Buy from Amazon.com : http://fave.co/1F0xEcW <br /><br />WhiBal G7 White Balance Studio Card<br /><br />Product Description : <br />Spectrally neutral - reflects all colors through the spectrum equally The G7 Reference Card has both a and b Lab channel values of less than 1 at D50 and are spectrally flat Its specd at less than - 05 <br />Maintains its spectral neutrality under all reasonable temperature and environmental conditions <br />Rugged - waterproof and scratchproof color goes all the way through not just a coating on top <br />Does not respond to UV light any differently than the visible spectrum <br />Each card is individually measured with a precision spectrophotometer to certify that it meets or exceeds stringent specifications
