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Tuesday, May 25, 2010

How To Go Wide

Pointers For Panoramas • The Dark Side Of Wildlife Photography • Presentation Preparation • Filter Essentials

Most mid-level digital projectors are capable of a resolution of 1024x768, although some new higher-end projectors resolve at 1400x1050 (Canon REALiS SX6 or SX80) to 1920x1200 (full high definition in the Canon REALiS WUX10, about $8,000). Typical LCD laptop computer displays resolve at 1440x900 (MacBook Pro) to 1920x1200 (iMac). Ideally, you’ll size your images to match the projector’s capability, but consider the possibility that you’ll give the program again in the future on a higher-resolution machine.

Because I always want the sharpest image possible for my programs, I size my images at a horizontal width of 2000 dpi, and a vertical image at 1000 dpi wide at a screen resolution of 72 dpi. This exceeds the capability of my current projector (1400x1050), but not the one I hope to be using in the near future!

Outputting the images in JPEG format and compressed to approximately 8 on the Photoshop scale will keep the overall program size small so that the processing power of your laptop isn’t overwhelmed. Even at the projector’s best possible resolution, enlarged images will look softer, so you should sharpen them slightly after they’re sized and just before they’re saved as a JPEG for use in the presentation program.

Filter Essentials
Q What filters do you deem “must-haves” for digital photography?
W. Dalton
Via the Internet

A The most important filter for my own work is the neutral-density filter, which enables a longer exposure in sunlight for rendering milky, flowing water or to lengthen exposure in any light conditions for creative effect. Rather than carry several different filters of different densities, I use the Singh-Ray Vari-ND, which covers a full range, from 3 stops to 8 stops. A gradient ND filter (which darkens only a portion of the frame, such as the sky) is useful in high-contrast situations. While I normally use HDR techniques to control contrast, the gradient filter works better when the subject isn’t stationary, such as when following a herd of animals moving before a bright sky.

Polarizing filters still have a place when the sky needs to be darkened or reflections need to be removed from shiny surfaces. Reflections mask color and detail, and it’s better to accomplish their removal before you get to Photoshop. The blue/gold polarizer is a filter for effect, to cool or warm a scene in a very distinctive manner. It’s not a filter I use often, but it can save the day, and I carry one with me.

Finally, some photographers might use an infrared (IR) filter to achieve the effect of infrared capture without converting their cameras to “pure” infrared. The problem with IR filters is that they lengthen exposures significantly, and they don’t work with every camera due to variations in the effectiveness of the IR “cut-off” filter inside the body. I prefer to work with a DSLR converted to maximize IR capture.

For information about upcoming seminars and digital-imaging workshops, visit www.georgelepp.com. If you have any tips or questions, address them to: OUTDOOR PHOTOGRAPHER, Dept. TT, George Lepp, 12121 Wilshire Blvd., Suite 1200, Los Angeles, CA 90025-1176 or online at www.georgelepp.com.


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