The Sunny 16 Rule in Cinematography

If you’ve done much still photography, particularly on celluloid, you will probably have heard of the Sunny 16 Rule. It’s a useful shortcut for correctly exposing bright day exteriors without needing a light meter. Is it of any use in digital cinematography though? Yes, and I’ll explain how.

 

How the rule Works

Sunny 16 is very simple: if the sun is out, set your aperture to f/16 and your shutter speed denominator to the same as your ISO. For example, at ISO 100 set the shutter to 1/100th of a second. At ISO 400 set the shutter to 1/400th of a second – or 1/500th of a second, if that’s the closest option the camera permits – and so on.

You can use the rule to work out other combinations from there. Say your ISO is 100 but you want the sharper, less motion-blurred look of a 1/400th shutter. That’s two stops slower, so open the aperture from f/16 to f/8. (Check out my exposure series if this is all Dutch to you.)

The Sunny 16 Rule works because the sun outputs a constant amount of light and is a constant distance from the earth – at least constant enough to make no significant difference. The sun’s illuminance at the earth’s surface is about 10,000 foot-candles. The following formula relates illuminance (b) to f-stop (f), shutter speed (s) and ISO (i):

Using Sunny 16 in the case of ISO 100 and a shutter speed of 1/100th of a second, this formula gives us…

… 6,400 foot-candles. Less than 10,000fc, certainly, but remember this is only a rule of thumb – and one designed for film, which isn’t hurt at all by a little over-exposure. The rule probably accounts for the fact that you may want to see into the shadows a bit too. (See my article “How Big a Light Do I Need?” for explanations of illuminance and foot-candles and more on the above formula.)

Anyway, you can see from the equation why the shutter speed denominator and ISO cancel each other out if they’re the same.

 

Using the rule in cinematography

A few weeks ago when I was on the banks of the River Cam setting up for a scene in Harvey Greenfield is Running Late, my 1st AC Hamish Nichols asked which ND filter I wanted in the matte box. It was 5:30am; the sun had barely risen and certainly wasn’t high enough yet to reach me and my light meter over the trees and buildings on the horizon. But I knew that it would be hitting us by the time we turned over, and that the weather forecast was for a completely cloudless day, indeed the hottest day of the year at that time. So I was able to predict that we’d need the 2.1 ND.

How did I work this out? From the Sunny 16 Rule as follows:

  • I was shooting with a 1/50th of a second shutter interval (a 172.8° shutter angle at 24fps), so the Rule told me that f/16 (or T16) at ISO 50 would be the right exposure.
  • I was actually at ISO 800, which is four stops faster than ISO 50. (Doubling 50 four times gives you 800.)
  • I wanted to shoot at T5.6, which is three stops faster than T16.
  • That’s a total of seven stops too much light. To find the right optical density of ND filter you multiply that by 0.3, so 0.3 x 7 = 2.1. (More on this in my ND filters post.)

Everything on a film set sucks up time, so the more you know in advance, the more efficient you can be. Little tricks like this mean you don’t have to do a last-minute filter swing and waste five minutes that the director could have used for another take.

The Sunny 16 Rule in Cinematography

“Harvey Greenfield is Running Late”: Week 3 Part 2

Day 21

Photo by Jonnie Howard

A morning full of short running scenes, all shot as oners on the Steadicam by Luke Oliver. Pretty much every crew member had had a cameo by this point, and today it was my turn. My character: Nerdy Cyclist. Alright, technically it was just Cyclist. The nerdy bit was just me (a) beefing up my part and (b) playing to type.

For the afternoon we moved to The Lab, a cocktail bar, where we filmed one of the fantasy/imaginary scenes that cuts with the very first shot we did of Harvey back on Day 1. Mixologist Tom was dressed in an elaborate all-black costume so Stephen and I hit him with two tungsten lamps, one either side, at an angle somewhere between side-light and backlight. This cut him out from the background, showed up the layering in the costume, edge-lit the cocktail shaker and liquids being poured, and deliberately kept Tom’s face dark. Quadruple win!

 

Day 22

We returned to Othersyde to pick up the one scene we dropped there on our most packed day of principal photography, Day 7. I referred to the blog post to help get the vibe of the lighting the same. The main motivation was the real streetlamp at the front of the site, which we wrapped using an Aputure with a lantern attachment, rigged on a mini boom. Another Aputure lantern gave a cool moonlight wash on the venue’s terraced outdoor seating, and a blue-gelled 300W tungsten fresnel uplighter replicated what we did on the other side of the building last year. A 2K blasted light from the direction Harvey has come; this light represented the ongoing wedding, so we had a couple of people moving around in front of it for dynamic shadows.

I ended up turning off the first Aputure for the wide as it seemed to kill the mood, but we brought it back for the close-up to show more of Paul’s face. To represent the light of his phone as he turns it on, Stephen held a PavoTube just above the camera and twisted it quickly around to face Paul on cue. We adjusted the eyebrow on the camera to flag the tube’s light off the phone itself.

There were a few bitty pick-ups to do while we were outside with access to power, including a “BOV” – a POV of a bee. We did this with the probe lens on Jonnie’s Canon C200, which I had to float around and then jab into Paul’s neck. Sorry, Paul.

At 1am we moved into an adjacent industrial street – having decided that it was unreasonable to have Paul shouting dialogue in a residential area at that hour – for some Steadicam shots. I went to the Gemini’s low-light ISO 3200 and Stephen hand-bashed a lantern on a boom pole to fill Paul in between streetlamps, which became a fun dance when we had to do a 270° orbit!

 

Day 23

We convened at Cambridge’s Castle Hill. Nearby Indian restaurant Namaste Village kindly agreed to let us shoot a brief scene there at the last minute, even having one of the staff do a spot of acting. I posted a video breakdown on Instagram – here it is:

 

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Back outside we filmed a nice sequence of shots ending with a 360° pan following Harvey as he walks around the top of Castle Hill talking on the phone. As the other end of the phone call had been shot with Steve’s head sometimes out of frame, we went the other way and gave Harvey loads of headroom, capturing some nice clouds along the way.

Then it was time for another pick-up from Day 7, reshooting the tent scene for continuity reasons. Again we put a light on one side and black-draped the other to get some shape into the light inside. This time we used a wider lens, the 14mm, and with the help of a runner I handheld it over Paul rather than trying to squeeze the tripod in around him like last time. He got a nasty shock when I accidentally knocked the matte box off and it hit him in the face. Er, sorry again.

After wrapping a few of us went back across the road to Namaste Village, where the food was excellent.

 

Day 24

On our last day we caught up to the elusive pick-up that was always meant to be a pick-up: the scenes with Harvey’s mum. We took over Rachel’s grandmother’s house for several hours, most of the shots being in a corner of her living room. Unusually I was drawn to a corner that didn’t have a window in it, because it had the best furniture and dressing to establish the character in our standard 24mm tableau shot.

But this meant – with all the windows behind camera – that it was a challenge to make the lighting interesting. We faked a window just off camera left using a diffusion frame with muslin and a grid over it; Stephen bounced the 600D into it from across the room. I closed the room’s curtains as much as I could get away with before the lack of natural fill light started to make it look like night. (For later scenes we closed them all the way and put a 300D behind the muslin, as pictured above.)

To add more interest to the shot I played around with the positions of two table lamps and a floor lamp. Pausing to check my script breakdown notes from last year I saw that I had written “a single practical floor lamp” in the lighting column; too many lamps would kill the scene’s sad tone. This is a good example of a breakdown keeping me honest as a DP and preventing me from getting carried away doing stuff on set just because I can (though that definitely still happens sometimes). I ended up with just one lamp in the back of the main shot.

After some variations on that main shot for later scenes, and a brief scene in the kitchen, we packed up and headed out for exteriors. Most of these were happy flashbacks from the early days of Harvey and Alice’s relationship, and Jonnie wanted to fill them with filmic references. First up was a Jules et Jim homage with the pair racing across a bridge, then a “remake” of one of Jonnie’s own amateur films with Harvey and Alice spinning around holding hands. For POV reverse shots we put the tripod on the point which they span around, and I set the panning tension to zero so that they could pull the camera around themselves by holding the moose bars (handgrips).

Next was a Manhattan-esque shot with the couple on a bench looking up at Ely Cathedral. We clearly weren’t going to light the cathedral on our budget, so we set up around sunset and waited for the streetlamps to come on and the ambient light to drop to a nice dusky level. We rolled when the daylight was metering at T1.4 at ISO 800, though I exposed at T2. To cut Harvey and Alice out from the background a bit Stephen stood just out of frame with an LED lantern motivated by a nearby streetlamp.

He pulled the same trick at our next location, a passageway beside Prezzo, where we did actually have to light a small portion of the cathedral wall as well, using a battery-powered Aputure (200X I think). We couldn’t have done it for long on the batteries we had, but fortunately it was a brief scene.

Our final set-up was a Poor Man’s shot of Harvey running at night. We did this on the green beside the cathedral because it was a handy open space where we could get a completely dark background save for a few dots of distant lights. Stephen armed a FalconEyes over Paul and swung it back and forth to create the illusion of passing streetlamps. The shot needed a tiny touch of fill, so we taped a PavoTube to the top of the matte box, setting it to 1% intensity and taping over most of it to get it down to a low enough level. (I was at ISO 3200 and on a 14mm lens, so mere inches from Paul’s face.)

Then Rob said the magic words, “It’s a wrap.” Like most micro-budget projects there are still a few loose ends to be shot, but those will be done with Jonnie’s camera and no crew. For most of the cast and crew Harvey Greenfield has run his course and I’ll see them at some distant time for the premiere. Thank you Stephen Allwright (gaffer), Jeremy Dawson (spark), Hamish Nichols (1st AC), Fiyin Oladimeji (2nd AC) and Nana Nabi (2nd AC daily) for all your hard work, and to Jonnie for bringing me onto this fun and creative film. Huge thanks also to Global Distribution, Red and Sigma who supported us with equipment which brought the whole thing up a level. The rough cut is already fantastic and I can’t wait to see it finished.

Read all my Harvey Greenfield is Running Late posts:

“Harvey Greenfield is Running Late”: Week 3 Part 2