Exercise: Your camera's dynamic range.

Outline: Undertake a series of instructions to determine the dynamic range of your camera.


Using my Canon EOS 1000D,  I managed to take this image on a sunny afternoon (yes, sunny days can be very sparse in Wales).

ISO 100 F13 1/500 -1/3exp

There is a good scale range from bright white door frames to deep shadowed windows. My camera was at the lowest ISO setting of 100 and on an auto aperture/shutter speed setting to allow me to gather the measurements of the separate areas in the image. I used the wide angle lens to take the image and then zoomed into telephoto focal length using the center weighted average setting to pin point the measurement of each position.

These were the readings taken of the scene. There is a vast range of aperture and shutter speed values shown indicating the differences in the levels of brightness.

Using photoshop elements 9, I then zoomed in to 100%, as requested in the exercise, and focused on the white area above the door.

Here we can see, in the pixel value sampler, that in the white area, the values are 215 in each of the three colour channels.

I chose the shadowed area in the glass door to highlight the shadow values. It has detailing through the 'reflection' but there are also some areas of noise.

Here, the values shown are a lot lower, down to 6 and even 4 in the B channel.

Given the normal lens aperture range, my camera's dynamic range has a healthy 9 stops. The brightest white area is measured at F14 (1/500) and the darkest shadowed area is measuring F6.3 (1/100) so in aperture AND in shutter speed values we have 9 stops difference:

Aperture: F6.3, F7.1, F8.0, F9.0, F10, F11, F13, F14
Shutter Speed: 1/100, 1/125, 1/160, 1/200, 1/250, 1/320, 1/400, 1/500

Conclusion: I think this was a great and simple exercise to explore the subject of dynamic range and also, for me, about learning more about the qualities of my camera. This course is proving to be a great insight into the basic areas of using the camera properly and also of the systematic way of taking images and editing them. As a beginner to digital photography, I find simple yet effective exercises like this one a really good way to learn.