Get the IMAGE YOU WANT [Electronic resources] : Essential Photoshop Editing Techniques نسخه متنی

Add texture with simulated film grain

It's ironic how the moment digital camera technology overcomes a photographic problem, photographers start trying to find a way to re-create the effect using image-editing software. One of the benefits of using an image sensor instead of film is that the image is made up of pixels, not tiny grains of silver halide in the photographic emulsion, so the resulting images are smooth and free of graininess. But the grainy effect is a treasured element of photography, as proven by countless gritty black and white photos characterized by a raw and honest point of view. So, even though your digital images may be silky smooth, we can show you how to apply this creative effect and add to the atmosphere and depth of your photography, as we did in Figure A.

Figure A1.

Figure A2.

The photographic nature of grain

When a photographer shooting with film wants to get a "grainy" image, she uses fast ISO settings (ISO 800 and above) or uprates her film when shooting. Uprating involves shooting at a higher ISO speed than the film is designed for, which initially underexposes the film, and then pushes (overexposes) the negatives during the printing process. The effect is increased grain size and contrast, similar to the effect higher ISO settings have on digital cameras. Instead of film grain, the pixels become more evident in the form of noise. Just as digital noise degrades your image quality, grain can overwhelm an image (if not approached thoughtfully) whether you're adding it photographically or digitally.

NoteOf course, there are other ways to produce grain photographically, whether that be through enlargements or by using diluted print developer, but using fast ISOs and uprating offer the best parallels to the digital imaging process.

Adding grain with Photoshop

We can't tell you why Photoshop has three different grain filters, but we will tell you how each one works and how you can control them to get the grainy images you want. We've chosen to use grayscale images for our example, but film grain works just as well with full color images. Make sure your image is in RGB or Grayscale mode, as the filters we'll be using don't work in CMYK or Lab mode.

The Film Grain filter

It's funny that the one filter that should do exactly what we want it to is our least favorite option. Originally designed to help alleviate the effects of banding from a film scanner, the Film Grain filter adds an even amount of noise to the shadows and midtones of an image while applying a more obvious pattern to the highlights. To use this filter:

Open the image you want to modify in Photoshop.

Next, select Filter Artistic Film Grain to open the Film Grain dialog box shown in Figure B. Here you can control the size of your Grain, the sensitivity of the Highlight Area, and the overall Intensity of the effect. The Grain size ranges from 0 to 20, but anything over 5 tends to look very pixelated. You should also keep the Intensity setting low, but the Highlight setting can go either way depending on the tonal range of your image. To achieve the grain effect shown in the close up in Figure C on the next page, we set the Grain to 3, the Highlight to 4, and the Intensity to a modest setting of 1.

Figure B.

Figure C.

Save your image as a new file. Then, you can reopen the original file and apply the other filters using the same image each time.

The Film Grain filter can add a decent and very uniform grain across your image. However, it's difficult to control and the lack of a live preview makes it even harder to fine-tune your grain effect. If you were applying this filter to a group of images as a batch process, we could find some use for it, but overall the other two options give you more control with a better result.

The Texture Grain filter

The Texture Grain filter offers lots of choices for adding different styles of grain to your image. To access it:

Select Filter Texture Grain and the Grain dialog box opens, as shown in Figure D.

Figure D.

Click on the Grain Type dropdown menu to view your options, which are Regular, Soft, Sprinkles, Clumped, Contrasty, Enlarged, Stippled, Horizontal, Vertical, and Speckle. In our opinion, most of these options fall under the special effects category rather than a simple grain effect, but you can get a nice grain pattern using the Regular Grain Type.

In this filter, the Intensity option controls the strength of the effect and the size of the Grain, so lower numbers produce a more pleasing, subtle effect. The Contrast option adjusts the tonal range of your image on a scale of 0 to 100, with lower numbers decreasing the contrast and higher numbers creating more pronounced effects. If you set the Contrast to 50, there's no change in the image. The effect shown in Figure E was created. using the Regular Film Type with an Intensity value of 20 and a Contrast value of 55

Figure E.

Again, the dialog box lacked the live preview that makes adjustments so much easier, but the wide range of options makes the Grain filter a lot of fun to play with. If you're looking for a gritty look with lots of contrast, this filter is your best choice.

The Add Noise filter

With camera makers bending over backward to remove noise when an image is captured, it may seem ironic to use the Add Noise filter to subvert their efforts. However, the Add Noise filter is our choice for the best option for adding grain to an image. It includes a live preview necessary for careful adjustments, precise controls down to the hundredth of a percent, and the ability to set the distribution of the noise patterns. While the other two effects add noise to your image, they can't mimic the indiscriminate nature of real film grain. However, the Add Noise filter can.

To use the Noise filter, select Filter Noise Add Noise and the Add Noise dialog box opens, as shown in Figure F. The Amount slider is simply the intensity of the effect, but the interesting choice is whether to select Uniform or Gaussian Distribution. Uniform produces results in a completely random manner and is best used for full color images. For grayscale images like our sample, Gaussian is a much better choice as it uses a special curve to produce a wider range of light and dark pixels.

Figure F.

The Monochromatic option distributes noise evenly across your channels, which can be useful in color images, but not for grayscale.

To achieve the effect shown in Figure G, we selected an Amount value of 10.72% with Gaussian Distribution. The result is an image that actually looks like it was shot with high-speed film, not with a digital camera.

Figure G.

NoteOnce you apply any of the grain filters we've mentioned, consider adding a slight Gaussian Blur (Filter Blur Gaussian Blur) to smooth out any harsh edges produced and make the effect seem more natural.

Go with the grain

Adding grain to your digital images is a great way to add atmosphere and texture to your photography. We prefer using the Add Noise filter, but experiment with your own images and see which one works best for you. In any case, it's nice to have choices and Photoshop certainly delivers.