Your camera's dynamic range

The objective of this exercise was to measure the dynamic range of a camera.  I tried to find out via the internet what the official dynamic range of my Nikon D5000 is and this varied between reviewers.  I also realised from my research, and from completing this and the next exercise, Scene Dynamic Range, that it varied depending on the lens being used (as the end of scale readings are limited by the lens) and also the ISO used.  I think on average my camera is capable of reading a scene of around 8 stops and producing reasonable results.

Unfortunately the time of year where this exercise fell in my schedule was in December 2013, which was dark, gloomy, wet...very little opportunities for high contrast photography unless of course the days of bright sunshine when I was in the office! :(

So, eventually a day came with the right lighting: 29 December 2013.

Here is the initial shot of the scene (first image below), with High ISO NR turned off.  Note that Active D-lighting was set to High (I later turned this off from my basic settings as I discovered that this was the factor affecting noise performance!).  All images were set to ISO 100 and shutter speed: 1/750s, thus allowing the aperture to adjust and calculate the dynamic range.  For this exercise I used my prime 35mm f/1.8G lens.  The scene was shot so that the highlight clipping only just started to show (see second image below), resulting in the exposure being 2 stops underexposed from the average reading calculated by the camera on matrix.

I then switched to spot metering and measured the brightest and darkest patches, by moving in close:

I found that in the brightest area, the aperture adjusted to f/11 and in the darkest area to f/1.8 (which is the widest the lens will allow).  Referring to this website's f-stop table (accessed for reference on 26 January 2014) this scene had a dynamic range of 5.22.

Looking at the point sampler (pixel value) in my NX2 software, the highest value I could find in the shiny patch on the car was 252.

Same image with brightness adjusted until dark details are visible; no noise or conflict between dark and noise present, but the image is now clearly too bright!

Although zoomed in to 100% magnification, you can clearly see that there is noise!

All in all, the dynamic range was smaller than I expected.  But, the lower end was limited by the lens, and the upper end might have been higher, had I used a faster shutter speed.