CX900/AX100 + DSC chart + Vectorscope

[Paul Anderegg]

My new $120 DSC Pocket Camette chat arrived today, so I threw my little HDR-CX900 on it to see how off it really is. I don't have any 3200k lighting with me at the moment, just LED, so I played around with the true white side of the chart in direct 5600k sunlight.

Well.......the colors are off, white balance as well. The camera insists that 1PM direct sunlight is 6100k. This is no surprise, as it thinks my 3200k incandescent lighting is 3700k. If you have ever used the push to white balance button, you may note that regardless of the kelvin it displays, it actually automatically adjusts the "OPTIONS" off-sets without displaying those values. In other words, you will get more accurate colors with 3200k push to white than 3200k using either the incandescent setting or manually setting 3200k.

So here is what I did. After confirming that the camera found the center of the vectorscope at 6100k using push to white, I set 6100k in the manual dial white balance, and adjusted the OPTION offsets until I got the vectorscope centered again. This gave me the cameras basic color correction matrix settings. They are A2/G1. I put A2/G1 into the options menu of every white balance setting except push to white, since it automatically adjusts these values. Brought the camera indoors and tested it out under house lighting. The new values carry over perfectly as far as I can tell. Home lighting whites around 2700k here, and the A2/G1 settings matched the auto white off the DSC card when I manually dialed in 2700k. I also visually checked the LCD on the camera as well as a 7" off camera LCD monitor, using the color side of the DSC chart, and they were accurate in hue and saturation, especially the blue panel.

These WB option offsets should carry over to the AX100 and X70 as well I would imagine. I have a Panasonic Varicam which was professionally aligned, and I use it to determine what kelvin my lighting actually is, which is why I know the Sony kelvin readout is wildly inaccurate. All my camera lights white at 3200 with the Varicam, and daylight whites at 5600k. If you are using these cameras along side higher end models, I would suggest not only using these offsets, but also adjusting your white balance kelvin 500k above what is displayed on the Sony readout. I will post some more on these issues in a few days, after I put the camera on a real high end vectorscope/waveform monitor at the station I work at. I am interested in how the Cinenmatone feature looks on the scope, and will be sure to post pictures of the vectorscope and waveform monitor screen with the Sony on the DSC chart under accurate 3200k studio lighting.

I should mention I have the new firmware version, and have always found the colors on this camera to be "off" quite a bit. I really feel good about the camera now. And yes, you need to put A2/G1 into AWB as well, as it was found to be just as off as the rest of the settings!

Paul

[Bruce Dempsey]

this is good stuff Paul I have an ax100 and want to implement your reccomendations but don't know how. If you have the time and inclanation could you describe how one might set those adkustment in camera please thank you

ah yes I see now pushing white balance brings up the menu <B-A:0 > G-M:0
really glad you are doing this and eagerly await your further discoveries
Bruce

[Paul Anderegg]

Did some additional incandescent light testing with my 100watt Lowel IDLight.

3200k preset requires A4 to center white balance on the vectorscope.

3700k manual kelvin with B1 centers on the vectorscope as well.

Push to white with the IDLight centered on the scope without problem.

These settings should provide perfect incandescent lighting (3200k) whiting. I am finding push to white handles those A-B G-M adjustments itself quite admirably without user intervention in all lighting conditions, including odd florescent and LED purple and green tinting. Keep in mind that just because your white balance is centered on a vectorscope, doesn't mean that your colors will be accurate. LED lighting will pull magenta and green vectors way off line, but still center on the scope.

Paul

[Paul Anderegg]

Some quick vectorscopes of various settings. Saturation was maxed out and vector was zoomed to compensate for the DCS charts native 50% saturation levels.

In order they are:

1: IDlight indoor preset A4.
2: IDlight 3700k B1.
3: Sunlight outdoor preset no adjustments
4: Sunlight outdoor preset A2 G1.
5: Sunlight push to white no adjustments.
6: IDlight stock JVC GY-HM790 from my work, ugly picture on those things.