Is there any existing or possible method for radio, microwave, xray, etc photography?

[Gavjenks]

We all usually do visible light photography, and films and sensors can be made sensitive to infrared and ultraviolet fairly easily.

What about the other parts of the spectrum?
-Radio
-Microwave
-X-ray
-Gamma ray

I realize there are significant obstacles to all of these, but that doesn't mean it isn't possible to make everyday images using them.

Basically, what you need to detect a photon of light is a molecule that has some sort of transitional change it can make that very closely matches in energy required to the amount of energy that a photon of a given wavelength can provide. Transitions can be lots of things: ionizations, rotations, breaking or forming bonds between chemicals by providing enough initial energy, vibrations, changes in the energy levels of electrons, etc. Visible light is so easily detectable, because it has an amount of energy that corresponds conveniently to a wide variety of such possible transition modes. Low frequency light like radio waves is harder to detect, because it has very low energy and can't cause big enough changes to be very conveniently detectable. Gamma rays are hard to detect, because they have too MUCH energy to match with most convenient transitions. But inconvenient does not mean impossible...

Radio and microwaves:
These have low energy. They still have enough to excite loose electrons in a large enough piece of conductive material (like an antenna), and they have enough energy also to induce vibrations in some weak chemical bonds or relationships (like your microwave oven vibrating and thus heating up hydrogen bonds between water, or easily spinnable bonds in chains of fat).

Photographs could presumably be made by arrays of antennas (most likely sweeping across a very large format area as a scanning-type sensor, due to cost and space). Photographs could also possibly be made by measuring heating patterns of materials susceptible to vibration, and transducing that into electricity. Or, if you could find a piezoelectric material that vibrates from microwaves or radio, it is automatically transduced into electricity.

The antenna thing might not work in an array, because the fields from multiple antennae would interfere with one another. But if the interference could be "decoded" that might not be a problem. Or you could just scan for even longer with one antenna (imagine a dish and antenna panning across a 2-dimensional space of a couple of meters or so, each couple of milliseconds dumping its output as a "pixel")

X-rays and gamma rays:
These are too high energy to react directly in useful quantities with typical photographic compounds. However, you can use fluorescent intensifying screens. These use the process of fluorescence to absorb higher energy x rays, and output lower energy visible light. Basically, materials are chosen for a certain range of wavelengths such that one photon of light has just the right amount of energy to excite 2 electrons in the fluorescent material (or 2 excites 5 or whatever). Then each of those electrons calms down and emits light of only half (or 2/5 or whatever) the original energy, thus converting to visible light, which is easier to record. The visible light film is exposed in contact with the screen.

Normally, in a medical situation, you create a bunch of x rays, fire them at a patient, and then record the ones that get through. So you're creating your own (dangerous) light source. But can you do the same to photograph background radiation? It might take a few hours, and you might want to be at a high altitude to get a shorter exposure, but it should still work.

Or is there some reason this isn't possible?

Ionization is also a possible method that might be employed to record images from high energy photons like x ray and gamma rays. A screen of ionizable material at the desired wavelengths could record only sufficiently energetic light, and then some method could be used to record the subsequent radioactive decay from the newly made ions into electricity. Or the ions could chemically react with something to form a more stable image on analog film, to be developed later.

 

[480sparky]

Images of wavelengths outside the 'visible spectrum' are taken all the time.

Here's just one example.

 

[Gavjenks]

What's the point of all this? Well, "radio vision" of the typical outside world would probably look really cool. Radio towers and cell towers looking like bright street lamps, with diffraction patterns around landmarks, metal structures standing out from wooden ones, etc.

Weird, alien scenes or various types are the goal.

 

[Gavjenks]

Images of wavelengths outside the 'visible spectrum' are taken all the time.

Here's just one example.

To clarify, I'm talking about on a scale that might potentially be buildable or affordable by a hobbyist. Not multi million dollar space satellites or giant multi acre arrays of equipment.

(Some of the wavelengths shown there might BE from cheap equipment! But I'm having trouble finding much in the way of that from searching)

 

[Derrel]

Start with a big,big roll of tinfoil. Then, fashion a hat out of it. Then....

I dunno....that's all I got...

Looking fwd. to hearing more about this.

 

[Gavjenks]

Like for instance, if the scanning antenna idea works, you could make a radio camera for probably a couple hundred bucks:

1) Get a metal parabolic dish with an antenna at the focal point. Something pretty darn smooth: more so than a cheapo satellite TV dish. If necessary you might have to make one smooth enough, by using silver nitrate deposition or something.
2) Put a big tube of metal of diameter of the dish sticking out beyond the receiver (like a lens hood) to decrease non-focused light.
3) Remove the tuner from the system (you want to record all radio waves, not one specific frequency like usual, just like a camera records all visible light ideally, not one specific wavelength).
4) Hook up the amplified output to a computer that samples it in brief intervals to make "pixels."
5) Attach the dish (BUT NOT THE RECEIVER) to some 2-dimensional rack made of wood or whatever, that pans the whole thing slowly across a several foot space with little stepper motors, as the computer samples.
6) Focus by moving the antenna further or closer with regard to the dish (the distance a commercial receiver is at will generally be at infinity focus. Further away would focus closer). So it's helpful if the antenna distance is controllable. Aperture is going to be pretty wide here (a TV dish is usually about 500-700mm or so FL, and the dish is like 400mm across, so that's about f/1.4), so focusing will probably be important. Hyperfocal distance is probably best for most things.
7) Point it at something potentially interesting in radio and stationary, like a city scape, and turn it on.
8) Use a program on your computer to turn total electrical signal from the antenna at each "pixel" position to a lightness value from black to white, and arrange them spatially relative to where the dish was as it panned. This should appear as an interpretable image of the city scape in radio frequency.

Bonus: Very little spherical aberration, since it's pretty easy to find parabolic dishes. Also zero chromatic aberration, because mirror-based lenses don't suffer from that. Although you would have radio "donuts" in out of focus points of light, just like a visible catadioptric lens, since the receiver blocks the light in the middle.

 

[amolitor]

In RF you might find there's not that much interesting to see. Maybe, though! My guess is that you get blobs.

If you want interference patterns etc, you're going to have to get extremely frequency-specific, and even then I dunno. I don't think you're going to get any interference patterns around anything but really very large objects.

You could walk around with a crystal radio tuned to a local high power AM source, and map the signal strengths out. It wouldn't be directional, but who cares? There's only the one source anyways.

 

[GDHLEWIS]

The power consumption to build such devices would be through the roof and way beyond a hobbyist. Might be worth talking to some Astronomy folks as I know some do play around with mini radio towers but again that is a tall order photographing such things.

Good luck finding a solution would utterly love to see any results.

Ya lunatic

Keep it up!

 

[480sparky]

Whether or not the technology exists that's within the reach of an amateur, more to the point is whether there's a profitable market for the results. Stunning images of the Milky Way are a dime-a-dozen these days, and no one says, "Well, yeah. It's a great image, but I'd fork over even more money if you had an x-ray / microwave / gamma-ray / 1,000-meter version of it."

 

[Gavjenks]

Whether or not the technology exists that's within the reach of an amateur, more to the point is whether there's a profitable market for the results. Stunning images of the Milky Way are a dime-a-dozen these days, and no one says, "Well, yeah. It's a great image, but I'd fork over even more money if you had an x-ray / microwave / gamma-ray / 1,000-meter version of it."

I want to take radio images of landscapes, not the sky.

If they look like something other than blobs (which they should! Don't see why not), I think they could be really really cool looking.

Also, I'm mainly interested just for curiosity anyway, more so than profit.

The power consumption to build such devices would be through the roof and way beyond a hobbyist.

What makes you say that? Please note that I'm talking about available light photography. Which, for some uncommon frequencies or ones where you can only capture a small percentage of the light, it might require very very long exposures, but why high power?

Basically, I'm suggesting doing something like Amolitor's suggestion of walking around with a crystal radio, but in a more optically focused / direction way (although that would be fun too, amolitor!). Shouldn't necessarily require any more power than a AA battery or two (to amplify the signal enough to get it to the computer, is pretty much it).

If using something like an X-ray fluorescent screen, it wouldn't require any power at all (it's purely passively reactive). But background radiation might be low enough that you'd basically only end up imaging noise with an x-ray fluorescent screen. Also, I'm not sure how to focus x-rays, because I think they may be too high frequency to refract. Metal dishes may still work for reflective mirror lenses.

 

[480sparky]

I want to take radio images of landscapes, not the sky.

OK. Stunning images of the Grand Canyon / NYC skyline / Galapagos Island are a dime-a-dozen these days, and no one says, "Well, yeah. It's a great image, but I'd fork over even more money if you had an x-ray / microwave / gamma-ray / 1,000-meter version of it."

 

[Gavjenks]

I want to take radio images of landscapes, not the sky.

OK. Stunning images of the Grand Canyon / NYC skyline / Galapagos Island are a dime-a-dozen these days, and no one says, "Well, yeah. It's a great image, but I'd fork over even more money if you had an x-ray / microwave / gamma-ray / 1,000-meter version of it."

Well yeah... They don't say that, because they've never heard of a radio image of a landscape. Obviously, people in the 1930's didn't say "Man, I'd fork over a lot of money for a nice thin laptop," either. Does that mean laptops are useless?

They might also STILL never say they would pay more for a radio landscape after knowing what they look like, too. But then again, they might be cool enough to pay more for after all. Who knows? We have to try it first.

Also, the grand canyon would probably be pretty damn boring in radio. Cities are much more likely to be interesting, with multiple radio light sources within the scene, metal buildings and cars and things that absorb/reflect radio, lots of repetitive patterns in blocks for diffraction patterns, etc. It should look like something interesting, and it should look VASTLY different than a visible light photograph, because radio waves are very deeply penetrating through most common building materials, making many of the things opaque in a visible scene transparent or translucent in radio. The large wavelength should also make many more clearly visible diffraction patterns.

 

[480sparky]

Well yeah... They don't say that, because they've never heard of a radio image of a landscape. Obviously, people in the 1930's didn't say "Man, I'd fork over a lot of money for a nice thin laptop," either. Does that mean laptops are useless?......

In 1930, yeah, they'd pretty much be useless.

 

[Gavjenks]

You could walk around with a crystal radio tuned to a local high power AM source, and map the signal strengths out. It wouldn't be directional, but who cares? There's only the one source anyways.

By the way, although this would work to some extent, you souldn't ever get any crisp "images." It would be like walking around with a camera sensor without any lens attached. Over the course of taking measurements over many blocks or whatever, you might get something kind of interesting, that you might superimpose over a visible image or whatever, but it would be very gradual, blobby changes.

If you want a real "image" with a single perspective, you need to focus the light, just like with visible. A reflective metal dish is probably the best way to do that for radio waves.

In 1930, yeah, they'd pretty much be useless.

Yes, but you're focusing on the wrong part of the analogy... laptops would have been useless due to no electricity, etc.

But a radio photograph is a purely aesthetic object. It would have "usefulness" at any time in history when art was consumed for aesthetics alone (i.e., the last couple hundred years in the western world).

So the only thing holding people back from talking about it one way or the other is not ever having seen it before. It's not a matter of waiting for technology to come along. You don't need any special technology to appreciate a cool image...

I'm not really sure what you're getting at here, other than arguing for the sake of arguing. You really don't even want to see what it would look like? Honestly? If not, why not?

 

[table1349]

X Ray: http://www.alternativephotos.com/images/Main_body_left.jpg
Radio: http://upload.wikimedia.org/wikipedia/commons/b/b1/Lightning_hits_tree.jpg
Microwave: http://images.nationalgeographic.co...anck-microwave-universe-map_23165_600x450.jpg (the cosmic background)
Gamma Ray: http://images.fineartamerica.com/images-medium-large/gamma-ray-burst-samuel-sheats.jpg



Geek Helmet someone has been wearing: http://www.robotmutant.com/wp-content/uploads/2011/08/r2d2_helmet.jpg

FYI there was electricity in the 1930's.