love this!
> On 20. Nov 2019, at 07:53, Scott Dorsey <klu...@panix.com> wrote: > > Okay, old guy tells stories. > > > Back in the twenties and thirties, doctors would employ open fluoroscopes, > with an X-ray source behind the patient and a fluorescent screen in front > of them. X-rays passing through the patient would cause the screen to > illuminate and the doctor could see what was going on inside in realtime. > > Many of the old classic sequences that still show up in educational films > such as the man eating and man voicing different vowels and consonants, > were shot off the screen of an open fluoroscope. > > This approach has some problems.... namely it takes a lot of radiation to > get a nice bright image, and all of that radiation (not just the backscatter) > is pointed at the doctor. So although you can see open fluoroscopes in old > movies where W.C. Fields has swallowed his cigar, you will not see them in > use today. > > Because doctors needed to see movement and didn't want to irradiate themselves > constantly, a number of manufacturers made cinefluoroscope systems with a > Mitchell or Acme 35mm pin-registered camera movement, a very fast lens, > and a fluorescent screen all in one package. The high speed Leitz Noctilux > lenses were originally designed for these applications. > > These were in common use for heart imaging until maybe a decade ago, and > if you are looking for a film image you may be able to find cardiological > radiologists around with a film cineangography system. These systems all > provide full aperture 35mm images. So if you want 16mm you'd have to get > the lab to bump it down. > > All of these systems today have been replaced with high resolution video > systems. The nice thing about the video systems is that they result in > less radiation to the patient because the light sensor is faster than Tri-X. > These systems are small and convenient enough that some cardiologists will > have their own system rather than contracting it out to a radiologist. > The bad thing about them is that they tend to have more smear on motion > than the film systems because of the longer persistence phosphors. > > Now... if you don't need to deal with human beings, you can pour a whole > lot more radiation into the object. There are a bunch of fairly inexpensive > X-ray inspection systems for PC boards that give you realtime video with > decent resolution. Not very high energy radiation since they just need to > be looking at thin board traces for the most part. > > So... if I were looking to rent some time on a machine, I would ask a > cardiologist if they could recommend a local radiology guy, or I would > talk to PC board fab people, depending on whether I was looking at people > or objects. I have only done static x-rays, not moving ones, and there > aren't a lot of folks doing moving ones artistically today so it could be > really cool. > --scott > > > lens was originally designed > > _______________________________________________ > FrameWorks mailing list > FrameWorks@jonasmekasfilms.com > https://mailman-mail5.webfaction.com/listinfo/frameworks _______________________________________________ FrameWorks mailing list FrameWorks@jonasmekasfilms.com https://mailman-mail5.webfaction.com/listinfo/frameworks
