Comments On Color


It turns out that color in digital photography is a rather tricky thing. You may be aware that professional photographers spend quite a bit more money on the monitors for their computers than the average user and use sophisticated equipment to calibrate them as well. This in itself should be a tip-off that color is not an easy thing for a display manufacturer to get right. General consumer-grade displays sometimes get the color pretty close but too often it is noticeably wrong. It must be admitted that our expensive smart phones frequently fall into this category. We fretted quite a bit about the blue tint our first smart phone imparted to these pictures. Then, next year, we looked at the pictures on another phone from the same manufacturer and the color was too yellow!

What it is important to realize here is that it is not unusual for a device manufacturer to do some supplier-hopping depending on who currently has the best price on electronic components. This goes for the fairly expensive and color-critical display as much as any other component. As a consequence, there is no way to predict what kind of color imbalance might exist in the future. So much for our initial idea of toning down the blue in the pictures to make them look right. Notice that this also means we are all pretty much stuck with "The Luck of the Draw" as to whether color will look correct on our particular device. The good news is that things have improved a lot in the years since we first wrote these comments on color. We also admit that we are probably way more critical about color than most people.

Another interesting color issue is the case of the color "violet." If you have ever looked carefully at a rainbow, you may have noticed that violet's position is "outside" of the blue band (that is, on the opposite side from the rest of the rainbow.) This is a critical observation because in a digital world the colors of the rainbow are re-created for our eyes by mixing the output from red, green, and blue filters corresponding to the original red, green, and blue phosphors in the picture tube of a color television. With this setup a reasonable facsimile of any color between red and blue is possible by mixing these three primary colors in the correct proportion. However, the rainbow tells us that violet cannot be created by any mixing of these three colors - it is "outside" of their range of representation. So, what happens when you photograph a violet flower? The camera will mix the red, green, and blue as best it can and come up with the closest possible solution: straight blue.

A related issue is the observation that many people do not carefully discriminate between the colors purple and violet, but in reality, they are two very different things. The color purple is a secondary color formed by mixing red and blue, but violet is itself a primary color out beyond blue (in the same way that the invisible color ultraviolet is out beyond violet.) Thus, two flowers sitting side by side, one purple and one violet, might be perceived as looking very much alike. However, a picture of these two flowers will show a huge color difference, one purple as it should be and the other a startlingly incorrect blue!

On the other hand, we once took a picture of a rainbow with an older digital camera and the picture shows a faint color outside of the blue band. Is it violet? Too our eyes it looks purple. One thing a camera manufacturer could do is to make use of our tendency to not to discriminate between violet and purple and let a little violet light "leak" through the camera's red filter. If done carefully the camera could fool us into thinking we are seeing the violet in a rainbow by giving us a bit of purple. Pretty ingenious but not what we actually see when we look at a rainbow. By the way, this particular camera tended to render a blue sky with a tinge of purple, so if that was the manufacturer's intent, they still had not got it quite right.

Finally, there will always be some variation in the hue of a picture dependent upon the light available at the time the picture was taken. One reason studio pictures look so good is that the photographer has absolute control of light in the studio. By contrast, one of our goals has been to do flower photography "in place" if possible. Another goal has been to use natural lighting and consequently we try to avoid overuse of the flash. This means that when we're working in a shady area the pictures can have a pronounced blue tint. It is probably worth mentioning that this blue tint is not wrong. The light in a shady area really is blue and the camera has faithfully recorded that. We tend not to notice this because our eyes adjust to situations and let us see colors as we expect them to look.

When the color in a picture looks wrong, we use computer software to attempt to correct the tint. However, if the color of the original photo is really off there are limits to what can be done. In some cases we have been forced to use pictures that are less than optimal. This has usually only been the case for plants that grow in difficult situations. Perhaps someday we will get around to re-shooting some of these pictures. After over twenty years, the flower web site is still a work in progress.




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