Setting the Custom WB with an Expo Disc and 40D

[porkchop2785]

I have a friend who has a 40D and he bought an Expo Disc that is 77mm, none of his lenses are a 77mm thread, would the expo disc still work correctly if you just hold the disc in place, also, I dont know exactly how to set the Custom WB in a 40D, any help would be greatly appreciated! Thanks

[esanchez]

yeap it will work

[andyz]

So long as the Expo disc is larger than the lens. In fact, Expo recommends buying the largest and holding it tightly against smaller lenses.

There are videos on the Expo Disc website on how to use it. Point it at the light source, snap a picture. Dial your camera to the Custom White Balance, select that shot, click Set and you're good until the light changes. The manual should detail the specific steps. I assume it is like my old Rebel and 30D and 5D.

[groovyone]

I also have the 77mm and use it with all my lenses. Just hold if flat up against the lens and you'll be good to go.

[porkchop2785]

great, thanks guys I appreciate it