ExpoDisc 77mm Professional Digital White Balance Filter - Portrait

The portrait-based ExpoDisc was designed to effectively deliver a custom white balance reading with your flash system of choice: with the disc in place, simply base your white balance customization upon an exposure using your flash system.

The ExpoDisc can effectively be used with step-up rings, so if you use lenses with varying filter size specifications you can buy one ExpoDisc for your largest lens and appropriate step-up rings for your smaller-diameter lenses.

Key Features:

• Hand-calibrated
• "Pop-on" design via three spring-loaded ball bearings
• 100% neutral diffusion
• Imitates both incident light or color meter
• Resulting 18% gray frame usable as white balance reference, exposure reference, or dust mapping reference
• Fine tune color at point of capture
• Replaces gray and white cards
• Spend more time shooting and less on workflow
• Convenient, fast and easy to use
• Effective in mixed and difficult lighting conditions
  

Here is how it works:

• Varying levels of colorcast typically occur in digital photography and require compensation as part of the process to create a photograph with good color fidelity; Until now, photographers have had to rely on gray/white cards to solve this problem
• ExpoDisc is an easy to use custom white balance solution that eliminates the inconvenience and inconsistencies of other methods; It is a neutral diffusion filter that gathers ambient light from 180 degrees and passively transmits 18% of it through to your camera's light meter; The resulting "gray frame" accurately represents the average colorcast of the light in which the photograph is taken
• From this gray frame, you then can set a custom white balance that results in accurate color in most lighting conditions; Your camera effectively compensates for and neutralizes the colorcast it sees through the ExpoDisc "gray frame"