Film has a distinct advantage over digital when it comes to grain: it's the only natural way to achieve it. Digital cameras are great at producing noise, but it's just not the same as grain. I'm in love with it — and I actually attempt to reproduce it in my digital photos when the occasion calls. If you need a refresher on when that might be, check out an article I wrote for Antoine called “Going With The Grain“.
The technique outlined below is intended to be a starting point for applying additional grain to a photo. I'll be using a section of the photo above to illustrate the method. It tends to work well with black & whites (especially those shot at a high ISO) and cross processed photos. You can follow along or download the Photoshop Action below. Either way, you'll probably have to tweak the results to get it looking just right.
Note that this action set contains all the previous Photoshop techniques I've covered in addition to the film grain technique. For help with using these techniques, check my Photoshop Tips archive.
1. CREATE AN EMPTY LAYER AND FILL IT
All of our noise will be non-destructive, so we need a new empty layer on top of the stack (Shift+Ctrl+Alt+N). Then we want to fill that layer with 50% gray (Shift+Backspace) — leave the blending mode set to Normal and the opacity at 100%. Now you should be looking at a gray screen. Wonderful.
2. INITIAL LAYER SETTINGS
I like to do these steps early in the game because it allows me to “see” how the grain is looking as I go through the rest of the steps, but you could just as easily do this at the very end. First, set the blending mode to “Overlay” — light tones get lighter, dark tones get darker — so 50% gray will cause nothing to happen (so you should see the original image again). When we add the grain, the dark spots will darken the shadows on image below while the light spots will lighten the highlights, while preserving the colors of the original image.
At this point, I also like to set my opacity to 65% and my fill to 70% — this will help soften up the effect once we apply the grain. If you use this at 100% opacities, you'll end up with very harsh grain. If you go down below 70%, you'll get a very light grain. These two settings are very important to achieving natural looking grain, and I'd suggest that you experiment with these values after the grain is applied.
3. BRING IN THE NOISE
Now it's time to start making things look different on our photo. We'll add some noise to the gray layer (Filter >> Noise >> Add Noise…), but don't freak out when it looks really bad at first. I like to add Monochromatic Gaussian noise with a value of 50% — this gives pretty good hard edges between the whites and the blacks, but there's still some transition between the two. What you should see in your preview is a really bad looking attempt at grain. It's going to be very blocky and un-grainlike. You MUST use the monochromatic option if you want grain instead of digital noise (and all the colors that go with it. You could also try using the Uniform Distribution — I find that it tends to create smaller grains, while Gaussian creates larger grains.
If you set your blend mode to Overlay already, you can see how the grain layer affects the image. You should be able to see blocks of lighter and darker spots throughout most of the image. The mid-tones and darker mid-tones tend to show the largest change, while extreme highlights will have almost no change in their appearance.
4. ADD BLUR TO SOFTEN
Now that we've added that terrible noise to the image, we'll back it off and try to get a natural look from it. The easiest way to do this with some amount of control is by using the Gaussian blur (Filter >> Blur >> Gaussian Blur…). I've found that a value of 1.3 pixels tends to work well with the Gaussian noise, but this is definitely another setting you can adjust to your own liking. As you adjust the value, you'll see the main image in Photoshop changing it's appearance — which is why I set the blending mode prior to this step.
Experiment with the blur value and different methods of applying blur. Photoshop offers several ways to add blur, and none of them are necessarily wrong. See what works best for your particular image and taste.
5. FINAL LAYER SETTINGS
If you're happy with the size and edge hardness of the grain, you can now go back to the layer opacity and fill values to find something that meshes well with your particular photo. You can also try a blending mode of “Soft Light” to give a softer… lighter… grain. You might also try some of the other blend modes, but you'll probably have to reduce the opacity WAY down to avoid any kind of bad distortions. Here's a before and after image for you (feed readers will have to visit the site to see the effect).
Like I said, this is just ONE way of creating grain in your images. There are a handful of methods out there, and they all give slightly different results. I use this method most often because it gives me control over many of the layer settings, and it's totally non-destructive so it can be turned off if I change my mind later.
Anybody else out there like to fake the grain? Leave me some links to photos of yours that have fake grain in them — I'd love to check them out!