If Xray film demand is holding up Kodak made a mistake selling it off?
Probably. Perez used it as a quick way to generate cash since he didn't care about it. He had made that clear right out of the chute. Profits from that division were in the billions of dollars per year, even as demand began to fall. It also enabled Perez to ax a lot of people at one shot, although most ended up at Carestream, the company EK sold the x-ray business to, at least for a while.
As far as I knew from my last contacts with Kodak friends that worked in HSD, the Carestream deal was a lot like the Kodak Alaris deal in that Kodak manufactured the film under contract to Carestream and they did the sales and marketing. I see the films are now branded Carestream but they still carry the same EK trademarks such as Ektascan and X-OMAT. I believe Carestream had the rights to the Kodak name for some period of time. Guess they figure no one cared any more. Carestream is not a film company, they are a service oriented outfit. I would have to imagine EK (or former EK people) are still involved somehow.
Latent image keeping wouldn't matter because the film is processed right away. Also, stock turns over pretty quickly because the hospitals don't want to keep it in inventory so storage isn't much of an issue. Imaging is a high profit center so they want that film generating income. It is amazing that it is so cheap compared to regular film.
As PE says, reproducibility of image characteristics for a given technique (or exposure) is key. The technicians are trained to judge exposure to get the density and contrast correct and what is wanted varies by radiologist. They are sometimes looking for minute changes in contrast to read the image, and it is amazing to watch an experienced radiologist and how fast they read images.
There have also been many projects to extend the exposure latitude, another key property, including methods using storage phosphors that are scanned and digitized. All have met with some level of success but most of the image characteristics are still determined by old-fashioned intensifying screens.
The screens are coated with a barium phosphor that is excited by x-rays and fluoresces. That is what creates the image. Contrary to popular belief the film is not primarily exposed by the x-rays. The phosphor intensifying screens are far more efficient than a direct x-ray exposure would be. The most popular screens give off green light which is why many x-ray films are orthochromatic. I would also think that sensitizing dyes play a key role in linking with the characteristics of the phosphor.
Now when Mirko or Simon start talking about how complicated a new emulsion is to get started,I understand a lot better than I did. That's pretty amazing.
If you are into techno-nerd stuff, I find the technology of film to be absolutely fascinating - just read the emulsion making threads here. It's just as high tech as any digital, electronic whiz-bang thing they can come up with. And the amazing part is you can do about 80% of it in your basement. Try that with a digitable camera!
