The 30 inch BalanceSmarter Photographers who shoot wider focal length lenses like the zooms shorter than 30mm, need a wider balancesmarter so we added the 30 inch model for them. It’s big enough to get a great white balance in studio or on location using long and very short lenses, yet still very portable too.
On-camera flash event and wedding shooters tell us this is the right size for shooting those short lenses because it easily fills any frame and makes fill flash color a breeze. The 30 inch size is the one located on all 12 of the student shooting stations at ShootSmarter University.

What is a BalanceSmarter? It’s a popup panel that comes in 3 sizes that you "take a picture of" to activate the custom white balance function (Also called PREset white balance in the Nikon world) of your digital camera. Each BalanceSmarter has a digital neutral white on one side and a digital neutral grey on the other. Can you see the center mark in the middle of each panel? That's for your autofocus to grab onto so you no longer have to fuss with turing your autofocus off and on again to make a custom white balance.