Color & Quality
In the age of film photography, our habit was to buy the film, load it into our camera, shoot the picture, roll the film back into its cassette and take it to the film lab for processing and printing. As you can see form that particular workflow, much has changed in the era of digital photography. Now we buy the storage card, stuff it into our camera, shoot the picture remove the storage card and download the images to our computer. We are now the processing lab.
The one thing this new workflow has not changed is the demand we place on image quality and color fidelity. The photographer is now responsible for both. Those two qualities of digital photography are no different from film photography. What we have to look for (and hope for) is that the camera we purchase presents us with as few difficulties in attaining the level of color fidelity and image quality that we desire.
When looking at our three cameras we see one very noticeable difference. Regardless of the ISO setting on the Nikon D5000, the images appear underexposed, by at least one half of one ƒ-stop. The images are all darker than the same image taken with the Canon or Olympus. At first we thought that we had somehow incorrectly changed the exposure compensation, i.e., having the camera purposely over- or under-expose an image. This is not the case. The meta-data confirms that there is no exposure compensation.
This "under-exposure" gives the images a dull appearance. The colors are not what we remember from the moment we created them in the camera. They lack that fidelity of the moment of capture. This does not mean that selecting the Nikon D5000 is a problematic choice. It does indicate that there are some misgivings to explore.
One of those misgivings is how the images show the bright blue sky and how a Macbeth ColorChecker appears when we examine test images. We took pictures of the Macbeth with each camera and stepped each camera through its range of ISO settings. Our other images were all captured at the nominal lowest ISO setting, in the case of the D5000, ISO 200.
At ISO 200, the D5000 indicated a signal-to-noise ratio of 5.23. This high a noise level is not acceptable for a camera in this price range and feature set. To confirm our test results, we looked at the signal-to-noise values for ISO 400 and ISO 800, with similar or lower results.
The Canon T1i exhibited significant improvement in color fidelity and image quality over the D5000. All the colors seemed to be just a bit too bright, yet much closer to what they should appear like.
Skin tone and the primary colors found on the Macbeth were markedly closer to the test target. When we examined the test target images for noise levels, the Canon generated a value of 3.42, much improved over the Nikon.
The Olympus E-620 showed even greater improvement, over both of the other cameras. It did appear to us that this was the perfect case of the Three Bears: One to dark, one too bright and one just right.
All the colors on the Macbeth appear, as they should be. In particular, the sets of primary colors (RBG and CMY) ring true. The E-620 has a noise value of 2.02. While this value does not place the E-620 in the same category as a pro-sumer or professional camera, it does make the photographer's life a little easier.
Why easier? Because, it goes back to our statement at the beginning of this segment. You are now the lab technician that is responsible for correcting the faults we find in our images and making them look good. All the problems with the Nikon and the Canon can be corrected in your favorite image manipulation program. We make us of Photoshop; it remains the ultimate tool for our needs. Of course, even the pictures captured with the Olympus will require some small amount of work. But that is the operative word, small. You may need much more time to clean up an image from the Nikon, but you will need less time for the Canon and even less time with the Olympus.
For Color and Quality we would rate the Olympus E-620 at 4.5, the Canon T1i at 4 and the Nikon D5000 at 3.