How to Get The Perfect Exposure Every Time on a Shoot, With Award-Winning Filmmaker Ollie Kenchington
Ollie Kenchington is an award-winning filmmaker and highly respected film production and postproduction trainer. He is the owner and senior colourist at Korro Films (a UK-based, award-winning film production agency) and founder and lead tutor at Kurro Academy (a Blackmagic Design Certified Training Partner, offering colourgrading training and much more).
He is also an educator at Mzed, one of the leading online education resources for filmmakers, and a proud partner of My RØDE Reel. One of the courses he teaches is Directing Colour, which explores how visual language cues, colour theory and colour grading techniques can be used throughout the filmmaking process to not just create a “look” but to enhance storytelling. The course is FREE when you download the My RØDE Reel starter pack (it's usually $79!).
Below, Ollie dives into his tips for perfecting exposure while you're on a shoot.
"When youʼre starting out as a filmmaker, it can be disheartening to spend a long time shooting something, only to discover it wasnʼt as well exposed as you thought it was on the day. So when RØDE asked me to offer some top tips for filmmakers, I thought Iʼd focus on this particular aspect of shooting..."
How To Get The Perfect Exposure Every Time on a Shoot
When it comes to exposure, there are a couple of simple tricks you can use to nail it in-camera every time. If you have a chart, like the X-Rite ColorChecker Video, or something similar, you should find there are two parts of it that you can use.
One is an 18% reflectance grey and the other is a 90% reflectance white. If you hold these charts in your scene (where your subject is) you can use the built in zebras on your camera to tell when they are at the correct exposure. For 18% grey (aka middle grey) you should choose zebra 1, and set it to 50%, with a +/- 5% variance.
If you are going by the 90% reflectance part of the chart, you should go for zebra 2, and set it to 90%. If your scene has no more than ten stops of dynamic range, and you are using a standard gamma curve, then you should find this gives you perfect and consistent results every time.
If you are shooting a scene that has more than ten stops of dynamic range, you can follow the same procedure, but once youʼve got the chart at the correct level, cycle through any other gamma settings you have in your camera (e.g. Wide DR, C-log, S-log2 etc) until you find one where your, previously clipped, highlights are now showing detail.
If none of them give you detail in the brightest highlights, it simply means your scenes dynamic range exceeds the capability of your camera. You then need to set about reducing the scenes dynamic range, which will entail either reducing the brightest highlights (ND gel or cloth on windows, for example) or bringing up the darkest shadows (adding lights) to raise your ambient exposure bed.
Note, however, that if you are shooting outside, with bright sunshine in your scene, raising the exposure bed becomes a time-consuming and/or expensive endeavour!
If you have no chart with you, it obviously makes it harder to set exposure so accurately, as the world tends not to have perfect 18% and 90% references in it. For this reason, it can be useful to use an external monitor that has a ‘false colourʼ exposure assist mode built in.
With these types of assistive tools, colours are overlaid on the objects in your scene to help you identify how bright they are. Although there will be a lot of data on your screen, if you practice with a false colour overlay, you can get very good at quickly judging not only if your subject is ideally exposed or not, but the comparative ratio of your subject in relation to the other parts of your composition.
Some camera manufacturers recommend you over-expose when using certain gamma curves, in order to clean up noisy shadows. If you are told to overexpose your image by, say, two stops, a quick and easy way to do that is to follow all of the above recommendations, but have a two-stop ND applied (either internally, or using filters) whilst you do it. When you are done exposing normally, simply turn off/take off the two-stop ND, and you will be exactly two stops over exposed.
Finally, when it comes to producing as clean an image as possible, it is advised to keep your camera at itʼs native, or base, sensitivity setting when exposing. At this level, no additional signal boosting (gain) will be being added in the camera, meaning you will get the cleanest possible image.
If you are unsure what your cameraʼs base ISO is, one simple trick you can use is to set your camera to show sensitivity in decibels (rather than ISO) and make sure it reads 0dB. 0dB equals no gain, so if you set it to 0dB, then flick back to showing ISO in the menu, whatever ISO your camera now shows, is the base sensitivity of that camera.
Learn more about the craft of mastering colour in film by downloading Ollie's Directing Colour course - FREE when you download the My RØDE Reel starter pack.
And find out more about My RØDE Reel here.