Polaroid X-ray Machine
How to make radiographs on Polaroid film
But first, to see how cool this is, check out x-ray art:
Noah's x-ray art -- My favorite x-ray pictures
Initial stages that lead to my experiments:
1. Develop unhealthy, obsessive interest in x-rays at age 12. 2. Realize that you can buy anything on eBay.
These pictures were taken with an 80KV dental x-ray machine on Polaroid 600 color film. The neat discovery is not that you can buy x-ray machines off eBay. The neat discovery is that you can use Polaroid film to image x-rays!
Remember, an x-ray machine is not a toy. I especially would not recommend this hobby to anyone planning to have children or planning to not get cancer.
I have some sheets of phosphorescent plastic (plastic embedded with rare-earth minerals that glow green or blue when hit by x-rays). I used these sheets to detect the presence and the path of the x-rays while the machine was operating.
At first I tried to expose undeveloped Polaroid film to x-rays, but then I had to deal with the problem of developing the film in total darkness. Polaroid is fast, light sensitive film. I don't have a dark room. In the first picture (picture 0) you can see that the picture is almost totally white due to some exposure to light. Polaroid development is triggered when then film is ejected from the camera. While being ejected, the film is squeezed through two metal rollers. This causes a developer paste packet to burst open and flow between the layers of film. The film development stops automatically after a few minutes. I tried manually running the film through rollers, but I could never get the paste to cover as evenly as when the camera motor ejects the film. Plus, this has to be done in total darkness.
Then I discovered that the trick was to expose Polaroids to x-rays that were already in the process of developing. This, of course, seems backwards. Normally you expose your film before you start to develop it. The process works like this: You take a photo of nothing then after the picture pops out of the camera you have about 20 seconds during which the film is still sensitive to x-rays, but not to white light. At this point the picture of nothing is being developed. If left untouched it will turn black in about 60 seconds. Since the film is no longer sensitive to white light, so you can work in a well lit room. Before the film has developed you have a brief window of time in which the film is still sensitive to x-rays. This makes the job amazingly simple. Just set up your object to be x-ray photographed. Take a blank picture with the blind Polaroid camera. Place the film behind the object. Expose the object and film to x-rays. I found that 2 seconds of 80KV was enough to image bones in my foot.
Yes, I am aware of the dangers of x-rays. I realize that exposure to x-rays leads to leukemia and other cancers. For most of my photos I was well clear of the x-ray beam (15 feet away) cowering behind a steel plate. I did take a two pictures of my foot and one of my hand. Stupid? Perhaps. But it had to be done! The 2 second exposure was probably more than necessary as the photo is a bit overexposed. Frequent, long-term exposure to even small levels of x-rays may be hazardous. X-ray radiation is "ionizing" which means that it can create harmful free-radical chemicals in the body. These chemicals can mutate DNA which can result in cancerous cells. X-rays are photons. X-ray radiation is not a persistent radiation. That means that once the power is off the x-rays are gone. X-rays cannot cause other objects to become radioactive.
I don't recommend that anyone follow my lead. This isn't the dumbest thing I've ever done (by far), so please, if you are still tempted to write me to warn me that this might be dangerous, then you should know that you aren't the first to realize this. I wrote this about 6 years ago. I've probably heard it before. I don't own the machine anymore.
Search Google for, "dangers of x-rays".
Also interesting: X Rays and the Radioactive Workplace
ARRT study: Breast Cancer Incidence Higher For Early, Longtime R.T.s...
I have some other interesting x-ray links here:
- Noah's x-ray art -- My favorite x-ray pictures
- Noah's CT Scanning Notes -- Next I want to build a CAT scanner.
The First Radiographs I took
This is the first successful exposure. The entire Polaroid pack was exposed. Then I ejected the film. Not a good technique.
A shadow of a Crescent wrench. This was my first radiograph.
A vacuum gage used for testing vacuum lines in a car. I used this to figure out the expose for #3.
Same vacuum Gage with a 2 second exposure
The trigger spring of a paint ball gun
The CO2 chamber of a paint ball gun
A watch and a wind-up robot. The robot is on its back; feet to the left. You can see the shadow of the body and feet.
My left foot. It was hard to sit still. Dangerous? Perhaps. Stupid? Yes. But it had to be done! I couldn't stop myself. This will be the end of my self-experiments; at least until I receive my lead apron and x-ray dosimeter.
My left foot. This time I held still better. This view is from the bottom. My big toe is at the top of the picture. If you look carefully you can see the outline of the skin of the toes and the ball of the foot.