Are X-Rays macros?

[Joseph S. Wisniewski]

Day 9 of the broken wrist saga, can't shoot, can barely type, can't play a flute, sleep at least 12 hours a day...

So, what have I got? Lots and of time, and drugs...

Which brings up the obvious thought: since X-Rays are essentially shadows, shot by consummated "light", they are always at 1:1. Does this make them macros?

[mgoodm3]

X-rays often have magnification beyond 1:1. A typical film will have a magnification of anywhere from 10-30% because the x-ray source is a point source and the film is not immediately adjacent to the structures that are being imaged. Depends upon what parts you are shooting. There are some imastanceas where you intentionally move the film away from the part to add extra magnification.

Actually, traditional x-rays are exposed by light and not the direct effect of the x-ray. The xrays strike a rare earth "screen" and the screen emits a bunch of visible light photons that then expose the adjacent x-ray. That provides an amplification of the signal and allows less x-rays to be used.

[mgoodm3]

my icon is an x-ray of an buffalo nickel.

[rjlittlefield]

Does this make them macros?

Well, the fellow who coined the term "photo-macrograph" did so with these words:

Photo-macrography. Worcester defined Macroscopic or Macroscopical as "noting an object which, although comparatively minute, is visible to the naked eye or to the eye assisted by a pocket lens," -- usually an inch or more in focus and magnifying less than ten diameters. A delineation or picture of an object thus enlarged would be a macrograph, and if produced by the aid of photography, why should it not be termed a photo-macrograph? At all events I have chosen to coin that word and to define it as a slightly enlarged picture or delineation of a macroscopical object produced by means of a lens and sensitized photographic plate.

So I guess the question is whether you'd consider a wrist to be "comparatively minute".

Personally I would not, so I'd be inclined to call an ordinary non-enlarged X-ray a "close-up".

On the other hand, if you were to take a high resolution X-ray and blow it up 5-10X so that the smallest bone chips became easily visible, then you'd have a "macro".

--Rik

Reference: The quote is from pages 86-87 of "THE A B C OF PHOTO-MICROGRAPHY / A Practical Handbook for Beginners", W. H. Walmsley, 1902, currently available online at Google Books as http://books.google.com/books?vid=LCCN0 ... 9KZKfdMTIC, page 104 of the pdf file.

[Harold Gough]

Actually, traditional x-rays are exposed by light and not the direct effect of the x-ray. The xrays strike a rare earth "screen" and the screen emits a bunch of visible light photons that then expose the adjacent x-ray. That provides an amplification of the signal and allows less x-rays to be used.

This might explain why airport security X-Rays are not such a problem to photographic film as we might expect.

Harold

[mgoodm3]

Airport x-rays are a little different but amplify the signal using fluorescent screens and a photocathode so you get a reasonable video output.

[Jbailey]

Joe:

Of course x-ray images can be macro if done close enough. Before my retirement I worked in industrial R&D and took several closeup radiographs of electronic componants and circuits for quality control and study. Unfortunatly I no longer have access to them. Some of the photos included close-ups of transistors showing the internal details, including the tiny wires.

Most photos were taken on Polaroid 4X5 Sheets using a friendly Dentist's machine. We couldn't justify purchasing an industrial setup--including a properly shielded room for the few shots we need to make.

Incidently, the dentist was intrigued by our results and methods.

Jim

[Graham Stabler]

Here you go. A frame from a CT scan of a honeybee thorax. It only shows the rear half but you can make out the longitudinal muscles going diagonally upwards left to right and the hump back scutellum at the top left. You can also make out the wings which drooped to a bit of an odd angle during the scan. This was done on a Skyscan micro CT scanner at Bristol University. Resolution is about 2um in this scan.

If you want to build your own you just need a Hamamatsu focussed x-ray source, a scintilator with tapered fibre optic intensifier feeding to a 12 mega-pixel camera. Oh and a stepper motor

[Mike B in OKlahoma]

This might explain why airport security X-Rays are not such a problem to photographic film as we might expect.

Not to beat a dead horse, but if you put your film in your CHECKED baggage, they may be exposed to more powerful X-rays that may damage your images. We wear dosimetry equipment to monitor radiation exposure, and one of my employees took his dosimeter with him to a training course. He put it in checked baggage, and when we processed his badge later, it showed a significant (from the point of regulations, though not enough to threaten health in the near term) radiation exposure above what he would normally receive. We were having a snit over where he could have picked up the unexpected exposure until I questioned him carefully about this.

But Harold's comment is absolutely correct about the machines used to scan carry-on lugagge.

[Mike B in OKlahoma]

If you want to build your own you just need a Hamamatsu focussed x-ray source, a scintilator with tapered fibre optic intensifier feeding to a 12 mega-pixel camera. Oh and a stepper motor
]

This can actually be done surprisingly easily. There are some photographers who market GORGEOUS X-ray shots of flower internal components using a low power x-ray machine (most industrial and many medical x-ray machines would simply overexpose the shot, having too much power to capture these details).

http://www.fineartcompany.co.uk/s-57~x-ray_photography

http://www.judithkmcmillan.com/

Note that if you do this, it is "X-ray industrial radiography", which is subject to government regulation in most of the developed world, including requiring a permit. (I'm one of the guys who issue and inspect those permits, so am kind of attuned to this issue!).

[Graham Stabler]

This can actually be done surprisingly easily.

That stuff it pretty low resolution in comparison.

Graham.

[Harold Gough]

[quote="Mike B in OKlahoma
But Harold's comment is absolutely correct about the machines used to scan carry-on lugagge.[/quote]

That's why I cram my 60 or so cassettes, minus boxes and canisters, into my shoulder camera bags (one carried by the wife - she has her uses).

Harold

[Cyclops]

my icon is an x-ray of an buffalo nickel.

Ah,I was wondering what it was!

[Joseph S. Wisniewski]

Right now, I'd be more concerned with getting my own body through airport security, with my wrist full of metal pins.

Dr. appointment went well today, new, more comfortable cast. Pins come out in two more weeks. I got dizzy and had to lie down when they cut off the old cast and I saw those pins sticking out of my wrist.

On the bright side, the x-rays they shot today include two at angles that appear just right to make a good stereo pair. I can't wait to get a copy of those files. Most of the files from the previous x-rays on this "adventure" have had too much parallax.

This can actually be done surprisingly easily. There are some photographers who market GORGEOUS X-ray shots of flower internal components

Yup. I know one of the greats. Albert Richards (x-ray Al) at the University of Michigan has been doing this literally since before I was born.

Albert Richards

He's good, his large enlargements are stunning. He's had floral radiographs on the cover of Smithsonian.

Another radiographer I know does the most lovely hand colored x-rays of flowers and seashells (I think shooting at least one nautilus is "mandatory" among the fine-art x-ray crowd).

Now, if I can pursued my wife to let me seduce one of the cuter x-ray techs at St. Mary's hospital, so I can get access to the equipment...

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[Harold Gough]

I got dizzy and had to lie down when they cut off the old cast and I saw those pins sticking out of my wrist.

Thanks for the reminder. When, about three years ago, my wife had a minor operation to have a bone in her foot reshaped, I took pictures of the shiny pins protruding. That also qualifies as close-up/ macro! When I get my scanner running...

Harold