Avoiding Some Common Photoshop Problems

Avoiding Banding
In the real world, banding doesn't seem to exist. Because of the infinite complexities of light moving through air, bouncing around, and eventually moving into our eyes, all gradients of color seem to be smooth. That is until you see them on a press sheet. If you have experienced the nightmare of strong banding on a printed press sheet, you understand the problem. For those who haven't had to deal with it, here are some pointers to help you avoid it.

The most common cause of banding is the use of gradient tools in photoshop. By using the Gradient tool, you are almost guaranteed to create an obvious banding of color somewhere in your gradiated range. Unless you really know what you are doing, and are an experienced professional, I cannot emphasize strongly enough how unwise it is to use the gradient tool for a job that it going on a press.

After that, the biggest offenders are "Gradient-Like" tools. These include Heal tool, as well as the Blur filter. Each of these works by finding the difference of color between two areas and gradiating the space between. Although each works very differently, they have the same result when used with extreme settings. Personally, I think the Heal tool is an incredible instrument. But, to avoid banding with Heal, it is critical to keep your brush size small. When blurring, try to avoid large selections with large values for blur settings. Using a blur size that is more than 10 or 15 pixels, even on a very large image, will normally cause banding issues.

Image Haze
Sometimes the difference between a great picture and a good picture can be almost nothing, often a change to a curve that when mentioned seems almost meaningless. Nonetheless, there are some very simple adjustments that you can use to make your pictures pop on press.

Keep in mind that Film Print Paper, and high-quality sheets for Epson and HP inkjet proofers are not like the papers used in offset printing. If you have bought them, you know how expensive they are, and how carefully they must be handled. Press papers, on the other hand, are significantly cheaper, tougher, and more versatile, but less vivid. It's just the nature of printing. Knowing this, you'll understand that all pictures that are destined for the press should be "punched up" a little. Add 3-5% more contrast and saturation than you may be willing to do for an inkjet or a photo print.

Another factor to keep in mind when trying to eliminate haze, or resurrecting a "dead" photo, is the color blue. Just as we use haze and skylight filters to take the blue out of our photographic shots, we can continue that process in Photoshop. By simply using Curves to reduce 2-4% of the blue from the midtones of your pictures (cyan, if you're working in cmyk), you will immediately notice two things. First the images feels warmer and move vibrant. Second, it seems to have more "pop" to it.

Blown-out Highlights
If it's a problem in the darkroom, it's a problem on press. And blown-out highlights are no exception. The mark of a good technical photographer is his skill in making the darkest and lightest areas (Zone 0-2 and 7-9, if you're an Ansel Adams student) show up in a pleasing, meaningful manner. It's very important to make sure that your work in these areas doesn't lose all of its detail. In order to avoid such a fate, here are a couple of hints that will help.

Work with your Histogram visible. Whenever you're doing color correction, it is absolutely imperative that you keep an eye on your histogram. Without it, you simply will not be able to tell when you have pushed an image too far. Also, it may give you some hints as to when you can push it even further. Make sure that your colors aren't "stacking up" on the ends of the histogram, and that none of your color moves push the edges of the graphic onto the edge of the histogram.

Use Curves. Force yourself to work with curves and only curves on your next few color corrections. In theory, using just curves should allow you to exactly duplicate the look of the scene in which the picture was taken. Also, bending your curves will generally keep your color moves at the dark and light ends of the spectrum more subtle.

Avoid some adjustments. We all started out in Photoshop using Brightness/Contrast and Levels to make things look better. But, the truth of the matter is that these controls are generally fairly destructive to the lights and darks in our images. Avoid them at all costs. Learn to use other tools that are less brutal.

Fake it. If your picture is blown out, no amount of "correction" is going to fix it. You need to simply draw the data in that doesn't exist. Do this by creating a new layer above your old layer and carefully drawing in using a light grey for b/w images, or a very light appropriate color for rgb images. Make sure to use a soft brush. On top of that, add noise to that area, carefully experimenting with the noise slider until the noise density is a good match. Finally, scale back the layer's opacity until your correction starts to feel natural. You haven't eliminated the problem of lost data, but you have eliminated the glare spot without being obvious.