Is there a way to get a green artificial turf field to appear blue by using lighting, and or filters including the possibility of lenses close to the eye like 3D glass? This field would be the same size as a North American hockey rink.
If you illuminate the field with blue lighting, it will appear blue.
If you give people blue glasses to wear, the field will appear blue. Few people seem to lnow (because few have read the book, and it’s not in any of the movies) but in The Wizard of Oz Emerald City isn’t really green. It just appears that way because the Wizard makes everyone wear green-tinted goggles. This would actually work.
If you’re asking if there’s some clever way of using non-blue glasses or non-blue lighting to make green turf appear to be blue, the answer is: Maybe. It depends upon the actual reflection spectrum of the turf, and what filters you can use. I’ve seen some odd color changes achieved.
Are you sure this would work? I’d wonder if peoples eyes might become desensitized to the green.
Wouldn’t it appear black? Green things look green because they reflect green light, and absorb everything else. If you shine a blue light on a green thing it will just absorb the blue light and reflect very little.
While this is true in theory, in the real world, green things usually reflect other colors to some extent, too. And common filters or bulb tinting aren’t generally highly monochromatic and allow through some amount of the entire spectrum, with the peak being the nominal color. So, yeah, it probably would look blue, if a fairly dark blue.
As QED has said, in practice most green things contain quite a bit of blue, so the odds are pretty good that the green grass will appear blue under blue illumination.
I was really annoyed at a guy who gave a lecture at a local Optical Society meeting when he asked what color a green object would be seen as under a blue light, and then said that, since the colors blue and green are different spectral compositions, the object would appear black. It’s true that if you looked at a blue laser light or a blue LED through a monochromatic green filter, it would not show up. But in the real world most green filters aren’t monochromatic, and neither is most blue light. Reflection and emission spectra in the Real World tend to be pretty broad, and if you get your blue light by putting a typical wratten or acetate or gel filter over a white light, and you’re looking at any garden-variety green turf, natural or artificial, you are going to have a considerable amount of overlap.
Try it. I’ve looked through colored filters for hours (watching 3-D movies, or looking at 3-D anaglyphic graphics, for instance). There’s some adaptation (pretty clear when you take the glasses off), but I still see things green through a green filter.
Found a photo which shows grass through a blue filter. Other pictures are nice too.
But still doesnt look all that blue to me.
Also, you can play around with the settings of a digital camera, as most new ones (I am sure about Canon only…) let you remap the colors. You could also change the color settings to get the shade that you want.
And the winner for best thread topic/username combo for 2008 goes to…
Hehe.
I hoped someone would notice!
As I said, it depends upon the spectra involved – the transmission spectrum of the blue filter and the reflection spectrum of the grass (and, of course, the emission spectrum of the light source). I can give you a random blue filter, especially if it’s light, and the grass will still look very green. A piece of blue plastic from a folder cover, for insytance, transmits a LOT of green. But a blue filter that transmits very little at the green end, like a relatively thick piece of cobalt glass, will make everything look blue. I GUARANTEE that a blue interference filter will, make everything blue. But it’ll also cut out so much light that you probably wouldn’t be able to see anything without a stronger source of illumination.
It’s definitely a wide pass filter used in that photo. The grass has RGB values around 9:34:13. Even the sky runs around 135:255:255.
The thing about using a filter in front of the eye is the blue tint would effect everything else, and our brains/eyes have an uncanny ability to kind of ignore (or get used to) that sort of overall cast to our vision. The best way to maximize a color change like that is to make the turf appear more blue relative to everything else. That means using gels and lighting to target only the turf itself.
>It’s true that if you looked at a blue laser light or a blue LED through a monochromatic green filter, it would not show up.
Though of course this is tough to do. I did look at a red laser diode through a green narrow bandpass interference filter from Oriel, and could see a little red light. This means the filter isn’t perfectly monochromatic and isn’t even a perfect bandpass filter, having enough transmission well outside the passband to let the laser be visible. CalMeacham is correct in this statement if we take “monochromatic” to be literally true, though it was fun to try with real world (if expensive) parts…
See my comments above. After hours ofwearing a green or red filter, everything still seems green or red to me. For short-term viewing – by which I mean on the order of hours – a blue filter should be fine.