Sensors: The Reality of Dynamic Range
Should you really buy a large sensor digital camera because it has more dynamic range?
Let’s find out!
Reality Check
Today, it is time to address a statement we hear all the time: “Small sensors are fine, but their dynamic range is so limited. You just need a bigger sensor for sufficient dynamic range.”
But is that really true? Time for a reality check!
To answer this question, we have to consider two aspects:
1. How much more dynamic range does a bigger sensor provide?
2. Is the advantage significant enough to impact our photographic practice?
Sensors Compared
Probably the best independent source for the photographic dynamic range of digital cameras is photonstophotos.
Let’s compare what different models are able to capture at their respective optimal ISO settings – get ready to have your mind blown:
Nikon D2H – 7.01 Stops
Canon EOS 5D Mark I – 8.34 stops
Olympus OM-D M5 – 9.27 Stops
OM System OM-1 – 9.54 Stops
Canon EOS 5D Mark IV – 10.83 Stops
Sony A9II – 10.9 Stops
Nikon D800 – 11.42 Stops
Pentax K-1II – 11.6 Stops
OM System OM-1; Live ND64 – 12.01 Stops
Fuji GFX 100 – 12.3 Stops
Phase One IQ4 150 MP – 13.33 Stops
Not counting the worst of the bunch, the Nikon D2H, which I just threw in there because I really like it, the differences are not huge at all!
Nikon D2H
The “Grandad”-category cameras 5D and D2H capture 7 to 8 stops.
MicroFourThirds, the most compact professional camera system on the market, delivers around 9 stops.
Olympus OM-D E-M5 I
With a 35mm equivalent cameras, you get about 11 stops.
In digital medium format, only the high-end Phase One backs give you anything above 13 stops. That is as good as it gets right now, for only 42.000 Euros without camera and lenses.
In Practice
An evenly lit subject requires 4 stops of dynamic range, even the Nikon D2H can handle that easily.
The most extreme lighting ratio I’ve ever encountered on set was 32:1. To capture the full tonal in such a situation, 9 stops are needed. The OM-D M5 is good enough for that. Granted, it is a really good camera, although an eleven year old one.
Canon 5D Mark I
The HDR Challenge
Mostly in landscape and architecture photography, subjects can require more than 9 stops.
So if you run out of dynamic range, you have bracket and combine the images in post using either tone mapping or exposure blending.
Here are some considerations:
1) Of course, there should be little to no subject movement. Is that a problem? Not really, as buildings and mountains very rarely move a lot.
2) In order to get a high quality HDR image, the dynamic range of the individual shots have to have some overlap. With new cameras, a step size of 2-3 stops works fine, but with old digital cameras, the bracketing steps have to be around 1 stop. This can be a bit tedious, but it is definitely doable.
Having said that: with the Nikon D2H – which was really never meant to be a high dynamic range camera – a 9 frames bracketing burst will give you 15 stops of dynamic range. Take that, Phase One with your measly 13 stops!
High ISO
What about low light photography? Isn’t it true that you loose dynamic range when raising the ISO.
Yes, that is true, but when do you shoot high ISO? When you want to freeze motion. This is usually in reportage or some kind of action photography. Very rarely you need more than a few stops to capture the full tonal scale of your main subject in these situations.
With a camera that has less than 7 stops of photographic dynamic range, this can be a bit annoying and you might want to bring a flash. Everything above that: You are fine.
Nikon D800
Conclusion
Larger sensors deliver better image quality. It is debatable whether this image quality is really necessary. Be that as it may, if we just look at the dynamic range, we have to ask ourselves the question:
Does the Difference Make a Difference?
Under normal circumstances, eight stops are plenty.
If you are dealing with an HDR scenario and you want to capture it, you have to either shoot multiple exposures or use something like a graduated ND filter. And that is just the reality of it.
The difference between a 40.000 Euro Phase One digital back and a 100 Euro Nikon D2H from 2003 is around eight shutter actuations. And the Nikon D2H has a very durable shutter unit, so don’t worry about that. I would worry more about having 146 MP less.
Fun calculations aside, you should definitely not buy a stills camera because it has one or two stops of dynamic range more than the other one. This just does not make any sense.
