The Color Balance Lens (CBL) is a 2-sided disc with a gray side and a white side, to handle your needs of color balance and proper exposure alike. You use the white side for color balancing, and after the white balance is achieved you use the gray card for an accurate exposure reading.
Adjusting color balance with digital cameras varies, but in every case you hold the CBL in front of your camera and either make an evaluation or take a white-balance-reference picture. You should assure that the subject's dominant light source is also falling upon the CBL. Thanks to its complex, varied collection of prisms and lenses upon the 'white' side, the CBL grabs a large mixture of the light source and directs it into the camera during the white balance evaluation.
You are not reading light reflected off of subjects, and in this way the CBL is consistently more accurate just as incident light meters are more accurate than reflected light meters. You are not evaluating the white balance from a flat reflection of a gray/white card, which cannot gather as relevant a 'recipe' of reflected light from complex scenes. While white/gray cards or lens-attached white balance devices often yield fine results, it is in the most difficult lighting scenes where the CBL's design shines best.
To use the gray side for evaluating exposure, you simply use the CBL's gray side just as you do a gray card: use your camera's spot or partial metering mode if applicable, and place the CBL's gray side in your subject's lighting source.
Incident-Light Color Balancer
CBL Measures color balance of light incident to subjects, not reflected from subjects
Works with All Your Lenses & Digital Cameras/Camcorders
Buy once; CBL held at arm's length from camera (unlike filter-size-specific white balancing devices)
Eliminate Post-Processing Fuss
Spend your time taking pictures; CBL achieves perfect color balance in-camera at time of exposure, unlike devices which are used as reference tools later
You may return most new, unopened items within 30 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the 'Complete Orders' link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
We can ship to virtually any address in the world. Note that there are restrictions on some products, and some products cannot be shipped to international destinations.
When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.
Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.