I'm sure most know this, but the x-ray film machines in question emit x-rays that travel through the subject and hit a phosphorescent screen. Some machines have a blue screen whereas others have a green one. The screen lights up and exposes the x-ray film. As a result, we have film tailored for a green screen, and film for a blue screen.
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
Yes, and it's all on a blue plastic base, as you state.Originally Posted by Peter De Smidt
I have read the entire X-Ray Saga, but don't recall anyone saying what Randy just wrote.
Tin Can
Not sure why the films have a blue base maybe not to make bones too white compared to flesh?
Blue and green refer to spectral response of the emulsion not the base.
Most X-ray equipment for diagnostic use assumes the film goes in a film cassette in a darkroom. The film cassette has two phosphorescent layers which interact with the X-rays, absorbing their energy and re-emitting the energy as visible light of a particular color (blue or green it seems). A large enough dose of XRays will expose the film themselves but the phosphor screens allow exposure of the film at a much lower X-ray dose since much of the X-ray dose goes through you AND the film. Lower X-ray dosage is generally a good idea.
A sticky: well I wrote something up but it was too long for in system. I think I sent it to one of the moderators and maybe the site founder. ??a year ago?? Nothing happened. If it got eaten by the internet I could resend. But the remarks yesterday encapsulate most of what I think you'd need to know to start. Someone ?Andrew O'Neill? Posted a reciprocity failure chart too.
Ok; I WORKED AS A nuclear medicine technologist back when film was the only way to get an image. Now of course, most medical imaging is digital and read off a computer screen. I worked with and around plenty of Radiologists as they read the films. The reading rooms had large light boxes on the walls. In a major facility they might cover the walls on three sides. The radiologists kept the ambient light low so most light in the room came from the light box through the film, and you look right at it . . .intently.
The blue base helped keep glare down and was easier on the eyes after several hours. That is why it is bluish.
Imaging for Nuclear Medicine was a bit different. The film recorded an the bright spots from a 4-5 inch CRT that built up ofer several minutes to form a useful image. Phosphor screens were not used.
I found that the film would load right into a 8x10 film holder and work I my Kodak 2D. The single emulsion sheets were developed in the same chemistry as the X-Ray film in a Kodal x-Omat roller transport processor—ninty seconds dry-to-dry! This chemistry was also compatable with rolls of 220 Tri-X.
After some testing it seemed that it was pretty panchromatic and rating the film at ~200 ISO worked. I made some nice images that way.
This film is still available new as "Ektascan" and can be had in either clear or blue base—but only in 8x10 I think. The sheets have rounded corners with a single V notch.
Drew Bedo
www.quietlightphoto.com
http://www.artsyhome.com/author/drew-bedo
There are only three types of mounting flanges; too big, too small and wrong thread!
I don't think anybody here knows of a clear base Ektascan!
We need to find it!
Tin Can
Well I used it as late as 2003 before I had to retire. So, OK, that is 13 years ago and time is cruel.
Drew Bedo
www.quietlightphoto.com
http://www.artsyhome.com/author/drew-bedo
There are only three types of mounting flanges; too big, too small and wrong thread!
Time is cruel, but I am very grateful for my extra time.
Tin Can
If Ektascan B\RA is available with clear base, I want some! I don't have time to dig for it right now. Anyone else seen it?
For me, I could make better looking positives. No blue.
Even more contrast?
Change of blue filter effect of blue tint.
I guess we will never know....
Tin Can
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