Use of X-ray film: technical discussion with example images

[senderoaburrido]

It's more expensive than Carestream or Fuji, but in case anyone is interested, Amazon has Agfa Radiomat now.

Is it double-sided emulsion? Anything unique about it?

[seezee]

Is it double-sided emulsion? Anything unique about it?

Amazon has Radiomat Duplicating, which is 1 sided with anti-halation backing, but the bulk of their offerings are double sided. I have not used any Agfa x-ray, and can't really comment on quality.

[andrewch59]

I have experienced a problem with xray I have not had before. Firstly, I took some xray pics (normal green Agfa at iso 80) of my exhibition setting up. I used a new to me Schneider super angulon 90mm f5.6, 8 second exposure at f22, as the gallery only had led lighting and dimly lit except on the photos.
I went back to my darkroom to develop the first couple, did everything the same and noticed some white specs all over the pic when zooming in. Salt and pepper like, but only problem with white specs. As I use old plastic milk containers I thought perhaps the soup was contaminated with milk residue.
I went back opening night and took a couple more pics, when developing this time I used everything new, including using demineralized water for the developer mixture. The only thing I did different was to use a stop bath. Any ideas on what has caused this? The pics turned out great using the lens, but a bit of a let down zooming in.

[Randy]

Andrew, was this a new box of film or was it an opened box of film you had already used?

I purchased a box of 8X10 green sensitive x-ray film (ebay) several years ago and I probably let it sit for 6-8 months before finally opening it and shot some pics. What I got was tiny circular dots all over each sheet after processing (visible only with a loupe). I figured surely it was my processing but it turned out to be defective film. I even ran tests taking sheets from the center of the stack just to make sure it was not just the end sheets and used fresh everything (chems). Nope, the entire 100 sheet box had what I can only describe as contaminated emulsion.

Mine were tiny dots of increased density in the neg, which translated to small light dots in the prints / scans.

[andrewch59]

Hi Randy, I have been using this box for a while now, so I don't suspect the film at the moment. The dots are not uniform as such, but they have saturated the shot, which makes me think of contamination. A second hand Paterson paper washer was my first thought, but the film get a good rinse under the tap afterward, the only other thing I have done differently is use a stop bath (after reading Ansel Adams "the negative"). The beauty of large format is the resolution, now all I see is snow!

[Randy]

Perplexing Andrew - I guess you just have to eliminate the possible causes. Start with the stop bath...? I don't use stop - have been processing my own film for many years and haven't used stop since the 80's probably, for any of it, 35mm, 120, large format, X-ray...

[koraks]

A strong stop bath may cause pinholes in the emulsion. I've had this happen with x-ray film as well (at least that's my working hypothesis). X-ray film emulsion is very soft and it damages easily. It makes sense to me that hitting the alkaline-soaked emulsion with a strong acid can cause carbon dioxide bubbles within the emulsion, blowing tiny holes in it. If you insist on using a stop bath, try diluting it to 50% or even 25% of its recommended strength - or be like Randy and don't bother with it at all.

[andrewch59]

Thanks Koraks, I have only used a stop bath on two occasions, both being somewhat important to me, should have stuck with my old regime. Its a good opportunity to see if a stop bath is actually detrimental to xray film. Will shoot another in the next few days and let you know if that was the fault.

[seezee]

A strong stop bath may cause pinholes in the emulsion. I've had this happen with x-ray film as well (at least that's my working hypothesis). X-ray film emulsion is very soft and it damages easily. It makes sense to me that hitting the alkaline-soaked emulsion with a strong acid can cause carbon dioxide bubbles within the emulsion, blowing tiny holes in it. If you insist on using a stop bath, try diluting it to 50% or even 25% of its recommended strength - or be like Randy and don't bother with it at all.

Or use a plain water stop bath.

[koraks]

Yup, that's what I do most of the time to limit carry-over of the developer into the fixer. Works fine with xray film.