Do you mean just the round headlights, or the whole beam?
Either way, one really good way would be to use a curves adjustment layer. I'm not sure, though whether every version of photoshop works like this? I use CS5. Anyway, here are some steps.
1. Make sure the layer is not a background layer. If it is, double click it in the layers panel to turn it into a "normal" layer.
2. Make sure you have the Layers panel visible (see window>layers).
3. Look at the bottom of the layer panel. You'll see a half fill in circle. Click this to create an adjustment layer.
4. Choose "curves".
5. This should bring up a little graph in a window labelled "adjustments". It should create a new layer showing a graph symbol and a white rectangle. This white rectangle is quite significant. It is a mask, or "map" of that layer. You use it to apply the adjustment ONLY to the parts of the mask which are shown in WHITE.
6. Now bear with me, and take time to use a bit of trial and error here. Remember, you can always delete the layer (or mask) and start again.
We are first going to adjust the curve to suit JUST the headlights. Then we are going to use the mask to erase everything EXCEPT the headlights so that the rest of the picture goes back to normal.
7. So play with the curve adjustment until the headlights are how you want them. The rest of the picture will change too, but we'll fix that in the next step. Try moving the top right part of the line to the left. This will dramatically lighten.
8. If you're happy with the lighting for the headlights, we now want to set the mask so that it does NOT apply to the rest of the picture. Remember, white means "include", black means "exclude".
Click on the white rectangle mask. You now need to choose:
a) Paint black everything except the headlights
OR
b) Invert the mask (click ctrl-I) and paint in white to get the headlights back in. This would be my recommendation.
It can be disconcerting to be painting in black/white and only see changes in lighting! If you click on the layer thumbnail instead of the mask you WILL be, so take care (there;s always the Undo key!)
9) As you paint, you see the results live.
Notes on painting the layer mask:
- Painting is not just painting in one thick stroke. Painting can mean using gradients, patterns or anything. What I think you will need if you're doing a beam (rather than just the round headlights) is to use TRANSPARENCY on your brush. Use a big, soft brush and adjust the transparency/flow on the brush right down (even to 10%). Just keep painting strokes (shift-click can create straight lines).
- You can keep changing between black and white by hitting "x".
Sorry if I've made it sound complicated. There would be lots of other ways, it's just I've used that recently and it worked really well. If you do want to give this method a go and get stuck, just ask. Good luck. |