High dynamic range cameras are currently all the rage with filmmakers, and for good reason. After all, more dynamic range typically helps to emulate the film look that so many of us are after… But the reality is dynamic range will only get you part of the way there. To really get that filmic quality in your images, you need to make sure your highlight rolloff is in check.
Since I started working professionally in film I’ve seen the focus of filmmakers shift many times, technologically speaking.
First it was 24p.
When we realized that camcorders with a 24p mode were able to produce a much more filmic image than the usual 59.94i recording cameras, we all jumped on board. DVX100’s sold like crazy and we were all happy for a while. That is, until we realized we needed shallow depth of field to capture an even more cinematic image.
For a while, we struggled with clunky 35mm adapters that helped us use proper cinema lenses on our small sensor camcorders, and achieve a shallower DOF. But as we all know, those became irrelevant quickly once video based DSLRs hit the market.
And while many of us were content to shoot on our 5D’s and 7D’s for several years, eventually we realized we needed more dynamic range. DR was amongst the biggest differentiator between high quality DSLR cameras and high end cinema cameras. Sure there were many other obvious differences (ergonomics, recording format, audio handling, etc.), but really dynamic range was the biggest hurdle for many DSLR filmmakers to overcome, since solving the issue of shallow DOF.
Recently we’ve been fortunate enough to see lower cost cinema cameras and DSLRs implement log settings or other features that have allowed for higher DR recording. Manufacturers like Sony, Blackmagic Design, and even Canon (on their cinema line) have been able to give us anywhere from 13 to 15 stops of DR on relatively low cost cameras. That’s pretty great, considering those numbers aren’t far off from your average film stock.
That said, there is a reason why your Sony A7S log footage can’t hold a candle to Arri Alexa footage. Well actually, there are a lot of reasons… Color science, motion cadence, sensor technology, etc. But all things considered, the biggest differentiating factor is the highlight rolloff. If you were to capture two nearly identical images – One on an Alexa and one on a lower cost cinema camera, and color correct them both to match as closely as possible, the most obvious difference between the two images would be how the highlights are handled…
What Exactly Is Highlight Rolloff?
For those of you that don’t quite get exactly what I mean by highlight rolloff, I’ll try to explain it briefly here for you.
The easiest way to understand highlight rolloff is by considering it in film vs. video terms. On film, if you were to overexpose an image severely, you would get a very soft and gentle gradient or rolloff that would take your image from it’s darkest point to it’s lightest. The brightest parts of the image would blend into the darker parts almost seamlessly, and the overexposed parts of your image would still be somewhat pleasing to the eye.
On digital however, things are much different. A digital sensor will simply “clip” at a certain point, rendering any luminance values that exceed it’s dynamic range as pure white. So if you were to shoot that same image as I described above – rather than capturing a smooth gradient from dark to light, at some point that gradient would cut off and clip to white. It would ramp up towards the lightest part of the image, but would eventually clip, leaving you will an obvious line in the footage where the detail has completely vanished.
Take a look at this shot for instance, you can clearly see how there is almost a line in the brightest part of the image that separates it from the area next to it with detail still retained:
On film stock (or a digital camera with better highlight handling), the image would still eventually hit pure white, but the gradient would be much smoother.
Why Does It Matter?
You might be wondering why highlight rolloff even matters. After all, how often are we shooting into an overexposed light source, and will people even notice or care?
The truth is, so many of the shots you capture will likely have some clipping in them. Whether it’s a lamp in the background, a blown out window, the sky, etc. More shots than you think will have at least one hotspot in them, and the way those hotspots are handled can really affect the overall perception of your image… Even if those areas aren’t the focal point. They will still be seen and felt by the viewers, and the more natural and organic they look, the better the image as a whole will be perceived.
Saying that highlight rolloff doesn’t matter would be like saying shadow detail doesn’t matter. Neither are going to be the focal point of the shot (most of the time at least), but both will contribute heavily to the perception of the image by your audience.
Crafting beatuiful cinematic images all comes down to attention to detail. There isn’t one variable that makes an image cinematic… It takes several elements working in tandem to create the aesthetic that we all love so much. After all, if it was just one element that mattered – we would still be shooting 24p on DVX100’s.
Now that cameras have progressed to the point where even prosumer level gear can capture 14 stops of DR, the natural evolution will mean more camera brands will be focusing on improving their highlights. Personally, I’d pick a camera with a stop less dynamic range, but better highlight rolloff over the alternative any day.
Which Camera Does It Best?
Arri set the gold standard for digital highlight rolloff when they released the Alexa, but since then other manufacturers have been stepping up to the plate. RED for instance, has improved their highlight rolloff significantly over the years (although in my opinion Arri still has them beat), and they’ve focused on it for good reason. Professionals are demanding cameras that not only have high dynamic range capabilities, but can also harness that DR to create the most natural and organic looking image imaginable.
We are getting to a point where cost is no longer a barrier to entry for high end cinematography. In fact, some of the lower cost cinema cameras are delivering equal (if not better) DR and color science than far more expensive cameras. Take the Sony F55, The camera is an absolute beast and a true workhorse – but the color science and highlight rolloff in particular is notoriously problematic. That hasn’t stopped numerous productions from using it on major feature films, but even on productions of that magnitude the issues are noticeable and unavoidable.
So for the time being, if you aren’t planning on dropping your life savings and then some for an Alexa or Weapon, there’s another option in the market that may just be the next best thing: The 4.6K URSA.
As some of you know, I’ve had an URSA for a few months now and have really enjoyed shooting with it so far. When handled correctly, the image quality is really strong and it certainly has a filmic quality to it. That said, my biggest issue with the camera (other than the limited ISO range) has been the highlight rolloff. In fact, I would say the highlights are the biggest giveaway that my URSA footage wasn’t shot on an Alexa or a RED, as the image looks so great in every other way.
That said, with the newly announced 4.6K sensor that’s all about to change… Or so I think. Based on the footage that I’ve seen so far, the new URSA sensor seems to have some of the best highlight rolloff that I’ve seen on any camera under $15K. Take a look at some sample footage below:
Obviously it’s hard to tell just from this video what the camera is going to be able to deliver in the real world, but based on the footage (and my experience playing with it at NAB this year), I am feeling very confident about it. Personally speaking, I will definitely be upgrading my URSA to the 4.6K version as soon as I can for that reason alone.
There isn’t a single characteristic of any given camera that makes it more filmic or cinematic than any other camera on the market. It all comes down to the balance between sensor technology, lensing options, color science, dynamic range, highlight rolloff, and most importantly – who is behind the camera. That said, we’ve seen many aspects of camera technology improve drastically in recent years (namely resolution and DR), and now it’s time for manufacturers to step up their game with regards to highlight rolloff.
The good news is that as time goes on, more and more affordable cameras will offer great highlight handling. Right now the 4.6K URSA and URSA Mini offer some of the best results as far as more affordable cameras go… But over time, more and more brands will have no choice but to jump on board.