The Final Steps in Post Processing an HDR Photograph in Adobe Photoshop
After HDR processing our original bracketed photographs into a single HDR photograph, I find that the photo is usually does not match my vision. Just about every HDR photograph ends up spending a little bit of time in Photoshop. I tend to consider the HDR photo as a starting point, and I use Photoshop to process this photo just like I would process a non-HDR photo. This article is not meant to be a step by step tutorial on how to use Photoshop. There are plenty of those out there, and YouTube is a tremendous resource for finding great video tutorials. What I am going to do is explain the approach I use to solving a problem with a photograph. The types of things that I typically do in Photoshop:
- Clone out any distracting or unwanted elements
- Using Topaz Adjust to restore life to the image
- Color Adjustments
- Dodgeing & Burning
- Removing any unwanted noise
- Sharpening
In many photographs there are items that are unwanted, or distracting. When I shoot I try to do everything that I can to remove these unwanted items, but sometimes there is just nothing that you can do. I always start off by removing these distracting or unwanted elements. This can be as minor as removing some sensor dust, or as major as removing a telephone pole and its wires. I create a new layer and use a combination of the Healing Brush. This tool is unreal, and almost always fixes my problem exactly as I would hope. If it doesn’t, I simply run it a second or even a third time. On occasions, I will follow up with the Clone Tool to get things exactly as I want them.
Photos that come out of the HDR process often have a flat, washed out look to them. They lack a little bit of life, and seem dull. There are several tools that can be used to fix this, from the Levels tool to the Curves tool. I prefer to use a plug-in called Adjust from a company named Topaz. Adjust does some amazing things, and I barely tap into the power of this software application. I use it simply to restore life to a photograph. I create a new layer, apply Adjust as a filter and go through all of the presets til I find one that restores the photo to about where I like it. Once I find a preset that gets me close to where I want to be I will play around with the sliders to get it exactly what I want. I start at the top and adjust the sliders just like when we used Photomatix – simply slide the slider while asking yourself the simple question “Is this making it better or worse?”. Once I am happy with the adjustments, I exit the filter to return to Photoshop.
Once back in Photoshop I like to perform my color adjustments and corrections. This is done in two stages – global adjustments, and local adjustments. I will often add a Vibrance Adjustment Layer that I will use to increase the amount of the colors in the photograph. The Vibrance tool is very different from the Saturation tool in a significant way. The Saturation tool adjusts ALL of the colors in the image, either increasing or decreasing the intensity of the colors. The Vibrance tool does NOT adjust all of the colors, but only the colors that are not already saturated. It is much more subtle, and in my opinion has a much more pleasing effect on the image. I tend to apply the Vibrance Adjustment Layer as a global adjustment meaning that the effect is applied to the entire image.
At this point I will typically use one or more Saturation Adjustment layers in a very targeted way – to correct or adjust one color at a time, in an isolated location of the image. For example, many times the chrome and shiny metal will pick up a hint of color from the processing, causing a shiny chrome bumper to have a slight green tint to it. I will use the Saturation Adjustment Layer to decrease the saturation of only the green color. This might have the undesired side effect of reducing the green in the grass, Photoshop has an amazing tool called Masks that allow us to apply this reduction in green to only the chrome, leaving the grass unchanged. I will continue to repeat this process to increase or decrease the saturation of individual colors throughout the photograph.
Dodging and Burning are not a technique from the digital world, but have their origins back in the days of the dark room. When you Dodge something you are making it lighter, and when you Burn something you are making it darker. Many peoples first thought is that you would Dodge (lighten) a dark area, or Burn (darken) a light area, but this technique can be just as useful the opposite way around. I use this second technique to help increase contrast in a very controlled way. For example, I will do this to help enhance the texture in rocks along the seashore. By making the light areas a bit brighter and the dark areas a bit darker, it helps the texture in the rocks to pop off of the image a bit more. It is important to understand that this is done in very, very tiny amounts. So tiny, that I often cannot tell where I have made things lighter and where I have made things darker. I actually have to toggle the layer on and off to see how the dodging and burning is effecting the photograph. Another example of applying this technique is when I photograph the sea. I love to dodge the whitecaps just a bit to help them stand out in the darkness of the sea a little bit better. The applications of this technique are really endless, and you will find that dodging and burning is performed in just about every kind of photography imaginable The technique that I find works best is to add a new layer, fill that layer with 50% grey, set the layer blend mode to Overlay and then painting with a white brush to dodge and a black brush to paint. I often set the brush the opacity to a value between 3% and 7%. Subtle is your friend, and I will make many brush strokes over the same area gradually building up the effect.
All photographs have some amount of what is called Noise in them. Noise appears in a digital image as what appears to be a grain, and it appears in all parts of the image. I often see that it is most obvious in the sky and in the shadows of the photo. The HDR process tends to introduce more noise to a photograph then other processing techniques, but it is something that can be dealt with relatively easily. I use another product from Topaz called DeNoise that does a great job of removing the grain, but preserving the underlying detail so that the image remains sharp. When you reduce noise from an image, you tend to lose some of the detail in the image. I find that it is often helpful to reduce the noise in a photograph in sections. I might apply a lot of noise reduction to the sky, and then use a layer mask so that the noise reduction is only applied to the sky. This allows me to reduce the noise in the troublesome locations of the photograph, but maintaining the details in other parts of the photograph.
The final stage of processing is to sharpen the image. Sharpening helps the edges of objects to appear clearer and crisper, making the object appear to have a sharper edge. There are many techniques for sharpening a photograph, but when I sharpen an HDR image I tend to prefer to use High Pass Filter. I like my HDR images to be a bit sharper then a normal image, and I feel that this approach gives me the results that I am looking for. Sharpening an image tends to introduce some unwanted artifacts, such as noise and halos around objects. I will often use a layer mask to selectively apply the sharpening to only important areas in the image. I will often mask out areas such as the sky and the ocean, simply because that is what I like.
These techniques cover the majority of the development work that I will perform on a photograph. These techniques are NOT the only way to go about performing these changes to a photo – there are many ways to do things in Photoshop, and very often one way is as good as another. It simply comes down to a technique that you are comfortable performing, and that helps you to create the photographs that you want to create!
The key is to experiment to find techniques that work for you, and how you like your images to appear.