Gary Fong Lightsphere: size?

[erenales]

Wondering if anyone knows the right size (P1, P2, P3, P4) for a 580ex II flash. The site says P4 and P2. Confused between the two. Please help.

Thanks.

[scot079]

I have the C4 (cloud) for the 580 II so I guess it's the P4 you want

[erenales]

thanks...the P4 is what I will get.