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

[Gavjenks]

Erm?

The x-ray one looks indeed like x-ray, but they're obviously producing the x ray source themselves, which I can't do for a landscape, since it would be incredibly dangerous, expensive, and illegal.
the "Radio" one looks like just a regular visible photograph. Nor does the description of the file say anything about radio waves...
The microwave one is cool, but of the sky, probably using out-of-reach-of-amateurs satellites and such.
And the gamma ray one as far as I can tell is actually a visible light photograph of an oil slick on some asphalt, that the artist just thought looked abstractly like what he thought a gamma ray burst might be like.

And lol, yes, electricity in the 1930s indeed. So actually laptops would have been useful! Less so without a printer, but still useful. =P

 

[Gavjenks]

After thinking about this more, I realized that radio cameras are impossible as hobbyist projects, because diffraction prevents you from resolving anything at all with reasonable sized dishes, etc. Radio waves are meters in length.

So it would have to be short microwaves (1-2mm) to be practically sized (satellite TV type dishes) and still able to make any reasonable image. Microwave receivers are a lot harder to come by than FM receivers... The atmosphere is still like 50% transparent to them though between here and space, so you could still take images of things reasonably far away, although it would probably look like there was a thick smoggy haze, and very long exposures might be needed due to available light being absorbed by air all over the place.

Still a sliver of hope for an affordable non-visible/UV/IR camera, though! Also, there's always still Amolitor's afocal "walk around town with a GPS and a radio" idea.

 

[Derrel]

SNIP>>> there's always still Amolitor's afocal "walk around town with a GPS and a radio" idea.

Yes, that small consolation is the, "We'll always have Paris," of this thread.

 

[amolitor]

Yeah, I was gonna tell you that the reason for blobs was the long wavelengths, but I think you got there yourself. Also, lots of stuff is pretty much transparent to RF.

 

[Gavjenks]

Yeah the transparency thing was exactly why I thought it would look so cool. But oh well.

Is there some way to use linear polarizers to resolve better than the wavelength, like by taking a line of pixels perpendicular to the axis of the polarization, and then rotating the polarizer just a bit, and taking another line, etc.? Like, since you know which way the wave is, do you get an elliptically skinnier airy disk and any better resolution in the 90 degree to that?

 

[KenC]

There was someone on here shooting B&W using X-ray film which they got from a dentist who had gone over to digital X-ray images (as most have). I don't remember who it was. AFAIK it's also based on silver halide chemistry, so one could put it in a camera and use it for recording visible light. I suppose you could put it in some sort of light-tight frame, or even a camera with the mirror locked up and the lens cap on, and wait to see what you get from background radiation. I seem to recall that high-speed B&W film, like TMax 3200, actually was fast enough to be sensitive to background radiation in a location where it was higher than average. I don't know how long it might take to get an image with either film and whether you would get anything other than uniform noise. You might put some objects of greatly varying density in front of the camera and get somewhat more of an image (assuming you block the back of the camera with a radiation shield of some sort.

 

[Gavjenks]

I'll maybe try the high speed film idea, perhaps (although if it's that sensitive to backgroudn radiation, why isn't it all fogged from being shipped?). Maybe it would take a month or so? Also, it's hard to focus high energy rays. Just putting a blog of wood in front of the lens won't do much, because the light wont be focused into any sort of image. Just even fogging. A very dense material pinhole of some sort might work, though?. Hm.

As for "X ray film" I have used this extensively myself. It's not actually x ray sensitive film, it's just normal film. When they take an x ray they have a fluorescent screen that absorbs x rays and then discharges green or blue visible light which then actually exposes the film. Somehow they are able to focus it in the machines when they xray you. Possibly with diffraction?

If film weren't already quite sensitive to UV, you could do the same using a sheet of paper colored in with highlighters (UV pass filter --> film without backing like x ray film --> highlighter sheet; would fluoresce in visible spectrum and expose film even if only sensitive to visible)

 

[Gavjenks]

Aha! 1968ApJ...153L.101D Page L101

This looks like it might work for X-rays and even gamma rays.

Basically, you take a sheet of lead or whatever dense stuff, and perforate it with thousands of little pinholes, in a distinctive pattern. And put some low-density stuff in front that will block visible, etc. light but not the x-rays. Thus, you filter out the normal wavelengths, and get sharp images from diffraction, but still have a large aperture from the total combined light let through. You will get thousands of overlapping images, but they then explain how as long as you know what the pattern was, you can "decode" it on a computer back to one image, without losing data.

Nifty (and potentially very cheap) stuff! Will have to digest this more to see if the computer end of it is something I could understand well enough to code myself.



Or you can put the same plate in between the negative and a convergent lens in order to make a print of the "decoded" image purely in analog (basically reversing what you did originally, optically). Might be easier, especially with darkroom enlargers. (You lose resolution this way, though, since diffraction in visible is more limiting than diffraction in gamma, but I don't care about losing impossible detailed tiny amounts of resolution)