Factors To Consider When Choosing A Camera

Imatest is all well and good, but we appreciate that in his reviews, Matthew Allard has been doing rough comparisons of the dynamic range of cameras by exposing a scene for middle gray and looking for highlight clipping using false color. RED cameras have a built-in False Color Exposure mode that we use all the time, and if we ever shop for another camera (highly unlikely!), that’d be the very first test we’d want to do for ourselves.

The comparison is between the Z CAM E2-F6 Pro with a claimed 15 stops of dynamic range and the ARRI AMIRA.

Simultaneous dynamic range of the HVS

You’d think that dynamic range would be the number one consideration when choosing a camera for HDR, but not a few in the industry still repeat the fiction that any device that records log or RAW is enough, some even claiming that 10 stops DR is sufficient, which is factually incorrect.

The BBC writes, “Ideally HDR video should exceed the static dynamic range (i.e. the dynamic range that can be appreciated in a single scene) of the human visual system.” The simultaneous dynamic range of the HVS is said to be ~13 stops or more.

Sky UK, in their groundbreaking technical specifications for scripted UHD-HDR content, requires that cameras be capable of >14 stops. Of course, that would exclude all but one or two manufacturers!

Wide color gamut

Other considerations when selecting a camera are bit depth (preferably 12-bits or more) and the ability to capture saturated, accurate color at high luminances, something which not all high dynamic range cameras are capable of:

“The choice of the tiny color filters on the sensors—whether narrow spectrum or wide band—has a significant effect on the dynamic range and color saturation of the image captured. A wider-band filter leaves the sensor more sensitive to light, yielding a wider dynamic range and higher native ISO. But the color recorded by that wide- band filtered sensor is less true and less saturated.” – American Cinematographer Manual, 10th ed.

High frame rates

In the future, the ability to record at higher frame rates for select scenes will also be desirable, as motion artifacts like judder are exacerbated by today’s high contrast, high luminance displays; and according to Dolby, some colorists are even resorting to compromising their grades in order to mitigate the appearance of judder. Cooling then takes on even greater importance, as cameras can get very hot shooting at high frame rates and may have limitations due to overheating; they may also have to crop the sensor and record at lower resolutions in order to achieve high frame rates.