Posted 18 December 2006 - 03:43 PM
Drew, right after I started MWB with Expodisc and was expecting the UWA lens, I ran a test. I had the Expodisc still in the Macro flip arm, the standard L&M (plastic CC Filter made by URPro) CC Flip Filter, and a glass URPro screw in CC Filter on the camera. With just the glass CC Filter, I could not white balance on anything below about 30', which was very strange to me, and that was both with and without the Expodisc. Normally my FX1 is very good down to about 50', and then the Expodisc is invaluable below that. However, with both CC Filters I could MWB from shallow to 80' (deepest part of dive) easily with the Expodisc, although it was a little too red due to two filters. Kirk at URPro assured me the two filters were identical composition, other than one being glass and one being plastic. I never followed up with Kirk after that, although I should have. So, should glass or plastic make any difference as far as functionality? I'm not sure, but I don't think so. So the other variable is the distance from the camera. The light entering the housing is tapering inward toward the camera. A filter further from the camera will have more surface area exposed, and closer to the camera would have less. I think it is probable that being so close to the camera, only a small portion of the filter is being used, therefore it would have less of the filtering effect by being right on the camera lens. I have not had time to do any more testing, but it would be great to have a good screw in CC Filter, so I can put my Macro Lens back in. Anyone having luck with a screw in CC Filter? Would appreciate any input. Most of my diving is in the 70-90' range, sometimes less, sometimes more.
My Expodisc MWB method: We normally have good sun and clear water here (South Florida, except near the sewage outflows) so I normally balance on the sun for medium to wide angle shots. Close up shots with the sun above or behind me, I will usually balance right on the subject. I don't care what anyone else thinks or says, I'll always use the Expodisc for white balancing, it is that good!!! The proof is on my 50" SXRD.
Light & Motion Bluefin HD, Sony FX1, L&M HID's
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