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X-ray machine finally done!

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Wolfram

Thu Dec 16 2010, 10:00AM

Registered Member #33 Joined: Sat Feb 04 2006, 01:31PM
Location: Norway
Posts: 971

You are correct, your setup has the potential of much better pictures.

For the phone picture, it looks like you are running too low anode voltage to penetrate it properly, I'd guess you are somewhere in the 40-50kV area. You would get much better pictures if you ran it at something like 60-70kV. Also, make sure the camera is properly focused, it can be slightly off, and then all pictures will turn out blurry. I know I keep repeating this point, but but this is by far the most common problem, and it's not always as obvious as you may think. A good method to get the camera focused is to light up the screen with a bright flashlight, autofocus, and then lock the focus. Are you sure the fluorescent screen is alligned with the focal plane? Also, to get lower noise, I'd suggest turning down the ISO, opening up the aperture of the camera fully and turning up the exposure time. If your camera can save pictures as raw-files, I'd suggest doing that too, then you can exploit the full dynamic range of the CCD in your camera. Your x-ray screen will limit the resolution, but not to the extent you see here, so something else is not right.

Patrick

Thu Dec 16 2010, 10:08AM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

I defer to Anders M. s' judgement on this matter.

Proud Mary

Thu Dec 16 2010, 10:15AM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Anders M. wrote ...

For the phone picture, it looks like you are running too low anode voltage to penetrate it properly, I'd guess you are somewhere in the 40-50kV area. You would get much better pictures if you ran it at something like 60-70kV.

Strange days have found us...

IntraWinding

Thu Dec 16 2010, 11:21AM

Registered Member #2261 Joined: Mon Aug 03 2009, 01:19AM
Location: London, UK
Posts: 581

The pictures already look good to me, but perhaps you can get a high resolution manually focussed web cam or other digital camera?

Do you have a photo of the bare tube?

Freitsu

Thu Dec 16 2010, 11:40AM

Registered Member #3147 Joined: Sun Aug 29 2010, 10:53AM
Location: Finland
Posts: 56

I raised the voltage somewhat and got a little bit better contrast on that phone picture (but alot more interference from x-rays ofcourse). My digicam isn't the most modern out there so it doesn't let me play with all the settings. I'm quite happy with the results for now. I have the reflecting mirror slighly off by 5 or more degrees, that might cause my pictures to look a little bit wierd aswell.

IntraWinding, I updated OP with a pic of the tube.

Adam Munich

Thu Dec 16 2010, 11:40AM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

Have you put lead around the tube with an aperture hole? That will cut down on stray x-rays and improve the image.

Edit Oh IC you did. Try a smaller hole though.

Wolfram

Thu Dec 16 2010, 02:37PM

Registered Member #33 Joined: Sat Feb 04 2006, 01:31PM
Location: Norway
Posts: 971

Proud Mary wrote ...

Strange days have found us...

Strange days has tracked us down...

I guess most, if not all of the characteristic L lines from tungsten get lost in the glass envelope. The K line peaks do not, though, and they contribute significantly to the x-ray beam when the anode voltage is over 70kV.

Freitsu, the results you have gotten so far are good, but the reason I keep bugging you about improving the image quality is that I know this method can yield very good results. Here

are a few sample images taken with the same method. Using a camera that gives you complete control over exposure factors is important, and SLR lenses tend to have so much glass that they shield a significant amount of the radiation.

radhoo

Thu Dec 16 2010, 04:28PM

Registered Member #1938 Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 701

Anders M. wrote ...

know this method can yield very good results. Here

are a few sample images taken with the same method. Using a camera that gives you complete control over exposure factors is important, and

Are these two pics recorded on photo-film or directly on CCD camera?

Wolfram

Thu Dec 16 2010, 07:07PM

Registered Member #33 Joined: Sat Feb 04 2006, 01:31PM
Location: Norway
Posts: 971

Directly on a CCD camera, by photographing a screen from an intensifying cassette. The pictures have had the contrast increased, in the spark plug picture, I used some noise reduction, and in the Stylophone picture, I inverted it so that it would look like typical x-ray film.

radhoo

Thu Dec 16 2010, 08:04PM

Registered Member #1938 Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 701

Anders M. wrote ...

Directly on a CCD camera, by photographing a screen from an intensifying cassette. The pictures have had the contrast increased, in the spark plug picture, I used some noise reduction, and in the Stylophone picture, I inverted it so that it would look like typical x-ray film.

I would be interested in seeing the original pictures, without any digital processing, by any chance do you still have them?

The quality is exceptional, very encouraging to see such results. What kind of X-ray source have you used? I assume some kind of lead enclosure with a tiny window was also used?

Some other details like distances between objects would be useful.

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