’ve tackled white-walled locations, see my Forever Alone blog.

# “Above the Clouds”: The Spoiler Blogs

During 2016-2017 I blogged about the production of Above the Clouds, a comedy road movie which I shot for director Leon Chambers. It premiered at Raindance in 2018, closely followed by Austin Film Festival, where it won the audience award for Best Narrative Feature, the first of four gongs it would collect.

In two decades of filmmaking, Above the Clouds is easily in the top five productions I’m most proud of. Since this January it has been available on AmazoniTunesGoogle Play and other platforms, and I highly recommend you give it a watch. DO NOT continue reading this blog unless you have, because what follows are two blog entries that I held back due to spoilers.

### DAY 14

(from Week 3)

The script calls for Charlie to be seen sitting in the window seat of a plane as it rises quite literally above the clouds. This is another micro-set filmed in Leon’s living room, in fact half in the living room and half in the hall, to leave enough room for the lights beyond.

Although the view out of the window will be added in post, I need to simulate the lighting effect of bursting through the clouds. My plan involves a 1.2K HMI, and a 4×4 poly board held horizontally with a triple layer of 4×4 Opal sheets hanging from one edge.

We start with the HMI pointed straight into the window and the poly board held high up so that the Opal hangs in front of the lamp. As the plane supposedly rises through the cloud layer, Colin lowers the poly until it is below the level of the lamp, while Gary tilts the HMI down so its light skips off the poly (like sun skipping off the top of clouds) and bounces back up into the window. Gary then tilts the HMI back up to point straight into the window, to suggest further banking or climbing of the aircraft. This direct light is so hot that it bounces off the armrest of Charlie’s seat and gives a glow to her cheek which syncs perfectly with a smile she’s doing.

### DAY 25

(from February 2017 pick-ups)

Today’s set is a dark room. A photographer’s dark room, that is. Not just a random dimly-lit room.

We begin with only the red safe-light in play. The wall-mounted practical has a 15W bulb, so it needs some serious help to illuminate the room. Micky rigs a 1K pup with Medium Red gel and fires it over the top of the set, above the practical. The effect is very convincing. Pure red light can make everything look out of focus on camera, which is why I chose the slightly magenta Medium Red gel, rather than the more realistic Primary Red. The colourist will be able to add some green/yellow to correct this.

During the scene, Naomi pulls a cord and the normal lights come on. These are two hanging practicals, fitted with dimmed 100W tungsten globes. In a very similar set-up to yesterday, we use a 2K with a chimera, poking over the set wall on the camera’s down-side, to enhance and soften the practicals’ light.

# Pick-ups for “Rory’s Way”

In August 2016 I was recommended to a production manager who was crewing up a small pick-ups shoot in London. The pick-ups were for Rory’s Way, or The Etruscan Smile as it was then known, a \$12 million feature based on the best-selling novel of the latter name, starring Brian Cox and Thora Birch. Apparently test screenings had shown that the film’s ending wasn’t quite satisfying enough, and parts of it were to be remounted.

I was given a storyboard consisting of actual frame-grabs from the original version of the scene, alongside notes explaining how the action would be different. Not to give too much away, but the scene involves Brian’s character in bed, and a baby in a cot next to him. The changes simply involved Brian giving a different reaction to what the baby is doing. The bed was to be set up on stage against a blue screen, and composited into backgrounds extracted from the principal photography footage. The baby’s performance was not to be changed, so he was to be rotoscoped out of the original footage too.

I was sent the camera report, 2nd AC’s notebook and script notes from principal photography. The crew had known that the view out of the bedroom window would be added in post, and that separate takes of the baby and Brian would be digitally combined, so they recorded plenty of information for the VFX team. Between the three documents, I had the focal length, focal distance, aperture, white balance, shutter angle, filters, lens height and tilt of every set-up in the scene.

My next step was to email  the main unit DP, who was none other than Javier Aguirresarobe, ASC, AE – the man behind the lens on Thor: Ragnarok, Nicole Kidman vehicle The Others, two of the Twilight films, and Woody Allen’s Vicky Cristina Barcelona. Needless to say, I was honoured to be recreating the work of such an experienced cinematographer.

Javier told me that he had shot with Arri/Zeiss Master Primes, and explained the feel and colour of lighting he had been going for. He had used an 81C (coral) filter to warm up the image a little, and a 1/8th Black Promist for diffusion.

After that, I sat down over coffee with Ben Millar, my gaffer. We analysed the footage from principal photography and reverse-engineered the lighting. I say “we”; it was mostly Ben. This is why a DP hires a good gaffer!

The pick-ups shoot was a single day. The afternoon before, the director and the camera department convened at the studio. The plan was to go through each of the set-ups using a stand-in in the bed. For each set-up, we first used the camera logs and script notes to put on the correct lens and filters, and set the sticks to the right height and tilt. Then, with a print-out of the original shot taped underneath the monitor, we nudged the camera around until we had the closest possible match in framing. This done, ACs Max Quinton and Bex Clives marked the tripod position on the floor with tape, writing the lens length, height, filters etc. on the tape itself to make things super-efficient the next day.

On the morning of the shoot, the lighting department had two or three hours to set up before Brian was called. We used mostly Kinoflos, with a lot of flags to represent window frames through which light sources had been shining on the original set. The VFX supervisor Stephen Coren and I checked the histograms on the monitor to ensure the blue screen was lit evenly and to the level he required.

We were ready to roll in plenty of time, and things went more or less to plan, with the addition of an extra shot or two. The editorial team were in the next room, checking our shots against the original material, and they reported that all was well.

We finished up with a single wide night interior shot for an earlier scene in the movie. This was an interesting one, because we had to extrapolate the lighting for the whole room from a single close-up that had been shot in principal photography. Our wide shot, recorded entirely against blue, would be dropped into a wide shot from principal – a daylight wide shot, that would be digitally painted and retimed for night.

At the time of writing, Rory’s Way has just hit UK cinemas, but I have yet to see it. For all I know it might have been re-edited again, but hopefully my shots are still in there! Either way, it was a fascinating exercise to analyse and reproduce the work of a top cinematographer.

# “The Little Mermaid”: Sun, Sea and Cinematography

(Spoiler alert!) The denouement of The Little Mermaid takes place in the waves on a picturesque beach, where Cam (William Moseley) has carried Elizabeth (Poppy Drayton). In true fairytale style, our hero and heroine finally share their first kiss, parting to reveal the flaring orange sun behind them, just above the horizon. By the time we got to this sequence, we had already shot some water scenes, but those were in controlled, studio-like conditions. Working with natural light and real waves was going to be a whole different ball-game.

Here are some extracts from my diary, revealing how this magical moment was ultimately captured.

### Day 22

Scenes at the beach today, with actors in the ocean. We’ve been worried about this sequence since the earliest stages of preproduction. Will the cast get too cold? Will it be too dangerous with waves and jellyfish and razor-sharp oyster beds? Will we get the magical dawn lighting the script requires? Building a partial beach set against green-screen was considered for a long time, but eventually shooting on a real beach, and this one particular beach, turned out to be our only option. (We’re back on Tybee Island, the same island we did the Shirley Shoot on so very long ago, and Baywatch seems to have all the other beaches tied up.)

The weather is good, with a cloudless sky. We’re cheating sunset for sunrise, and I know exactly where the sun will go down, thanks to the Helios and Sun Tracker apps.

We get ready to go into the water shortly after 6pm. The ACs put the camera in the splash bag and we bring it into the ocean. It starts to leak. Which is pretty much the last thing you want to happen. We pull it out before the camera gets damaged, but now we’re wondering how to shoot the scene. Someone suggests I just put the camera on my shoulder (I’m only going in up to my waist) and a couple of the crew spot me to make sure I don’t drop it. Sounds risky, doesn’t it? But it works. Meanwhile Captain Dan joins us in his waders to hand-bash a polyboard bounce, and the ‘B’ camera team are on a pontoon trying to get alternate angles.

Perhaps the most important thing I do today is ask Will to pick Poppy up the other way around. You see, when we’re about to turn over, Will picks up Poppy with her head to his right and her tail to his left. But I can see that if they play the scene with Poppy this way around, I will end up framing the two-shot with my back to the sun, losing that magical image of the low sun in the background, and probably casting camera shadows on them to boot. So I ask Will to pick Poppy up the other way around.

As the sun races towards the horizon, we get two magical takes. I’m constantly reframing to keep the setting sun in the background, and as the hero and heroine kiss, it flares out perfectly between them. Everyone is ecstatic.

### Day 23

It’s another beautiful day, and the first task is to go out on the pontoon and shoot Poppy’s double swimming about in the mermaid tail. I use the Angenieux zoom for only the second time (it normally lives on the ‘B’ camera), and for the first time on my shoulder. Damn, that thing’s heavy. But my shoulder has worse to come today.

As sunset approaches, we must shoot pick-ups for Saturday’s water scene with the principal cast. Today the tide is much lower at sunset, and getting out to a deep enough spot (up to around waist or chest level) means walking over very squelchy mud which you sometimes sink in up to your knees, and sharp oyster beds. So instead we get into the water via the pontoon. This boat has a limited capacity, so I’m dropped off on the first trip, before it returns to the dock twice more to get the rest of the cast and crew who are needed. It’s extremely pleasant to swim about in the ocean (more of an estuary really) while we wait.

Line producer Fabio has proudly repaired the leaky splash bag with a \$2 bicycle inner tube patch. 2nd AC Kane, a big spender, added \$5 of tape, and we successfully tested it before we set sail.

Because the splash-bag doesn’t fit our Alexa’s viewfinder, Kane has to hand-bash a 5.6” monitor in a ziplock bag (along with a Teradek receiver and battery) so that I can see what I’m shooting. This works pretty well though. The hardest thing is the mud; it’s impossible to find a firm spot, so during the takes I’m always sinking and trying to keep my balance and follow the action at the same time. Kane has to prop me up on a couple of occasions.

For all the material in the ocean I stick to a (Cooke S4i) 32mm lens; the zoom won’t fit in the splash housing, and lens changes take too long. (The cast can only be in the water for 30 minutes at a time, according to Screen Actors Guild rules.) Although we mostly shoot at water level, where the splash bag floats and is easy to control, one set-up requires me to put it on my shoulder. The weight is quite something, but with help I get the shot.

With the water scenes wrapped, and the tide now higher, we swim back to shore. We’ve been in the water at least three hours, and it was exhausting but a lot of fun too.

That concludes my blog series on The Little Mermaid. If you missed any of the earlier instalments, here are the links:

Don’t forget, if you’re in the UK, the film is currently available from all good high-street DVD retailers and on Amazon as a DVD or download.

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# “The Little Mermaid”: Pools of Light

Although The Little Mermaid takes place mostly on dry land, there were some key scenes involving tanks and pools. These include the moment which introduces the audience to the mermaid herself, played by Poppy Drayton. Here are some extracts from my diary covering the challenges of creating a magical, fairytale look while filming in and around water.

### Day 10

Today we’re inside the big top all day – actually all NIGHT. We can’t shoot during the day because too much daylight bleeds through the canvas of the tent.

We are setting up when a storm hits. The tent starts to blow about in a slightly alarming fashion, rain lashes down outside (and inside, because the tent isn’t very waterproof) and lightning flashes. We are ordered out of the tent, and I run into a waiting mini-van with Joe from art and some of the camera crew. We sit watching the rain and telling stories for half an hour before we can press on.

Around the wall of the tent the art department have hung canvas posters; at the suggestion of gaffer Mike Horton, we uplight these with par cans and par 38s. The design of these fixtures hasn’t changed since the 30s, so we can get away with seeing them in shot. The art dept have sourced four period spotlights which we use as background interest (they’re not powerful enough to really illuminate anything), as well as string-lights.

Ambience comes from a Maxi Brute, with just a couple of bubbles on, firing into the tent roof. After seeing a video test of various diffusers during preproduction, I asked for Moroccan Frost to be added to our consumables list, and we use it for the first time on this Maxi Brute. It gives a lovely muted orangey-pink look to the scene.

We’re shooting our mermaid for the very first time, in a tank in the circus ring. The initial plan is to fire a Source Four straight down into the water to create genuine watery rippling light, while bouncing a par can off a wobbling frame of blue gel to beef up the effect. In the end the Source Four isn’t really cutting it, so instead we rig a 575W HMI, gelled with Steel Blue, to a menace arm and fire it into the tank as toppy backlight. This Steel Blue gelled daylight source, blued up slightly further by the water itself, contrasts beautifully with the Moroccan Frost tungsten ambience which the Maxi Brutes are giving us.

In her mermaid tail and costume, Poppy Drayton looks stunning in the tank. We shoot steadicam angles and some slo-mo to get the most out of the set-up.

### Day 15

Back on stage, and we’re shooting the rocky pool. This set was built before I even arrived in Savannah, so I’ve been waiting a long time to shoot it. It’s built almost right up to the ceiling of the studio (a former supermarket) so it’s challenging to light. The grips build four menace arms and poke two 4×4 Kinos and two 575W HMIs over the sides to cross-light the set and bring out all the texture in it. Where the set ends they put up a 20×20′ greenscreen, which we light with two Kino Flo Image 80s fitted with special chroma green tubes.

After a wide (which didn’t make the final cut), the next set-up is a 2-shot of our leads in the pool itself. We consider arming the camera out over the pool using a jib, but ultimately decide that it’s better for me to join the cast in the pool, with the camera on my shoulder in a splash bag. 2nd AC Kane Pearson joins the pool party as well, and ends up hand-bashing a monitor for me since the splash bag’s designed for a Panaflex film camera and the viewfinder doesn’t line up. I’m reminded of my frustrating splash bag experience on See Saw back in 2007, but this time at least within a few minutes I’ve found a comfortable and effective way to operate the camera, under-slinging it and allowing it to partially float so I don’t have to support the whole weight.

For this shot we’ve added our par-can-bounced-off-a-wobbling-blue-gel gag for watery light ripples, and combined with the real light ripples and the reflections of a 1.2K HMI backlight, the image looks beautiful.

### Day 19

After lunch we shoot the singles for the rocky pool scene. The pool itself has been removed, and the actors sit on stools in a paddling pool, with the set behind them. The paddling pool serves two functions: it catches the water that make-up pours over the actors to make them look wet, and it reflects rippling light onto their faces. This light originates from a par can. At first it flattens out the look, then we figure out that we need to lay black fabric on the bottom of the pool. This stops the par can’s light bouncing directly, while retaining the rippling highlights off the water’s surface. (Check out my article on shooting water for more tips like this.)

In the final edit this was all intercut with some beautiful footage by underwater DP Jordan Klein, shot both at a local diving pool in Savannah and at Weeki Wachee Springs State Park in Florida. The main unit shot another scene in the actual ocean, but I’ll cover that later in this series. In the meantime, next week I’ll reveal some of the tricks and techniques used in shooting The Little Mermaid‘s many sequences in moving vehicles.

# “The Little Mermaid”: Circus Cinematography

The biggest set on The Little Mermaid was the circus, an area the size of a football pitch which was transformed into a period spectacle. The big top and many other pieces were driven across the country from LA, and during our first week of principal photography the art department were hard at work setting it all up and dressing it.

Today’s post is about how I lit the night exterior scenes on this huge set. To that end I’m going to focus on the two biggest shots in the sequence: a tracking shot outside the big top, and the crane-up which first reveals the circus to the audience. Below, as well as my diary entries from the shoot, you’ll find a little behind-the-scenes video I grabbed on my phone for the tracking shot, and a lighting plan for the crane shot.

### Day 7

A couple of daylight pick-ups today, then we start setting up for a big night scene. The camera will dolly with Cam and Elle from the exit of the big top, past candy floss and ‘healing water’ stalls where bits of dialogue will happen, and finally reveal a ferris wheel in the distance. We block while the sun’s still up, and paint in the light as night sets in. We are trying to light most of it in a way that will also work for our big crane shot reveal of the circus later in the week, because repositioning large HMIs – especially the two 18Ks we’re flying on a condor (cherry-picker) – is very time-consuming. Inevitably it doesn’t quite work out that way, and one of the 18Ks has to die for now at least.

The ferris wheel is backlit by a 12K, with a little front-light from a 5K tungsten fresnel. Cross-light on the talent comes from the working 18K and a 6K on the opposite side of frame. Nine-light Maxi Brutes illuminate the tent from inside, some of that light spilling out onto the talent, while par cans uplight a row of banners outside. A 1K baby provides edge-light to the talent in their final position. A 300W fresnel inside the healing water wagon spills out, and a bare 40W globe inside the umbrella of the candy floss stall gives us a little glow there.

The final lamp to go up is another 300W fresnel, because the directors are concerned that the ’sold out’ sign on the healing water wagon isn’t clear enough. We end up firing it in from the front because there’s no time for anything else, but as always with front-light, I deeply regret it. Ideally we would have armed it out from the roof of the wagon to rake down the side of it.

Once the supporting artists are choreographed, the shot looks great.

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### Day 9

We start with a big crane shot revealing the whole circus at night. For this shot we have the following lamps burning: 2 x 18Ks (on a condor), 1 x 12K, 1 x 4K – all those are providing moonlight or starlight, with varying degrees of blue gel on them; 2 x Nine-light Maxi Brutes making the big top glow from inside; a 5K spilling some orange glow on the background; 2 or 3 smaller tungsten units spilling out light from inside the smaller tents; and lighting the foreground, a 4×4 Kino and a 1K baby bounced off unbleached muslin. There are also numerous practicals on, including the lights on the ferris wheel, the illuminated ‘circus’ sign, several par can up-lighters, and about 7KW of fairy lights. Totalling over 80KW, it is easily the biggest lighting set-up of my career. Although the grip and electrical crew is relatively small given the scale of the set-up, they handle it with aplomb.

We have rebuilt our Giraffe crane to its maximum 31ft configuration, so we can swoop up over the entrance tent, past the ’circus’ sign, and reveal the twinkling string-lights of the midway leading to the big top, and the rides beyond.

Here’s a retrospective lighting plan for this crane shot (not to scale); click to enlarge it. Note that additional tents were added in postproduction, as you can see in the trailer.

Ideally we would have had two condors, with an 18K on each, and put one of them way back behind the trees, to maintain a consistent direction of moonlight, but budget and the practicalities of the location made this impossible.

One thing that was a little different to my original plan was the hard 4K edging the roofs of the midway tents on the lefthand side. This was meant to be a pair of 6Ks firing through a diffusion frame, to get a much softer, less “sourcey” look than the hard “moonlight” from the 18Ks. But unfortunately both our 6Ks were malfunctioning.

Another change was the lighting of the midway itself. We had a tungsten helium balloon on the truck, which I had planned to float above the midway to provide warm ambience. As it turned out, the practical string lights, although only 40W each, were so numerous that they provided ample illumination in the centre of the frame.

Later on in production, I was chatting to one of the ADs about this scene and he expressed surprise at how well I had handled it, given that it was so much bigger than any lighting set-up I’d previously done. Honestly it never fazed me. Lighting is entirely scaleable; the principles are identical, whether your set is a small bathroom or a football pitch. I’d done so much night exterior in my career, I’d just never had the big toys I wanted before. I’ll let you in on a secret though: the only reason I knew to ask for 18Ks and a condor was from reading American Cinematographer!

In my next post I’ll discuss shooting some of Poppy Drayton’s key scenes as the eponymous mermaid, including her introduction inside the big top. Don’t forget that The Little Mermaid is currently showing in movie theatres across the US and on Amazon in the UK.

Recently work began on colour grading Above the Clouds, a comedy road movie I shot for director Leon Chambers. I’ve covered every day of shooting here on my blog, but the story wouldn’t be complete without an account of this crucial stage of postproduction.

I must confess I didn’t give much thought to the grade during the shoot, monitoring in Rec.709 and not envisaging any particular “look”. So when Leon asked if I had any thoughts or references to pass on to colourist Duncan Russell, I had to put my thinking cap on. I came up with a few different ideas and met with Leon to discuss them. The one that clicked with his own thoughts was a super-saturated vintage postcard (above). He also liked how, in a frame grab I’d been playing about with, I had warmed up the yellow of the car – an important character in the movie!

Leon was keen to position Above the Clouds‘ visual tone somewhere between the grim reality  of a typical British drama and the high-key gloss of Hollywood comedies. Finding exactly the right spot on that wide spectrum was the challenge!

“Real but beautiful” was Duncan’s mantra when Leon and I sat down with him last week for a session in Freefolk’s Baselight One suite. He pointed to the John Lewis “Tiny Dancer” ad as a good touchstone for this approach.

We spent the day looking at the film’s key sequences. There was a shot of Charlie, Oz and the Yellow Peril (the car) outside the garage from week one which Duncan used to establish a look for the three characters. It’s commonplace nowadays to track faces and apply individual grades to them, making it possible to fine-tune skin-tones with digital precision. I’m pleased that Duncan embraced the existing contrast between Charlie’s pale, freckled innocence and Oz’s dirty, craggy world-weariness.

Above the Clouds was mainly shot on an Alexa Mini, in Log C ProRes 4444, so there was plenty of detail captured beyond the Rec.709 image that I was (mostly) monitoring. A simple example of this coming in useful is the torchlight charity shop scene, shot at the end of week two. At one point Leo reaches for something on a shelf and his arm moves right in front of his torch. Power-windowing Leo’s arm, Duncan was able to bring back the highlight detail, because it had all been captured in the Log C.

But just because all the detail is there, it doesn’t mean you can always use it. Take the gallery scenes, also shot in week two, at the Turner Contemporary in Margate. The location has large sea-view windows and white walls. Many of the key shots featured Oz and Charlie with their backs towards the windows. This is a classic contrasty situation, but I knew from checking the false colours in log mode that all the detail was being captured.

Duncan initially tried to retain all the exterior detail in the grade, by separating the highlights from the mid-tones and treating them differently. He succeeded, but it didn’t look real. It looked like Oz and Charlie were green-screened over a separate background. Our subconscious minds know that a daylight exterior cannot be only slightly brighter than an interior, so it appeared artificial. It was necessary to back off on the sky detail to keep it feeling real. (Had we been grading in HDR [High Dynamic Range], which may one day be the norm, we could theoretically have retained all the detail while still keeping it realistic. However, if what I’ve heard of HDR is correct, it may have been unpleasant for audiences to look at Charlie and Oz against the bright light of the window beyond.)

There were other technical challenges to deal with in the film as well. One was the infra-red problem we encountered with our ND filters during last autumn’s pick-ups, which meant that Duncan had to key out Oz’s apparently pink jacket and restore it to blue. Another was the mix of formats employed for the various pick-ups: in addition to the Alexa Mini, there was footage from an Arri Amira, a Blackmagic Micro Cinema Camera (BMMCC) and even a Canon 5D Mk III. Although the latter had an intentionally different look, the other three had to match as closely as possible.

A twilight scene set in a rural village contains perhaps the most disparate elements. Many shots were done day-for-dusk on the Alexa Mini in Scotland, at the end of week four. Additional angles were captured on the BMMCC in Kent a few months later, both day-for-dusk and dusk-for-dusk. This outdoor material continues directly into indoor scenes, shot on a set this February on the Amira. Having said all that, they didn’t match too badly at all, but some juggling was required to find a level of darkness that worked for the whole sequence while retaining consistency.

In other sequences, like the ones in Margate near the start of the film, a big continuity issue is the clouds. Given the film’s title, I always tried to frame in plenty of sky and retain detail in it, using graduated ND filters where necessary. Duncan was able to bring out, suppress or manipulate detail as needed, to maintain continuity with adjacent shots.

Consistency is important in a big-picture sense too. One of the last scenes we looked at was the interior of Leo’s house, from weeks two and three, for which Duncan hit upon a nice, painterly grade with a bit of mystery to it. The question is, does that jar with the rest of the movie, which is fairly light overall, and does it give the audience the right clues about the tone of the scene which will unfold? We may not know the answers until we watch the whole film through.

Duncan has plenty more work to do on Above the Clouds, but I’m confident it’s in very good hands. I will probably attend another session when it’s close to completion, so watch this space for that.

See all my Above the Clouds posts here, or visit the official website.

# The Cinematography of “Perplexed Music”

In June I was recommended by a mutual friend to shoot a short drama called Perplexed Music, inspired by the Elizabeth Barrett Browning sonnet of the same name. It’s a passion project from writer-director Mark McGann, with his brother Paul McGann (Doctor Who, Alien 3, Withnail & I) in the lead role of a man grieving for his deceased partner.

Mark was keen from the outset to shoot on an Alexa, and I was quick to agree. Arri Rental very kindly gave us an amazing deal on an Alexa Classic and a set of Ultra Primes. As on Above the Clouds, we used a Blackmagic Micro Cinema Camera as a B-cam, capturing two specific angles that were impossible on the Alexa with our limited grip budget.

Throughout July, Mark and I had a very satisfying creative dialogue about the cinematic techniques we would use to tell the story of Paul’s character, The Man, who never speaks. I had been watching a lot of Mr. Robot, and was keen to use unusual compositions as that show does. The visual grammar that we ultimately developed eschewed The Rule of Thirds, either squeezing The Man right into the side of frame – at times when things are too much for him – or placing him dead centre for moments of clarity and acceptance, and for flashbacks to when his partner was alive.

While testing lenses at Arri Rental a few weeks prior to the shoot, I took the opportunity to shoot some frame-rate tests between 24 and 48fps. Since the film has so little dialogue, I figured there was nothing to stop us using a lot of slow motion if we wanted to. I didn’t want it to look like a music video though. I thought perhaps a very subtle over-cranking, creating languid blinks and slightly heavier movement, would add to the burden of The Man’s grief. Mark agreed as soon as he saw the tests, and we ended up shooting a number of set-ups at 28 and 30fps, plus 40fps for a pivotal sequence.

I also tested various ISO settings on the Alexa (click here for full details, stills and video from this test). Based on these, I decided to use ISO 1600 for the majority of the film, partly for the extra latitude in the highlights, and partly to add grittiness to The Man’s grief-stricken world, in the form of a little picture noise. When we started shooting the flashbacks, on the spur of the moment I decided to switch to ISO 400 for these. A few years back I shot the music video below on a Red Epic and, for reasons I forget, one set-up was done at a lower ISO than the rest. I remember the feeling this gave, when I saw the final edit, of everything suddenly being smooth and hyper-real. I thought that would be a great feeling to give to the flashbacks.

Much of Perplexed Music was day exterior, but a couple of sequences required lighting. In the opening café scene, I fired HMIs through two windows, but kept their light away from The Man, keying him with a practical to put him in his own little world. Meanwhile, a happy couple he’s watching are bathed in sunlight (sometimes real, sometimes not) warmed up with a quarter CTO, and bouncing beautifully off their table to give them a healthy glow.

For night interiors at The Man’s home, I was keen to rely on practicals as much as possible. Firstly there wasn’t much space in the little cottage, secondly I didn’t want the hassle of having to shift them around to keep them out of frame when we changed angle, and thirdly it just looks more natural. So aside from a tungsten bounce in a corner of the living room we knew would never be seen, I stuck to practical table lamps and exterior lighting.

I had planned to use direct HMI sources for moonlight through the windows, but my gaffer Sam suggested going softer so that we wouldn’t have hard shadows inside which would need filling. I saw that he was right, so we used a kino through one window and a 2.5K HMI bounced into poly through another (pictured at left).

Perplexed Music was shot over five days in Frome in Somerset and Rame in Cornwall. The latter provided us with a spectacular cliff-top and the isolated St. Michael’s Chapel on the peak of the headland. Here we employed the services of The Fly Company, who captured two dramatic, sweeping shots on their DJI Inspire 2 drone. We were all extremely impressed by what they were able to achieve, especially as it was done in very windy conditions, in between rain showers.

We completed the final set-ups of the schedule as the winds began gusting up to 60mph, and poor Paul could barely stand upright! I was certainly glad we picked the Alexa to shoot on, because anything lighter would probably have shaken during takes, if not blown over!

I had a fantastic time working with Mark and Paul, and the whole cast and crew. We were sad to part ways at the end of the week, and we all look forward to seeing the finished film soon. And at this point, dear reader, I ask for your help. Currently a Kickstarter campaign is underway for postproduction. It’s well over 50% funded at the time of writing, but every little helps in our quest to reach the finishing line. Rewards for backers include thank you video messages from Paul and Mark, and tickets to a private screening in December. Even if you can’t contribute, please consider sharing the page on social media. Thanks!

https://www.kickstarter.com/projects/perplexedmusic/perplexed-music-post-production

# Anamorphic Lens Tests

Anamorphic cinematography, first dabbled with in the 1920s, was popularised by Twentieth Century Fox in the fifties as CinemaScope. Television was growing in popularity and the studios were inventing gimmicks left, right and centre to encourage audiences back into cinemas. Fox’s idea was to immerse viewers in an image far wider than they were used to, but with minimal modifications to existing 4-perf 35mm projectors. They developed a system of anamorphic lenses containing elements which compressed the image horizontally by a factor of two. By placing a corresponding anamorphosing lens onto existing projectors, the image was unsqueezed into an aspect ratio of 2.55:1, or later 2.39:1.

Since those early days of CinemaScope, anamorphic cinematography has become associated with the biggest Hollywood blockbusters. Its optical features – streak flares, oval bokeh and curved horizontal lines – have been seared into our collective consciousness, indelibly associated with high production values.

I’ve not yet been fortunate enough to shoot anamorphic, but I was able to test a few lenses at Arri Rental recently, with the help of Rupert Peddle and Bex Clives. Last week I wrote about the spherical lenses which we tested; our anamorphic tests followed the same methodology.

Again we were shooting on an Alexa XT Plus in log C ProRes 4444 XQ, this time in 4:3 mode, a resolution of 2048×1536. Since all of the lenses had a standard 2:1 anamorphosing ratio, the images unsqueezed to a super-wide 2.66:1 ratio. (This is because the lenses were designed to be used on 35mm film with space left to one side for the optical soundtrack.) You can see the full width of this ratio in the first split-screen image in the video, at 2:08, and in the second image below, but otherwise I have horizontally cropped the footage to the standard 2.39:1 ratio.

We tested the following glass:

 Series Length Speed CF* Weight Hawk V 35mm T2.2 30″ 5.6kg Cooke Xtal 30mm T2.8 ? 3kg Kowa Mirrorscope 40mm T2.2 36″ 1.15kg Kowa Mirrorscope 30mm T2.3 ? ?

* CF = close focus

For consistency with the spherical lenses, we used lengths around 32mm, but in the anamorphic format this is a pretty wide lens, not a mid-range lens. We shot at T2.8, again for consistency, but I hear that many anamorphics don’t perform well wider than T4.

We were only able to test what Arri Rental happened to have on the shelves that day. The biggest and presumably most expensive was the Hawk V-series. Next  in size and weight was the Cooke Xtal – pronounced “crystal” – a 1970s lens based on the much-loved Speed Panchros. The smallest and lightest, was the Kowa Mirrorscope, with a list price of £1,200 per week for a set of four. (Sorry, I couldn’t find any pricing info for the others online.) Note that there isn’t really a 30mm Mirrorscope; to get this length you put a wide angle adapter on the 40mm. As this extra element decreases the optical performance, we tested it with and without, hence the two lengths.

Here’s the video…

### Skin tones

Click on the image to see it at full quality.

To my eye, the Hawk has a fairly rich, warm skin tone, while the Cooke – as with the spherical S4 tested last week – seems a little grey and flat. The Kowa is inexplicably brighter than the other two lenses, which makes it hard to compare, but perhaps it’s a little cooler in tone?

### Sharpness

Focus is more critical with anamorphic lenses than spherical ones. From a forum posting by Max Jacoby:

Anamorphic lenses have what is known as a “curved field of focus” that works similarly to the curved movie screens in some large Cinerama theatres. This is one reason that one needs to expose these lenses at a deeper stop. If one doesn’t, the curved field will not be covered by depth of field and either the edges or centre of the frame will be soft.

One day I’d like to re-test these lenses at a lower stop, T4 or T5.6, where they will all undoubtedly perform much better. But in this T2.8 test, on Bex’s face in the centre of frame, the Hawk V and the Kowa Mirrorscope 40mm – both almost a full stop from their maximum apertures – are clearly the sharpest of the bunch. The Cooke Xtal, which is wide open, is unsurprisingly softer. The 30mm adapter on the Mirrorscope completely destroys the image, not only making it very soft but also introducing colour aberration.

Now let’s look at the checkerboard at the side of frame and see if we can spot any differences in sharpness there…

It seems to me that the Kowa, both with and without the adapter, has a greater difference in sharpness between the centre and edges of frame than the the Hawk and Cooke. With the latter two lenses, the checkerboard is reasonably sharp, at least on the lefthand side, with some ghosting/blur visible towards the righthand side. The same thing can be observed on the chart in the flare tests at the end of the video.

### Breathing & Bokeh

All of these lenses have a noticeable degree of breathe, which I suppose is to be expected from anamorphics. The Hawk V has roughly oval bokeh, the Cooke’s is more circular, while the Mirrorscope has interesting D-shaped bokeh.

### Flare

The Hawk V doesn’t flare much at all, which is apparently due to the anamorphic element being in the middle of the lens, rather than at the front. The Kowa has a nice streak and glow around the light source, with a funky purple artefact on the opposite side of frame. But it’s the Cooke Xtal which provides the most classic lens flare, with a horizontal line across most of the frame and a partial star pattern around the source, despite the lens being wide open.

At the end of the video you can see how the flares develop on each lens as the light source moves horizontally across frame.

### Distortion

A bulging effect is very obvious on all of these lenses, due to the focal lengths being quite wide for anamorphic. Notice how at 40mm on the Kowa Mirrorscope this curvature of the image is significantly reduced.

It’s hard to compare the levels of distortion because none of the focal lengths are exactly the same, except for the Cooke Xtal and the Kowa Mirrorscope with the 30mm adapter on. The Cooke’s top right and bottom left corners appear to be stretched away from the centre relative to the other two corners. I suppose that strange and funky stuff like this is exactly why you choose vintage glass.

Interestingly, the Cooke’s image appears a little tighter than the Kowa’s, which combined with my inability to find any evidence online of the existence of a 30mm Xtal, leads me to suspect we may have been given a mislabelled 32mm.

### Conclusions

When we got to the end of our spherical tests and started putting the anamorphics on, I was shocked by the drop in sharpness. But as noted earlier, this is because anamorphics really need to be used with a smaller aperture than the T2.8 I often shoot at. If I learnt nothing else from this test, I learnt that anamorphic needs more light!

I would love to put the Cooke Xtal’s lovely flares and general vintage look to good use on a period movie one day. The Hawk V would be a good choice if I wanted the anamorphic look with warm, dynamic skin tones. The Kowa system seemed a little cheap and cobbled-together, but could well be a good solution for anamorphic on a budget, as long as I stayed away from the 30mm adapter!

I hope you’ve found these tests useful. Thanks again to 1st AC Rupert Peddle, 2nd AC Bex Clives and Arri Rental UK for making them possible.