ExpoImaging ExpoDisc 77mm Digital White Balance Filter

ExpoDisc Professional Custom White Balance Filter

The ExpoDisc easily mounts to your camera's lens by pressure mount or can be held over smaller lenses.

Features:

• Quickly set white balance for photo and video
• Meter 18% Incident Exposure
• Individually hand calibrated, tested and certified in U.S.A.
• Durable aluminum filter mount
• Includes nylon storage pouch and black woven lanyard

ExpoDisc custom white balance (left) and Auto White Balance (right). Images copyright Zach and Jody Gray.

Why should I white balance with an ExpoDisc?

Because it saves time. The ExpoDisc White Balance Filter can be used to quickly set a custom white balance, virtually eliminating the need for RAW and JPEG color adjustments.

When used to set a custom white balance, the ExpoDisc consistently produces excellent color in natural, artificial, and studio lighting, and it even excels in difficult mixed lighting environments.

How does the ExpoDisc work?

Your camera’s internal light meter measures the color temperature of light passing through the ExpoDisc to make an “in-camera” color adjustment. This color adjustment is applied to all subsequent images taken using the custom white balance applied from the selected light reading.

Or, if you prefer shooting in RAW and batch processing later, simply capture a reference image through the ExpoDisc to use later with your image processing software.

How is the ExpoDisc different from other white balance tools?

The ExpoDisc is more accurate than other white balance tools because it is hand calibrated and certified for an 18% light transmission across the visible spectrum. We individually adjust each ExpoDisc using multiple custom filters to correct for any variation in base materials. This precision ensures that your camera applies the correct color adjustments when setting a custom white balance.

Using an ExpoDisc is also easier than using unwieldy exposure targets and gray cards, awkward tools that often require an extra set of hands to hold and position properly. To use an ExpoDisc, simply attach it to the end of your lens before setting a custom white balance or metering for exposure.

ExpoDisc representative Lab values: L*=49.40,a*=.-.06, b*.04, Z%=17.90 These representative Lab values were produced by measuring light passing through an ExpoDisc using a transmission spectrophotometer.

Why is it important to use a spectrally neutral white balance tool?

Only tools that reflect or transmit light evenly across the visible spectrum can be trusted to work properly in a variety of shooting environments.

As the inventors of the Custom White Balance Filter, we have always gone to great lengths to ensure the neutrality of every ExpoDisc. Any non-neutral white balance tool will introduce color casts to resulting images because the tool itself changes the color of light against which the camera applies the color correction.

How are ExpoDiscs constructed?

ExpoDiscs are made from multiple layers of custom formulated materials contained within a high grade anodized aluminum filter ring. Each ExpoDisc's filter combination is adjusted by hand to achieve its neutrality. To ensure that every ExpoDisc is neutral, we measure and calibrate each ExpoDisc at our California facility for 18% light transmission and neutrality across the visible spectrum (400nm to 700nm). This 18% light transmission is ideal for setting a custom white balance, as well as metering for incident exposures in ambient light.

Will the ExpoDisc work with my camera?

The ExpoDisc can be used with any digital camera with a custom white balance capability, including all digital SLRs and most point & shoot cameras. The ExpoDisc works with all major camera brands, including: Canon, Nikon, Sony, Pentax, Olympus, Samsung, Lumix, and Leica.

Auto White Balance in daylight (left) and ExpoDisc custom white balance (right). Images copyright Terry Livingtsone.

How do I use the ExpoDisc?

Getting great color with the ExpoDisc is easy. To set a custom white balance with the ExpoDisc, simply place the disc in front of your lens and follow your camera’s custom white balance procedure to capture an incident light reading through it. For most cameras, this procedure takes about 15 seconds. That’s it. If you’re shooting JPEG you’re done. And if you’re shooting RAW, simply download your images as shot and save yourself valuable time correcting color. No special software, and no post processing required.

Does the ExpoDisc work for video applications?

Yes, the ExpoDisc can be used to quickly white balance any digital video camera with a custom white balance function. White balancing your video camera with an ExpoDisc will save valuable time in the editing room adjusting for color casts and inconsistent color.

How does the ExpoDisc attach to my lens?

The ExpoDisc was designed to make white balancing your camera easy. To help accomplish this, the ExpoDisc quickly attaches to the lens using an innovative friction mount design. When gently pushed into a threaded lens or filter, three small spring loaded ball bearings located around the filter ring slide over the lens threads to hold the filter in position until removed.

Do I need to buy an ExpoDisc for all my lenses?

No, if you have multiple lenses you can purchase an ExpoDisc to fit your largest lens. When using smaller lenses, simply hold your larger ExpoDisc flush over the end of the smaller lens.

What ExpoDisc filter sizes are available?

ExpoDisc Professional Custom White Balance Filters are available in standard filter sizes, including 52mm, 58mm, 62mm, 67mm, 72mm, 77mm, 82mm, as well as 4x5.65 Video Format Filters.

Every ExpoDisc is individually hand calibrated, tested and certified in U.S.A.

Contents:

• ExpoDisc White Balance Filter - Neutral
• Nylon Filter Pouch
• Black woven lanyard
• Certification Card
• QuickStart Guide

What is a custom white balance?

Auto White Balance (left) and ExpoDisc custom white balance (right). Images copyright David Guy Maynard.

Even the best digital cameras struggle with consistently reproducing accurate color. Images shot with incorrect white balance may have unnatural looking red, yellow or blue tints that are time consuming and difficult to correct.

To help photographers cope with this problem, digital camera manufacturers have designed their cameras with multiple white balance functions, including Custom White Balance, Automatic White Balance (AWB), and factory Preset color temperature settings for Sun, Shade, Tungsten, Fluorescent, Flash, and Cloudy. When shooting, photographers must select one of the camera's fixed white balance settings to apply in-camera, or to apply later in post processing if using the RAW file format.

Unfortunately, Auto White Balance (AWB) often produces maddeningly inconsistent color results, and the color temperatures assigned to the camera's Preset white balance settings often do not reflect real world lighting conditions, causing a color-cast.

Using the Custom White Balance function remains the most reliable way to consistently reproduce accurate, balanced color in digital cameras. The custom white balance function eliminates the inconsistencies of AWB and the gross generality of factory Preset color temperatures because it allows the user to calibrate the camera to an exact color temperature at image capture. The custom white balance procedure requires a neutral reference like the ExpoDisc to measure the color of light accurately.