At the peak of fall foliage season the colors can reach fluorescent levels, by borrowing light from outside the visible spectrum and reemitting it in the red through yellow zones. Because of this, foliage photography requires careful editing to produce the type of image our eye recalls seeing. All too often people make the wrong adjustments, resulting in images that look false and unsatisfying. Lets look at a set of foliage photo adjustments, first by the numbers, and then tweaked to emulate the eye’s response, to see where photographers usually go wrong.
The Starting Point
Typically the camera is left to determine the best whitepoint, and to adjust at least one of the exposure parameters. The success of this varies with the subject matter, but often the result is not accurate, and the look is not ideal. In the image below, the default settings, when opened in Adobe Lightroom 4, produce a flat image, with insufficient color. Keep in mind that no color adjustment should be done to images without first calibrating your display.
Other elements in a fall foliage image still need to be correctly exposed and white balanced, for instance the twigs in this macro can’t be too red or too saturated, or the overall believability of the image will be lost. The best starting point for correcting camera settings for any image is with the SpyderCube. For this image the adjustments from shooting the SpyderCube in another frame earlier in the series are applied to the image. The camera default settings in Lightroom are shown next to the Cube-adjusted settings in the image below.
These settings increase the dynamic range of the image, making the midtones more dense, the shadows and blacks darker, adding punch to the image. Too often the assumption is that lightening fall foliage will make it “brighter” when the actual result is to make the colors weaker as they get lighter. Often, careful deepening of the midtones actually intensifies the foliage colors, as well as increasing the punch of the image as a whole. Note that the whitepoint of this image was fairly well estimated by the camera, so the color change caused by whitepoint correction, which can sometimes be quite significant, is minor in this case. The image below shows the result of applying these adjustments to the same photo.
Camera Color Correction
Before making any visual adjustments to the image color, it is best to make global color corrections for the camera used. In this case I now applied a SpyderCheckr color calibration for this camera. The change to the image is subtle, and actually reduces the color saturation of the red channel, which is technically correct; but not necessarily in line with the artistic intent we have in mind for this image. Here is the SpyderCheckr adjusted version of the image below.
Now that the dynamic range, white balance, and camera color have been corrected, I can make further adjustments to bring out the fluorescent nature of fall foliage in the image, while feeling comfortable that the overall corrections of the image will be in-line with the other images from the shoot that will be used in the same series. The lazy solution for fall foliage correction is to simply increase the global image saturation with the Saturation slider. However, many fall foliage images include greens and other colors, which will have their saturation increased along with the foliage colors, resulting in an image that the eye immediately sees as false.
The preferred solution is to adjust the saturation of the foliage color channels, while keeping an eye on the realism of the resulting image, and watching out for possible posterization in color transition zones. The image below shows a closeup of what happens to out of focus areas with color transitions when the changes between adjacent channels are excessive, and gradients posterize. The version at the bottom shows the final choices, which minimize this posterization. Note the reduction in banding around the green area.
The next consideration is out-of-gamut colors. Its easy, when attempting to create the type of fluorescent results fall foliage can produce, to exceed the gamut of both your display and your printer. Gamut warning tools can be helpful in avoiding this situation, but the eye is the final arbiter. If further increase in the saturation of a color does not actually increase its saturation, and perhaps causes other side effects instead, then you are working outside the gamut of your display. Reduce the saturation increase you are producing until you can distinguish saturation changes with each slider adjustment.
Below are the SpyderCheckr HSL adjustments on the left, with the tweaked saturation settings on the right. These tweaked adjustments are only to the saturation sliders, and only for the red, orange, and yellow channels, where fall foliage colors occur, plus adjustment to the green channel to smooth color transitions. Avoid excessive green increases to keep the image believable. If your foliage was shot at a long distance, especially through humid air, then global increases to saturation, contrast, and sharpness may be needed to compensate for atmospheric perspective effects.
Below is the resulting image. It has been converted to sRGB for the web, so not all colors desired for inkjet output can be included in the images shown here. But the general result of correcting dynamic range, whitepoint, camera color, and foliage fluorescence, instead of simply increasing the saturation slider show even in the sRGB version of the image. In order to print this image, I would now move on to using Lightroom 4’s softproof function, to work with the capabilities of my printer, ink, and media combination as described by my SpyderPrint output profile for the combination.