No birds, no bees, no proper time of day, November.
Paraphrased, it lacks a little something. But on the whole it’s that time of year that outdoor shoots feel as cold and drab as the weather, as the sky is encased in tupperware and everything looks a little ‘bleah’. Time to bring out the Warm Cards.
The light around us varies in its balance of colours that make it a ‘white light’. Daylight contains more blue than tungsten light. It’s measured in degrees Kelvin – which is like Celcius for pedants – and refers to the temperature you heat up a notional black substance for it to glow, so at 2,900 degrees Kelvin (3200K) it’s glowing like a domestic lightbulb, and at almost double that, a lot more blue and a lot less orange and you’ve got noon-day sun at 6500K. And so on.
Human eyes are pretty adaptable, but video cameras are not, and if set up for daylight, then used indoors, everything is too orange, and vice versa, the outdoors looks like a very cheap sci-fi frozen planet. Best avoided.
So there’s a white-set button on a camera. Point the camera at a card that is illuminated by your choice of light, and hey presto. Now, here’s the trick. If the card wasn’t actually white, what would happen? Yes, if the card were blue, the camera would increase the amount of green and red (yellow) to compensate, in the hope it would become white. Your picture would look a lot more yellowish – and hence ‘warmer’. Lots of emotional attachment to that sort of look – warm and golden spring to mind.
So behold the world of ‘Warm Cards’. They are perceived as a bit of an ‘Innovations Catalogue’ item by many, but those who use them swear by them. Supposedly manufactured to high tolerances (I’ll buy that), Warm Cards are incredibly expensive for what they appear to be, but I’ll say this: I’ve done many side by side comparisons between a Reference White card (not a Warm Card) and bits of paper, white walls, clouds, all sorts of ‘white’ things, and the Reference White is by far the best, accurate and ‘rich’ balance. Of course it would. That’s the point.
Here’s a video showing what Warm Cards do:
The biggest take-home should be the vast improvement of the White card over ATW and the preset 5700k daylight setting. For this alone, I’d recommend owning some sort of Reference White card.
But let’s consider the physics of what’s going on here. We’re ADDING things here. It’s not filtration, light is not being prevented from entering our system to create an effect. Neither are we boosting things in the edit suite, because boosting the ‘volume’ of colour raises the noise floor and potentially clips the higher signals.
Now, I originally owned a set of DSC Warm Cards, of which I only ever used the White, but used it on every shoot. This unfortunately was lost on a shoot a few weeks ago, so I had to replace it. DSC is a legend of test charts, but this time I went for the Vortex Warm Cards, which seem less Engineer Friendly but fit in kit bags, hang round your neck and include Cool and Minus Green cards.
Apparently, the blue hue of DSC cards is based on optimising the vectorscope setting for human skin (curiously, no matter what shade of skin you have, a vectorscope sees skin tone in one particular angle). I’m not sure how the Warm Cards are calibrated. I’m not so sure about the Warminess of the really warm Warm Cards, and whilst I like the 1/4 strength, it’s all a bit too much beyond that. However, I do like the Cool cards, but it will be the White card that gets used 99% of the time. Now, I think I may habitually use 1/8 Warm and 1/8 Cool, but purists, cynics and mates will chide me that nobody will see any difference but me and that this is nothing more than White Balance Homeopathy.
As I only want a couple of cards (White and perhaps the 1/4 Cool), I’ll give the thumbs up to the Vortex cards, but if I could get a DSC White card that was made with the same robustness and portability of the Vortex cards, I’d feel happier with it. But ask me in 12 months if I could tell the difference or wanted to swap with my old DSC White’n'Warm, I’m pretty sure the answer will be negative.