Exploring Dynamic Range: Part 1

It's time for a gear-centric tech geek post about the camera's ability to capture "dynamic range." For my purposes I simply define dynamic range as the range of luminance values in a scene and the camera's ability to capture those values. Dynamic range is of particular importance to architectural and interior photographers because we shoot under conditions where a single scene may have a large range of luminance values from dark shadow areas to bright sunlit sky.

There is certainly no dearth of technical discussion on the internet regarding camera sensors and dynamic range but many such discussions tend to become so far removed from the practicalities of real world image making that they cease to become useful. I am only interested in the subject of dynamic range in so far as evaluating cameras and techniques that may enable me to create the images that I want to create. I could care less about stops, charts, plots, graphs, bits and bytes.

Personally, I am interested in pulling detail from the shadows more than the highlights. I have never had much luck with recovering details from highlights. In the majority of the architectural spaces that I photograph, a properly exposed interior will almost always leave a grossly over exposed sky that simply cannot be recovered.

First off, let's start by looking at what some modern camera systems are capable of straight "out of the box." That is, just how much usable dynamic range is captured in a single shot. Once again, "usable" is a somewhat subjective term so your results may vary....

Example 1: Phase One P21+ medium format digital back. Though somewhat "dated" considering the recent release of top of the line digital backs such as the the Phase One P65 and IQ series and Leaf Aptus-II 12, the P21+ is a good example of what most "working class" digital backs are capable of when it comes to usable dynamic range.

Below is a shot of my living room on a late afternoon sunny day. No it's not usually this messy. I added some clutter for the sake of the image ;-)...Though overall very dark, some portions of the sky are still blown out beyond the point of recovery. This example represents a difficult lighting situation and yet the kind of dramatic light that I love to shoot in. I have included the Lightroom histogram for reference:

Here's the exact same image file adjusted in Lightroom. I've upped the exposure 1.25 stops and slid the fill light slider all the way to 100:

By upping the exposure I've overexposed some more of the sky, but it's really the shadow areas that I'm interested in here. Let's take a closer look at some 100% crops:

Pretty impressive. There is a bit of noise in the darkest areas of the fireplace but not much. Fine details are retained (note the sisal strand at the bottom right of the frame).

Example 2: Nikon D3x. As of this writing, the Nikon D3x represents the pinnacle of 35mm digital camera technology. The file it produces is unlike any other 35mm digital camera file that I have ever seen and is closer in quality and flexibility to medium format digital systems. Lloyd Chambers has an excellent write up about the amazingly clean files of the D3x. The dynamic range abilities of this camera is one of the few reasons why I have not switched to Canon as my primary camera system. As soon as Canon produces a camera that can match the base ISO image quality and resolution of the Nikon D3x I will switch.

Below is a grossly underexposed image of a client's library. I might underexpose an frame similar to this as an "insurance shot" to ensure that if all else fails I've got an exposure with no blown highlights (like the white orchid in the foreground):

Here is the exact same image file adjusted in Lightroom. I have upped the exposure three stops and set the fill light slider to 25:

Here are 100% crops:

Looks pretty good to me. There is no pattern noise of any kind and the noise that is visible in the darkest areas is random and looks almost like film grain. It looks like there might be some banding on the table but that is actually the striping of the wood. The texture of the leather couch can be seen in the highlight and you can eve see a seam in the leather at the bottom center of the image.

In future posts I'll test some more digital cameras and maybe even some film.