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poco
20-Feb-2008, 07:45
http://www.washingtonpost.com/wp-dyn/content/article/2008/02/19/AR2008021902617_pf.html

Wouldn't you love to have bellows coated with this stuff?

Also, deep in the article it says:

""The more black the material the better," said Gerald Fraser, a physicist at the National Institute of Standards and Technology, the federal agency that specializes in fine measurements and industrial standards.

That agency offers scientists a chemical mix it calls "standard black," which for years has been the defining measure of blackness. Photographers and printers use it to calibrate their gray scales. Industrial radiologists use it to calibrate X-ray imaging systems that detect radiation or hidden defects in building materials."

Has anyone heard of or used this "chemical mix?"

John Schneider
20-Feb-2008, 08:56
It's an array of vertically-aligned carbon nanotubes, with a nanoscale roughness overlaid on the arrays. If the roughness is anything close to a fractal roughness, then yes it should be extremely black.

For those who are interested, here's the article info:
Experimental Observation of an Extremely Dark Material Made By a Low-Density Nanotube Array
Yang, Z.-P.; Ci, L.; Bur, J. A.; Lin, S.-Y.; Ajayan, P. M.
Nano Lett.; (Letter); 2008; 8(2); 446-451. DOI: 10.1021/nl072369t

ABSTRACT
An ideal black material absorbs light perfectly at all angles and over all wavelengths. Here, we show that low-density vertically aligned carbon nanotube arrays can be engineered to have an extremely low index of refraction, as predicted recently by theory [Garcia-Vidal, F. J.; Pitarke, J. M.; Pendry, J. B. Phys. Rev. Lett. 1997, 78, 4289-4292] and, combined with the nanoscale surface roughness of the arrays, can produce a near-perfect optical absorption material. An ultralow diffused reflectance of 1 10-7 measured from such arrays is an order-of-magnitude lower compared to commercial low-reflectance standard carbon. The corresponding integrated total reflectance of 0.045% from the nanotube arrays is three times lower than the lowest-ever reported values of optical reflectance from any material, making it the darkest man-made material ever.

If you had the time you could browse the ANSI standards for the black to which they refer; "standard black" doesn't bring up any search hits.

Ash
20-Feb-2008, 09:03
When I was about 10 I had thought about how you could have a cloak with mirrors and sensors to project the image from one side of an object to the other. I guess this is the real life version of what I imagined when I was sat in front of the tv...


Canon Head Office in the UK use huge 'light towers'. They are tubes placed outside that concentrate light through a channel and it reflects into other tubes lining the ceiling in the canteen, giving indoor sunlight. Anything is possible huh?

Michael Gordon
20-Feb-2008, 09:19
"There is something about this, that’s that’s so black, it’s like; “How much more black could this be?” and the answer is: “None, none... more black.”

Alan Davenport
20-Feb-2008, 13:00
Reminds me of the Jack London short story,The Shadow and the Flash (http://www.eastoftheweb.com/short-stories/UBooks/ShaFla.shtml).


"Colour is a sensation," he was saying. "It has no objective reality. Without light, we can see neither colours nor objects themselves. All objects are black in the dark, and in the dark it is impossible to see them. If no light strikes upon them, then no light is flung back from them to the eye, and so we have no vision-evidence of their being."

"But we see black objects in daylight," I objected.

"Very true," he went on warmly. "And that is because they are not perfectly black. Were they perfectly black, absolutely black, as it were, we could not see them - ay, not in the blaze of a thousand suns could we see them! And so I say, with the right pigments, properly compounded, an absolutely black paint could be produced which would render invisible whatever it was applied to."

Andrew_4548
20-Feb-2008, 13:19
and if it was that black that it couldn't be seen, you could avoid it by default by walking round the thing you can't see as you can see everything else around it so you know where not to go...

;)

Ralph Barker
20-Feb-2008, 14:37
I was working on an even blacker material in my lab. I had found a wayto embed bazillions of nano-sized black holes in the woven carbon fiber cloth.

Unfortunately, my lab has disappeared. :eek:

Ted Harris
20-Feb-2008, 15:05
Ralph,

I think your lab has been eaten by tribbles.

butterfly
21-Feb-2008, 06:29
This is a lovely conversation! Very entertaining. Never thought much about various levels of black before. Cheers! More please!

Ernest Purdum
21-Feb-2008, 19:00
I don't suppose it competes with nanotubes, but the ash from burning acetylene with no added oxygen sure is black.

The comment about roughness reminds me of the first time I ever thought of a rough surface being essential to fullest color (or lack thereof). In Sicily there is a common roadside weed which produces flowers of an amazing redness.

amilne
21-Feb-2008, 22:45
Wow. This stuff would bring theater to a whole new level. People would float.

Although I don't want to think about how many actor casualties there might be during blackouts.

John Schneider
22-Feb-2008, 09:28
I don't suppose it competes with nanotubes, but the ash from burning acetylene with no added oxygen sure is black.

The comment about roughness reminds me of the first time I ever thought of a rough surface being essential to fullest color (or lack thereof). In Sicily there is a common roadside weed which produces flowers of an amazing redness.

Actually, nanotube-relatives buckyballs and other fullerenes were first found in soot from a candle, so fuel-rich burning acetylene will be pretty darn black.

The more roughness, the greater the surface area, and thus the greater the color saturation. Likewise for deeper black; in the limit of a truly fractal roughness, the surface would have infinite surface area and thus reflect no light at all.

Joerg Krusche
22-Feb-2008, 11:52
Hi,

when I built for myself a long tube to mount some longer repro lenses .. to be used on a SL66 I found that the deepest black is delivered by some baffles in series that prevent any reflections from the wall surface .. this allowed to have a very deep black.. blacker possibly than some of commercial lens designs.

Thus .. if you take a closed box .. like when you buy shoes ...and make a hole into that .. say of 1 inch diameter .. then look at that hole and you will see the deepest black possible .. excuse my silly excursion !!

Joerg

Ole Tjugen
22-Feb-2008, 23:57
When I dismantled one of my very old lenses to clean the glass, I discovered that the inside of the barrel was blackened with soot. Not only soot, but a nasty sticky mess of soot and tallow - from a tallow candle burning in not much air.

In the end I cleaned it all out, and replaced the blackening with soot from a slightly "cleaner" modern candle. :)

G.A. Landrum
25-Feb-2008, 15:27
I'm surprised the article didn't refer to black body radiation. Color temperature, as measured on the Kelvin scale is linked to the radiation of the black body. This idea was taught to me in color class fifteen years ago.

Here's a link:

http://en.wikipedia.org/wiki/Black_body

G.A.

Hollis
27-Feb-2008, 00:19
My black goes to 11.

Michael Gordon
27-Feb-2008, 01:00
My black goes to 11.

Thank you, Hollis. I was afraid my post would go unnoticed. :p

John Kasaian
27-Feb-2008, 02:13
Has no one here ever been in a mine and the lights go out? Now that friends, is a deep black (in more ways than one!)

Hollis
1-Mar-2008, 16:41
Thank you, Hollis. I was afraid my post would go unnoticed. :p

Hey, I do what I can...

CG
2-Mar-2008, 15:37
.. if you take a closed box .. like when you buy shoes ...and make a hole into that .. say of 1 inch diameter .. then look at that hole and you will see the deepest black possible .. excuse my silly excursion ...Joerg

Not silly at all. Zeiss, if I recall, designed pretty much a fancy version of your shoe box to get a deep black for lab purposes. They mounted a shiny black inverted cone inside a glorified version of your shoe box hole and thus obtained a very dark spot.

C

Andrew Farkas
14-Mar-2008, 19:28
So this black is the darkest black yet, but can your eye tell the difference? Does that make photographers want it any less?

Joerg Krusche
15-Mar-2008, 05:50
Hi CG,

you are right .. I remember very well an experiment in which that shoe cardboard box with a hole to look at and some black velvet to compare with was shown .. the absolutely black velvet had a look of light-grey compared to that max obtainable black of that box .. there is no blacker black than that ... so if you take a repro lens and mount it on a long tube .. paint the interior black with some matte black .. and when looking through it .. it will appear light grey .. only when you introduce several round and thin baffles to eliminate practically all internal refelection you will have superb contrast on film .. and that can be obtained by any of us amateur designers if for example you mount a 600mm lens on a SL66 .. etc. Internal flare through reduction of contrast kills resolution of fine details .. but it can be controlled very easily by above simple means.

Best

Joerg

jetcode
15-Mar-2008, 13:32
New OLED technology is appearing in the display arena. Sony produced a 11" and 27" OLED TV's that feature 1,000,000 contrast ratio and and >100% NTSC color reproduction. This is because the OLED element can be turned off producing a black that has yet to be experienced in CRT or LCD technologies. In 5 years or less full size OLED monitors will be available. Sony is already working on these products.

http://www.engadget.com/2007/01/08/sonys-1-000-000-1-contrast-ratio-27-inch-oled-hdtv/