alan2here Posted July 10, 2005 Posted July 10, 2005 Pinhole cameras work using a box with a pinhole in one end You can then see what is in front of the box by light cast onto the back of the box. Pinhole cameras dont have lenses My invention is a pinhole camera with these diffrances The box would be make of lead. The back of the inside of the box would contain a grid of sensors. The back of the outside of the box would hold a screen Each sensor's output is then conected to a pixel of the screen. The sensors could be for detecting input from a cirtain electromagnetic frequency or range. I know the sun produces all sorts of frequancys (including light) Some of those get though our atmosphere Some of those then bouce off the floor\ground\metal objects underground ect... and into my box via the pinhole in the front. For light my sensors would have to be light responsive diodes but that would be poinless as cameras that see in the visable light spectrum already exsist. As you are all interested in scince please respond (what frequency's would work best?, what sort of sensors would I need?, Is this just a stupid idea?).
d22k Posted July 10, 2005 Posted July 10, 2005 well nothing is a stupd idea, but why a pinhole camera? they are horribly ineficient, in that they let hardly any light in, you would be far better off with a lense. more importantly, what is this box supposed to do?
alan2here Posted July 10, 2005 Author Posted July 10, 2005 camras that see in infer-red (heat) cost a lot of money mainly because of expensive lense systems. Lense's for high frequency (xray\alpha\gamma) must be mounted to satalites where they are so big. Lenses for eny other frequencys tend to be impatical of non-egsistant. thats a standed pinhole camera, It would not work without the box. (the thing on the right is a tree it is photographing)
alan2here Posted July 11, 2005 Author Posted July 11, 2005 nevertheless glass lenses still only work for light unusual types of lenses would be needed for diffrent types of signals
insane_alien Posted July 11, 2005 Posted July 11, 2005 i've never seen an alpha lense(except from magnets and charged plates) before or a gamma lense. alpha radiation is a particle radiation not electromagnetic radiation. Gamma just goes through pretty much anything totally undisturbed. There are types of glass that allow infrared and UV through. below and above this you are betterusing a surface to mirror the radiation to a point (a parabolic dish). again the type of radiation to be reflected requires different materials.
alan2here Posted July 11, 2005 Author Posted July 11, 2005 i've never seen an alpha lense(except from magnets and charged plates) before or a gamma lense.. Gamma just goes through pretty much anything totally undisturbed... Thank you insane_alien, That was much apreciated Now back to my origanal questions: What frequency's would work best? What sort of sensors would I need? alpha radiation is a particle radiation not electromagnetic radiation. . That makes it a bit more complex as there are difrent types of signals The electromagnetic spectrum.
Sayonara Posted July 11, 2005 Posted July 11, 2005 It would help if you told us what you are trying to accomplish.
alan2here Posted July 11, 2005 Author Posted July 11, 2005 Looking though a screen in the back of the box and seing what is in front of the box but maby: Thin things or less dence things like cardbord become transparent Or maby so you can only see metal objects and everthing else is invisable. Or maby everything is black except white dots in the distance where radio transmiters are. Or somthing simerlar.
insane_alien Posted July 12, 2005 Posted July 12, 2005 do you mean having a screen that will absorb a photon(say an UV photon) and will then emit a visible wavelegnth photon? If that is the case it would be easier to use a sensor array to pick up the incoming photons that are invisible to the naked eye and then display it on a screen after some image processing. this is how it is actually done except special lenses are made to be transparant for the selected wavelegnth range. the sensors also have to be able to pick up the wavelegnth range as well. the pinhole idea would work but it would be very limited if it was only the one hole. If you had a disc that could rotate with many different sized holes on it it would allow you to display a greater number of wavelegnths. (this is because larger wavelegnths diffract more than shorter ones.) A smaller hole would be used for shorter wavelegnths. d22k is right though pinhole cameras are VERY inefficient when compared with lenses and may require large (>0.5 seconds) if you are taking a picture with one and for motion on the screen it will be very very dim unless you use sensors that have a low energy threshold and the signals can be amplified.
alan2here Posted July 12, 2005 Author Posted July 12, 2005 To use a sensor array to pick up the incoming photons that are invisible to the naked eye and then display it on a screen after some image processing.Yes, That is exatcly what I mean. the pinhole idea would work but it would be very limited if it was only the one hole. If you had a disc that could rotate with many different sized holes on it it would allow you to display a greater number of wavelegnths. (this is because larger wavelegnths diffract more than shorter ones.) A smaller hole would be used for shorter wavelegnths.Yes, What a great idea. d22k is right though pinhole cameras are VERY inefficient when compared with lenses and may require large (>0.5 seconds) if you are taking a picture with one and for motion on the screen it will be very very dim unless you use sensors that have a low energy threshold and the signals can be amplified.I'm open to implement this whith/whitout a lense at the moment, It would depend on the frequency's my sensors could pick up. I supose If they could pick up a range and where ajustable I may need a tuning knob.
mmalluck Posted July 12, 2005 Posted July 12, 2005 i've never seen an alpha lense(except from magnets and charged plates) before or a gamma lense. alpha radiation is a particle radiation not electromagnetic radiation. Gamma just goes through pretty much anything totally undisturbed. Dielectric lenses can be used to direct and focus all forms of electromagnetic radiation. Here's an example of microwave lenses being used with horn antennas: http://www.flann.com/Products_Home/Antennas/Lens_Horn/lens_horn.html The actual lens is the white disk filling the inside of the horn. Alpha and Beta particles are not EM radiation and therefore can not be forcused with a lens. The important part of the lens is the geometery and the dielectric constant of the material used. The constant determines how much the wave is defracted while passing through the material. A little math' date=' some materials data, and some skill with shaping plastics and you can make a lens for any wavelength. What frequency's would work best? If your box is used here on earth (which I'm 99.999999999% sure it is), your best bet is visable light and/or IR and UV. It's the greatest form of radiation present, with a wavelength thats easy to work with. Almost all x-ray and gamma ray radiation coming from the sun is attentiated by the atmosphere. Also, most people don't appreciate having x-ray or gamma-ray sources pointed at them. Cancer sucks. Microwaves and radiowaves would require a huge hole (more than a few wavelength across or you'll end up with the age-old single-slit experiment) for your pin-hole camera to work, as well as, a huge backplane to capture your signal with any decent resolution. We're talking about antenna arrays the size of football feilds. Not something you can really build. For instance frequency of 2.4 Ghz equates to a wave with a wavelength of 12cm. Your hole should probably be at least 36cm across. Take your pinhole camera and scale up the size of it, so that it's hole is 36 cm across and you'll see you have a huge honking camera. What sort of sensors would I need? As far a sensors go' date=' I'd get me some little IR detectors or photo transitors. Most light sensors will work over a range of frequencies with decreased sensitivity, but they'll work all the same. If you want something really cool, try getting your hands on the IR sensor (tube) out of a nightvision scopes. IR comes in one end, visible light comes out the other. You could just buy a ccd and build your own ccd based camera. or buy something cool like this: http://www-2.cs.cmu.edu/~cmucam/ camras that see in infer-red (heat) cost a lot of money mainly because of expensive lense systems. Not true. Inexpensive webcams can be turned into nightvision scopes by merely striping off the IR blocking coating on the lens. true, this type of IR is not heat based, but it still is pretty cool. http://www.mobile-review.com/forum2/showthread.php?t=29672 I seriously doubt you're going to be able to build anything that can see through walls, cardboard, or even sheets of paper. If it were that easy then everyone would have bought/built one.
alan2here Posted July 13, 2005 Author Posted July 13, 2005 Gama rays = Atmosphere in the way x - rays = Atmoshere in the way ultravilot light = I think would be rather lame visable light = Already have a didgital camera infer red = been done already Microwaves ,Radar, Tv, Radio = hole to big. :¬| Dang Oh well Also gama ray/x-ray sensors I found using google seem not to be small enough to make a resonable resolution grid of them whithout the overall size being big. I seriously doubt you're going to be able to build anything that can see through wallsYes, bulding it was going to be the next big hudle, Im usless at bulding enything. Thanks to everone who posted here.
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now