I ordered some samples of vantablack to use as a background against some silicon substrates I'm viewing under an A655sc and A40M. Curious if anyone has any thoughts if the darkest (technically the 2nd darkest now..) surface known to man will move the needle at all in increasing the clarity of the images grabbed by the TCs?
Tried (original Surrey nanosystems Vantablack) as a coating for FFC flags. No different to Halfords car matt black.
Both are somewhat better than 'black' anodising which can be quite variable and cause temperature readout errors by reflecting sensor temperatures back inwards.
note for non-UK - Halfords is a UK retail park car/bike DIY store
The guy who bought exclusive rights to vantablack is sort of a prick, so I'd recommend a different formulation if you're going to try others (also there's a blacker 2.0 version). I'm not sure any have been evaluated for LWIR performance, but at the very least you should not be getting any specular reflections of any kind.
I've considered Musou Black and Black 3.0 (though I've heard some earlier formulations, while not as dark, are more durable as coatings) as commercially available extremely black paints (and I think bother are considered less emissive for visible than the original vantablack), but I wonder how well each works in IR bands and how well they hold up to heat - likely important for a lot of thermal camera uses.
There is a video by Ben over at Applied Science that looks into the alternatives and how to make your own. It's a good watch to learn about the topic.
Although I doubt it would do anything useful for thermal imaging. The microstructures are smaller than wavelengths you see, so maybe you need a different formulation for LWIR wavelengths.
E: there was a thread a few years back looking at different paints and electrical tape options. Maybe you can find it via Google, I didn't.
IIRC he claims that black velvet is a reasonable alternative, whilst quite not as black it might be dark enough?
Since visible light is mostly reflection but infrared is mostly emission, it's two vastly different sources of optical noise.
And you don't necessarily need a 'dark' background. Just something really uniform. And not reflective. I don't know the exact setup that OP is using, but having something far away and mostly out of focus would work good enough I assume.
I would add that visually the Vantablack is truly mind bending. You just do not know what to make of it.
Bill
Like looking into a Black hole in Space maybe ?
Fraser
I would add that visually the Vantablack is truly mind bending. You just do not know what to make of it.
Bill
I second that. Have the coating on a high end SBIR blackbody for work. Even with 20+ years working with high end blackbodies like EOI, SBIR, and CI Systems, this coating just appears like a hole in space. Everybody who has come into the lab is amazed. It's not just visual but also striking in MW an LW too. Eventually I plan on measuring it's spectral emmisvity from 1-15um along with all our other BB's. Couple of them have competing Vantablack like coatings.
I would add that visually the Vantablack is truly mind bending. You just do not know what to make of it.
I assume you got a sample as a commercial request? I've not yet seen it yet myself and am intrigued! Annoying because I think it's made in town here
I assume you got a sample as a commercial request? I've not yet seen it yet myself and am intrigued! Annoying because I think it's made in town here
Yes it was commercial. Sent them a couple of shutters and came back with the blade part coated.
Bill
From what I tried, I got good emissivity results with... 3D printed ABS.
Note that coatings may have other important properties like thermal conductivity, low outgassing, useful temperature range, durability etc.
And it's difficult to achieve all of them: typically you want a thick coating to absorb, but that will degrade the thermal conductivity, a durable coating would use a binder that would outgas a lot, etc.
3D printed ABS is bad for many of these, but it is also so much less hassle.
I guess the good absorption comes from the macro and microscopic rougness. The later might depend on the specific ABS and temperature used though.
It would be a bad match if you're trying to build a blackbody simulator, but for baffling it's convenient.
And remember that good absorption in the visible doesn't give you any clue about the performance in LWIR, especially when comparing in the couple % reflectivity.