Manip Academy #9 : Adding realistic highlights

So you're looking to have a dramatic light effect in your work and aren't sure how to go about it... In Photoshop there are always many ways to reach your goal, today we're going to focus on adding highlights by using the Color Dodge layer mode.

This is a fairly easy effect to produce realistic light hitting a surface. This method works best when you're working on mid/low range levels and with elements that don't have extreme contrast. It does very well when you have a shaded element and want strong highlights but might not work in other circumstances.

If you want to practice with this same tent, feel free to download this PSD (tree stock and original hilghlights layer included): Adding Highlights Turorial PSD

Background, layer and brush preparation

Adding highlights is something you usually want to do towards the end of the process. If you're going to add high contrast highlights to an element with this method, it's best to not allow this element to have many bright surfaces. In this case, my tent looked pretty bland beforehand. I had already set up the main lit (left) and shaded (right) areas, but with low contrast between them, so that the highlights will have a greater impact.

Created a new layer and set its mode to Color Dodge, then lowered the Fill to 62%. The way Color Dodge works, if you set a bright-ish color for it, with the layer at 100% fill whatever you paint is likely to look white, but when you lower the Fill it starts letting the color in while it lowers the intensity. So 60% is around my usual starting point for the Fill, you can adjust at your taste. I didn't need a lot of color for this one, so I chose #fafae9.

I picked up the default round brush and modified it to fit my needs. I set the hardness to around 50% then I flattened and rotated it to adjust better to the incline of the surface of the tent. I set Opacity to 100% and Flow at 10%.

Painting

Before you start painting, try to imagine how the light would hit the surface you want it on. Check where the light source is, and try to create a 3D image in your mind of where it should touch your element, have some reference at hand if possible. One of the things that make your image believable are often the contrasts, in this case light and dark, sharp and soft edges. I don't worry about the sharp ones for now, just pick up the brush and start painting.

I know that the leaves are usually moving so the soft edges and half opacities are good in this case, I'm also thinking about the wrinkles in the cloth as I paint, which are going to have most of the hard edges later on. I remade it (below) for this tutorial so I could show this step.
As is, most of the highlights are nearing 100% opacity, the color and intensity differences are given by the tent underneath in conjunction with the Color Dodge.

Refining

On the next and last phase I used mainly the Eraser, but also the Smudge and Blur tools. I prefer the eraser to making a mask for this because I can paint on areas that I've erased again if I'm not satisfied with the result, while a mask would hide those areas permanently. I also like to have it all only on one layer so that I can cut and transform easily.

Keeping the 3D image in your head, imagine where the shadows would be according to the position of the light source and start subtracting light. Since they are separate light spots, in this case we can select one and work on it without affecting the others. I used a hard Eraser brush for details and folds in the fabric, and a soft one with low opacity for parts that transition into shade. The Smudge tool with a high setting (50% or more) works well to extend some edges of light through the wrinkles, and the Blur tool can help if you're cutting part of the layer to move it.

The result on this one is a bit sloppier than the original, but I hope it works as an example:

Using photos

The same process can be applied by using photos. Here I picked up this picture I took of a tree and found the area I thought would work best for this effect. We are keeping the sky, so to get rid of the leaves I used the Magic Wand on the sky, inverted the selection and deleted the leaves (you don't need a very precise selection for this). Made this layer a Clipping Mask of the tent's layer. I enlarged and rotated the leaves until I found the right position for them, and with Hue/Saturation, tried to give them the same color I had used before. I made a mask and painted out the parts that were off limits (I have left a trace of them in the image so you can tell what was cut out).



Now if I set the highlights layer to Color Dodge and lower Fill to 63% the whole thing starts picking up. I felt like there was too much light so I re-selected the sky and thickened the shaded parts a bit (Select/Modify/Contract) and deleted the extras. The light edges are so sharp now, so I prepared a selection to Blur them. To do this, and to get a more realistic feel to the blur, I made a New Layer, filled it with white, and created a Layer Mask for it. On the Mask, applied Filter/Clouds with pure white and 50% gray, then applied the mask. This is to give the blur some intensity variation, you can also increase the clouds' contrast a bit for sharper difference.

I Ctrl/Cmd+clicked on the layer's picture and made a selection with the clouds layer, then hid the layer altogether. With the focus now on the Highlights layer, I added two rounds of the same Gaussian Blur (ratio 2 worked for me cause I'm working on a small canvas, you will want to find your own numbers). The highlights look pretty decent now, but they are still flat on the tent, so I tried some Warping to adapt it to the shapes of the tent.



The last step does require some more refined touch. If you're working with a mouse, I highly recommend selecting individual parts of the highlight, so that you can work on it without messing any others up. By selecting them you can also use a mask instead of the eraser, translating my Eraser settings into normal Brush settings will do just fine. Remember what I did most of here is deleting and then some smudging, cutting and transforming. Work with low opacities and hardness for smooth transitions and high opacity/high hardness for creating sharp edges.

I re-worked this one with the mouse myself for this result. You'll probably notice that while all these in the tutorial have more detail, the original does in fact look more realistic. That is because when I was first creating it I spent more time on thinking about the perception itself than the technique, which is more what I was trying to show here. Specially if you're painting it, keep always in mind that the final result is more about the image you've made in your mind than what skill you have with the stylus.

I hope this tutorial was useful, it's my first one ever so feel free to give me tips/critique. Also, if you have any questions don't hesitate to post them in the comments.