B Camera Shoot Woes

[Opcode]

I was invited by a friend to shoot B camera at a place that does tattoo removal, which I gladly accepted because I wanted to get some camera practice and also compare footage. The primary camera was a JVC HD100U. I had barely had time to use my hvx prior because my mac has been in the shop since I received it, so I haven't really seen any footage except through the P2 viewer on my pc. And let me tell ya, I shot some real crap.

Format: 720/30PN

First of all, I didn't have a tripod, so I went hand helled and set it to auto focus. The angle I got wasn't that great and what happened was, evertime the doctors sleeve got in the shot partially ( I was zoomed tightly in), the autofocus would focus on it and ruin the shot. In hindsight, I should have set to manual focus and used push-auto whenever I needed to move around.

Second, having not tested the scene settings; I felt a bit experimental and used Barry's magic sauce settings which included Cinelike V and Cinematrix. This was a mistake because you shouldn't shoot with new settings without testing. The color gamma was way too intense, areas of least saturation remained so and areas that hit a saturation threshold had their colors intensified. The lighting condition inside is essentially a doctors office with what looked lilke near full spectrum flouro's. On one hand, the JVC footage was very clean, low contrast and very desaturated. It was a bit plain but very harmonius and I really liked the look. In contrast, my shot's were stylized and over saturated, especially viewed side by side. It looks like it can be corrected in FCP three way color correction in post quite readily as we slapped it on and desaturated the shots as a quick test.

Third, now here's the real shot killer. When I played back the footage, you can visibly see a periodic color shift through the shot in low frequency as it bounced between a warmer tone and a cooler tone. It was almost as if the auto white balance was operating sinusoidally. This really messed up the shots. I have no idea what it is but you can plainly see a periodic shift with a frequency of 2 seconds about.

Does anyone have an idea what would cause this. Is it possible that in Film Camera mode the shutter speed was enabled (180 deg) and that the flicker from the overhead fluoros would cause this coupling behavior. This is the only thing I can think of that would cause periodic artifacts. The camera was set on manual mode so the AWB shouldn't have been enabled unless I explicitly enabled it afterwards correct?) What I need to do is go back to the doctors office and shoot some tests. I really need to know what this is because it's a shot killer.

I have a few additional technical questions that will come in the following post because this is getting long.

[Barry_Green]

Always test before shooting whenever possible, so you can avoid surprises like this.

If you had the AWB assigned to one of the buttons in the SW MODE menu, then this could have happened.

More than likely, I bet you had "shutter off" set; this would default to 1/50th, and yes that could interact with 60hz fluorescent lights. If you had set it to syncro scan (180.0d) then that would have been an exposure time of 1/60 which should have worked fine with the fluorescents; I'm betting that you didn't specifically set it to syncro scan, so that means you had 1/50.

[Opcode]

Thanks Barry, I will investigate the shutter settings. The shutter confuses me, is the shutter on or off by default. If it defaults to on which I believe is true, I don't recall turning it off, the shutter then should have been enabled and set to the default of 180 degrees. I had previously removed AWB from the user buttons so that shouldn't be the cause.

When I go back to do a test, I'm going to try video mode and see what happens.

[Barry_Green]

"Shutter Off" is kind of a misnomer. What it really means is "custom shutter speeds off". Or, put more simply, it would be "shutter default."

The default shutter is... well... the default. You'd only have the 180.0d shutter if you specifically went in and selected it. So I'd bet that you were using the default shutter, which is (IINM) 1/50th in 30p mode, which would account for your pulsing fluorescents.

[Opcode]

I hope that's all it was, I nearly had a stroke when I saw the color shifting. It's good thing to know when shooting under fluorescents that they need to enable the shutter (not use default of 1/50) and sync to the lights.

I can't wait to get your book when it comes out. Thanks again.