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Wednesday, April 22, 2009

The High Pass Filter

In the ongoing search for new techniques that will give your images a unique look and set them apart from the competition, the High Pass Filter can be another valuable tool for your business

This Article Features Photo Zoom

Pre-High Pass

Four decades as a photographer scroll easily through my mind as an ongoing loop of “new” techniques. In the late ’60s, posterizing was the hottest thing in the UCLA darkroom. Our student projects overflowed with starkly contrasting black-and-white images that took their lead from advertising and design photos worldwide. Cross-processing, infrared film, solarization and turbo filters—each technique had its time. As technology evolved, creativity nipped at manufacturers’ and engineers’ heels to grab the pieces that produced unique imagery. By 2009, these “cutting-edge” techniques, when they appear, are usually used as a way of creating “retro” images. New becomes old. And so it continues. Every iteration of what’s “new” has the potential to motivate serious photographers toward excellence, acclaim and an income based on creativity.

At present, Photoshop’s High Pass Filter is driving a wave. Photographers are living squarely in the vice of an unprecedented squeeze: a confluence of mass-market digital imagery and a financial meltdown. To simply survive the shrinking marketplace, photo professionals must go above and beyond the pack, must be creative and unique. In this context, High Pass Filtration is one way to gain an important artistic edge in a field of first-class contenders. The great news about learning this technique is that it’s not just an investment in style, but also an investment in your future. But I get ahead of myself....

High Pass Step 1	High Pass Step 2
The core step-by-step process for using the High Pass Filter is on the facing page. In the image on this page, a muted effect is created by inserting the following before Step 1.	In the pull-down menu, choose Image > Adjustments > Shadows/Highlights. Set Highlights to 0%. Set Shadows to about 60%.

Understanding The High Pass Filter
The process begins with shooting an image in the RAW file format. “RAW file” and “Camera Raw” are familiar terms to most photographers. Most understand it’s a larger file size. For High Pass purposes though, it’s helpful to understand in a bit more detail just what a RAW file is and why it’s preferable to a JPEG in High Pass work.

Although RAW files and JPEGs use similar technology to convert two-dimensional grayscale “maps” into color files, the differences are enormous in terms of how much image control remains available to the photographer instead of the manufacturer’s proprietary converter software (for example, Nikon’s NEF variants or Canon’s CR2). The difference among color converters not only differs from manufacturer to manufacturer, but also changes as technology evolves. In short, different converters, used in both RAW and JPEG files, are based on the manufacturer’s subjective interpretation of what looks “best” and can yield very different baseline results.