ProVideo Coalition.com: Camera Log by Adam Wilt | Founder | Pro Cameras, HDV Camera, HD Camera, Sony, Panasonic, JVC, RED, Video Camera Reviews

Last week, Art Adams, Tim Blackmore, Ted Allen, and I tested the Schneider 486 UV/IR cut filter on a RED ONE and on a Sony PMW-EX1. Tim wore his famous “doesn’t look anything like that in real life” “black” shirt, and we lit him with IR-rich incandescent sources.

Tim Blackmore in the hot seat at Videofax.

Tim and friends as seen by the Nikon D300.

But his shirt uses a fabric or dye that reacts strongly to IR and/or UV, reflecting a lot of energy back to the camera that’s outside of the human eye’s passband, but well within the limits of what a CCD or CMOS sensor can see. We have noticed that many cameras see that shirt as a reddish-brown, especially when ND filters are used (as they were in the outdoor shots in the three-camera comparison, to get all the lenses opened to T2.8). And while the RED actually does a better job than other cameras we’ve aimed at that shirt, even the RED’s rendition starts drifting when heavy ND filtration is used.

Our first surprise, upon setting up, was seeing that the RED saw Tim’s shirt as a shade of blue, neither neutral black nor reddish-purple. Furthermore, the 720p monitoring output seemed to accentuate the green-magenta axis excessively, more so than the onboard LCD did. Quick off-the-monitor shots from both the RED and a Varicam that Videofax’s Jim Rolin set up for us confirmed that (a) the RED saw Tim’s shirt as blue while the Varicam (like other video cameras) saw it as being reddish-purple, and (b) the RED’s monitor output exaggerated the green-magenta axis.

RED’s monitor output: exaggerated green & magenta; blue shirt.

Varicam’s rendition: less color exaggeration, red/purple/brown shirt.

Tim without any filtration, RED.

Tim with the 486 filter, RED.

In my frame grabs, I’ve color-corrected both shots to match on the grayscales; seen uncorrected, the 486 filter imparts a slight green/cyan cast (as you might expect, since its visible reflectance is red/orange).

With no NDs in place, the 486 had only a minimal impact on RED’s colors; it pulled a slight bit of purple from Tim’s shirt, but the shirt still reads as blue.