Feb 19, 2008
By John Paul Caponigro

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Auto white balance on DSLRs is convenient. It gets you reasonable color fairly consistently. But … you can do better. Use a target.

The ExpoDisc Digital White Balance Filter is one of the most accurate targets available, suitable for use with any digital SLR or digital video camera with a white balance function.

The ExpoDisc is easier to use than any gray card, white card or calibration target. Simply place the ExpoDisc in front of your lens, aim at the light source, and expose.

The ExpoDisc uses your camera’s built-in custom white balance capability to turn the camera into an incident color-metering tool. This approach avoids the common problems and inconveniences associated with using gray cards, white cards and calibration targets: unwieldy size, unwanted reflectivity, improper angling and difficulty filling the frame.

Setting your camera’s custom white balance will generally eliminate the need for post capture color adjustments of JPEG files and can speed Raw file processing.

You don’t have to set custom white balance to use the ExpoDisc. You can use an exposure of the ExpoDisc as a target for individual or batch processing Raw files. This leaves your camera white balance at default settings (often Auto) and avoids the risk of forgetting to reset white balance in future lighting scenarios. It’s a totally optional solution that ensures you get ideal color.

But wait, there’s more!

The ExpoDisc can be used to correct vignetting (if you use their flats that can be used with any lens). While Raw converters provide limited shape control for vignetting correction, exposures made with the ExpoDisc precisely map vignetting associated with your individual lens and camera combination. You can use the exposure in Photoshop to precisely eliminate it.

But wait, there’s still more!

The ExpoDisc can be used to automate retouching sensor dust. Exposures made with the ExpoDisc provide a precise map of the position of dust on your sensor. Retouch the exposure of the ExpoDisc with Raw converters such as Adobe Camera Raw or Lightroom and you can batch process all other exposures from the same session with the click of a button. You only have to retouch a spot once and then never again. Make an exposure of the ExpoDisc everytime you change lenses and you’ll save hours of retouching.

The high quality, easy to use ExpoDisc delivers multiple benefits (white balance, vingetting correction, dust mapping) with one exposure. It’s almost foolish not to use it.

ExpoDisc filters are available with quick pressure release mounts in six standard sizes from 52mm to 82 mm. Also available are flats in 4x4 and 4x5.65. While they’re more expensive, I recommend the flats. They can be used with any lens. If you’re using multiple lenses, this means one ExpoDisc instead of many.

Prices range from $89.95 to $199.95.

See expoimaging.com for more information.

The latest addition to the PDN family, the PDN Gear Guide in print, has a total circulation of 30,000, and covers the latest and greatest in photographic equipment. Initially created in 2006 to be the official guide to PDN's annual flagship photography event, PDN PhotoPlus International Conference + Expo, the PDN Gear Guide is now also available online for gear news and updates 365 days a year.
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