What is Dynamic Range?
Why is everybody so worried about it?
Over the last month or so I have been asked more and more questions about dynamic range, and I am seeing more and more articles and YouTube videos with headlines about this topic. Indeed, it is becoming the big buzz phrase in GEARtographer discussions all over the internet. I’m seeing people debating which cameras are best for dynamic range – debates about how much dynamic range is good dynamic range – debates about what is more important, dynamic range or a multitude of other camera features? etc.
But what even is dynamic range? And why is everyone so worried about it?
This is the point where some of you expect me to go off the rails and rant about dynamic range. Sorry to disappoint. For the most part – what I have been reading and watching about dynamic range is not wrong, BUT – and this is a big but- what is wrong is that in many cases we are not getting all the facts in these articles and videos. In most cases people that are reading and watching them are missing the most important context: the folks who are writing the articles and making the videos are telling you what is most important to them for their style of shooting.
So I want to take this time to give all of you some background on dynamic range and also a sincere recommendation on what I would encourage you to worry about more than dynamic range.
What is Dynamic Range?
The term “dynamic range” has multiple applications in human perception, music, audio recording, metrology and yes – photography.
Dynamic range in photography is not just about highlights and shadows, which seams to be what everyone talks about. In actuality it describes the ratio between the maximum and minimum measurable light intensities – in other words, the range of luminance values between the darkest and brightest perceptible points in an image. But unfortunately, dynamic range is a bit more complicated than dark and bright and highlight and shadow. Dynamic range also impacts your perception of color – because colors have a brightness, and when you can see a greater range of brightness, you can also perceive a greater range of color.
The idea of dynamic range depends on whether we are talking about a camera, an LCD screen or monitor, a finished print, or simply the subject itself as seen by the human eye. Much like color management, each element has its own dynamic range. That means that the concept of dynamic range that everyone is talking about is really only useful for a relative comparison between the actual scene, your camera, the image on the screen, and possibly a final print.
Okay – everybody breathe for a second – I am not going to get any more scientific than that for the sake of this discussion. I will spare you the talk of bit depth and A/D Converters and gamma corrections and tonal curves – all of which impact dynamic range. But we need to make some practical sense out of that definition that I just gave you.
Dynamic range Comparisons in Media and Equipment
Let’s do some comparisons… I am going to simplify the science a little bit here.
The human eye is capable of seeing nearly 24 stops of dynamic range in ideal situations.
Digital vs Film
Most digital cameras today have between 12 to 14 stops of dynamic range in their recording ability, with the latest and greatest like the Nikon D850 hitting a whopping 14.8 stops. Some video cameras reach even higher. Most modern film has a dynamic range of about 13 stops – which is a big part of why film shooters like film, and until recently that meant that digital cameras struggled to match the dynamic range of film.
Sony Vs. Nikon vs. Canon
BTW… since I know some of you keep score… The Sony A7RII only has a 13.9 stops. Heck, even my old school Nikon D810 has 14.8 stops.
Which means that if Dynamic Range is the most important thing for you, don’t buy that Sony A9. It only has 13.3 stops of range, and you know it’s bad when the Canon 5D Mark IV beats it with a measly 13.6. That’s a joke. Not the numbers – they’re facts. But dynamic range is NOT a reason to avoid the Sony A9 or a Canon 5D Mark IV – they are both great cameras.
But while we are comparing – we need to also compare computer monitors where we look at our images and or prints of our images.
The best monitors on the market today offer a dynamic range of about 10 stops. While there are some new 4K monitors that go higher, they also come with a price tag of nearly $40,000 dollars. So ten stops is what you are able to view on a computer. So we are already clipping away that 14 stop range of the Nikon D810 and Sony A7RII.
And if you are making a print of your photos… you could be looking at a dynamic range of 3 stops to 12 stops, depending on the viewing conditions. For prints, the real-world dynamic range is strongly affected by the ambient light. Prints that are viewed in darker settings will not yield as much dynamic range.
The lowest common denominator in this comparison was the monitor at 10 stops. So is there really value to having 14 or more stops of dynamic range when you’ll only realize 10 stops on your computer screen and possibly even less in your print?
SURE! There is value to having good dynamic range BUT – and here is my second big BUT for the night- not for the reasons that so many photographers like it.
Don’t misuse Dynamic Range
I am finding that so many new and young photographers like lots of dynamic range because it allows them to be careless. It allows them to not worry about the lighting ratios in the scene they are photographing. It allows them to not pay attention to shadows and highlights when they shoot because they can “fix it in post”.
It’s similar to the folks who watch my Fill the Frame video and respond by telling me that they don’t need to worry about composition when they shoot because they have more than enough megapixels and they will figure out the composition after they get the shot – “in post.”
I see so many photographers putting their subjects in the shade with a bright sky as a background. This is fine, as long as you realize the sky will be blown out and record as white. But then they use the dynamic range recorded in their raw file to pull the blues back into the image. And while it works, it looks fake. Cognitively, our brains expect the sky to be blown out. So what is the solution? Either don’t use the sky as a background or light the subject bright enough to match the sky. Proper planning will make this a simple challenge to overcome.
In other words… it is a growing trend of new and young photographers who don’t put in the effort to actually learn photography, and more importantly learn problem solving. They want the camera to do all the work for them or they are willing to spend a ton of time trying to be creative sitting in front of a computer.
As I’ve explained many times before: learning photography does not mean reading books or blogs and watching YouTube videos. Learning photography means picking up your camera, shooting, making mistakes, and shooting more and more and more.
So, in summary: should you learn about dynamic range and understand it ? In my opinion yes. Should it be the most important factor in your camera-purchasing decision? In my opinion, definitely not. What should you put a lot more effort into learning about instead of dynamic range?
In my opinion: depth of field. Yes, you heard me right– depth of field. I made it a point to ask several of the people who reached out and asked my opinions on dynamic range if they could tell me what three things impact and allow us to control depth of field. I also asked how we can use the focal point to control depth of field and sadly, the overwhelming majority of the people that I asked could not give me complete answers. Worse yet, they could not offer examples that showed they truly understood the concept.
When we are talking about all this physics stuff, depth of field is the one thing that can have the most dramatic impact on your photography and your ability to be creative in-camera. And NO – depth of field is not a blurry background or bokeh balls.
So I am sorry to those of you who thought I was going to create a scandal and rant about all those articles and YouTube videos. The thing that I hope all of you will take away from all this hubub about dynamic range is that you have to do the hard work. You need to take the time to learn about these things, NOT just listen to someone’s opinion and do it because they do it, but to actually understand the subject at hand. All of the photographers who wrote the articles and recorded the videos were telling you what was important to them – from their perspective, and for their way of shooting.
Like I always do, I just wanted to give you a little more background and context, and hopefully inspire you to take the time and learn more about dynamic range. I want you to decide for yourself how much it matters and, indeed, to learn more about depth of field because it is, in my opinion, the most valuable creative and technical tool that a photographer has.
And those are my Togthoughts for the week. Thanks for reading!
As always – I hope you find this useful. You can watch the rest of Episode #83 of TogChat in the video below.
And until next time, go pick up that camera and shoot something, because your BEST shot is your NEXT shot!