BrewZone

Digital Tilt-Shift Photos

Have you ever looked out of an airplane and thought the cars and people looked like toys? Have you ever wanted to build a scale model of anything? Me neither. But I have been on hikes and thought the town below was cute.
The true advantage of an old time view camera was the ability to correct for parallax by adjusting the relative angles of the lens and film plane. Buildings could be straightened, fields of flowers more easily kept in focus through movement of the lens board towards parallel with the subject. Doing the opposite created a minimized effect, with low depth of field, much like that experienced in macro photography. While the digital equivalents of perspective control and increasing depth of field (ie making things straight and sharp) are complex, making pictures blurry is a bit easier.
The basic steps are as follows:

1. Find a suitable shot. (Anything, even your living room will work if the perspective is looking downward and it has some contrast in the lighting.)
2. Do some preprocessing to emphasize the possibilities. (Eliminate foreground objects, highlight prominent features, increase contrast and saturation, over-sharpen a little)
3. Create a narrow band of focus using PhotoShop (or equivalents)
4. Create the final crop.

1. Taking the Shot

I decided during a recent hike to take some shots for a miniature effect. It was a hazy day, but there was enough contrast. I like street scenes because the cars and buildings look especially cute. Since I was shooting for an artificial look anyway, this rather bland shot was fine.

2. Preprocessing in PhotoShop

Using Adobe Raw, I tweaked the color balance, exposure and saturation.

In this case the tint was lowered (more blue) by 13, the saturation increased by 13, and the contrast increased by 25. Performing these steps after blurring may help achieve the best effect, but when shooting Raw format, it is better to adjust at this stage to get in the ballpark.
After you open the image in PhotoShop proper, sharpen heavily using an unsharp mask. (filter>sharpen> unsharp mask.) In this case, I used a radius of 5.1 pixels, at 70%. You can see the result in the next phase – creating a gradient for the blur.

3. Creating the Gradient in an Alpha Channel

Now we need to create a narrow band of focus to create the shift tilt miniature effect. In Photoshop, a slick way to accomplish this is by using a gradient to create a band of decreasing focus. Then the lens blur filter uses this gradient as a mask. First the gradient.

1. Set up the new channel. Open the channels window – under window in the menu bar, if it’s not visible. Create a new channel. The new channel (Alpha 1) should be selected. If not, click on it. Now click the eye to make RGB visible so your image shows through the channel.
2. Select the gradient tool on the Toolbox (keyboard shortcut g) (If it is not visible, right click the Paint Bucket tool and select Gradient Tool or type SHIFT+g)
3. Select a reflected gradient
4. Set your colors to default (black to your foreground color, and white to your background color) by clicking on the tools palette or using the keyboard shortcut (d).
5. Draw the gradient.
It took a couple of tries to get the gradient I wanted. Just keep dragging perpendicular to the gradient until you are satisfied. You want a narrow band of focus that highlights interesting details in the photo. Once you get the hang of it you can repeat the steps to generate additional channels, each with a different gradient, and then use each one for blurring.

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This article was written on Wednesday, October 3rd, 2007 and is filed under Making Creations. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.