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

[Kevin Harding]

I can't read Chinese although I work with a team in China who could probably translate it.
In the mean time I cheated and used my phone to translate from the picture.
The first lines basically says something about medical use X-ray standard dental film and the bottom line is the name of the manufacturer which is...
Tianjin Kang Chinese Health Materials Ltd

Good luck

I was going to reply and say exactly this. Top line just says Dental X-Ray Film and the bottom line is the company of manufacture. No indication of ISO or processing instructions in Chinese.

[seezee]

I was going to reply and say exactly this. Top line just says Dental X-Ray Film and the bottom line is the company of manufacture. No indication of ISO or processing instructions in Chinese.

Don't expect to see ISO information. It's not photographic film; why would it have a speed rating using a standard applicable only to photography?

As to the packaging, the Carestream products available in the US & Europe come in a pasteboard box with a thick, opaque, plastic inner bag. Certainly no lead.

[Kevin Harding]

Don't expect to see ISO information. It's not photographic film; why would it have a speed rating using a standard applicable only to photography?

I used incorrect terminology but was merely attempting to respond to the original question of "If the packet colours do not follow international standards to denote the speed band I have to look at the packaging." Should have stated speed band, I suppose.

[Neil Purling]

For medical purposes I believe the correct exposure is given thus: Anode voltage & current flow in the X ray tube + time.
Where sensitivity to X radiation is concerned the difference between bands D and F is that F is only 60% faster. For my purposes the differences are probably meaningless.
I have put films in two 35mm cameras and I will expose one at 50 ASA and the other at 25, developing in Rodinal 1:100 for 7 min and look at the highlights & mids before making a change.
That is unless anyone here believes I ought to try a different dilution/time combination.

[premortho]

I would expose two extra frames, and develop by inspection. Under a red lamp. That way you will learn if your developer concentration is useful to you. When I try a new to me film, I adjust the concentration of Rodinal to water until I get good results at around 10 minutes. Any time will work, but going for longer times means you will have better control over contrast.

For medical purposes I believe the correct exposure is given thus: Anode voltage & current flow in the X ray tube + time.
Where sensitivity to X radiation is concerned the difference between bands D and F is that F is only 60% faster. For my purposes the differences are probably meaningless.
I have put films in two 35mm cameras and I will expose one at 50 ASA and the other at 25, developing in Rodinal 1:100 for 7 min and look at the highlights & mids before making a change.
That is unless anyone here believes I ought to try a different dilution/time combination.

[mdarnton]

I second the develop by inspection idea. I fought through a lot of trial and error initially that would have been rapidly resolved if I'd had the red light in there helping. When I switched developers recently, the whole problem of development got solved in one batch. A red LED bulb only costs about three dollars, and is well worth the expenditure on several different levels.

[Neil Purling]

I received some 4"x4" X-ray film: Crontex MRF 21 Plus & loaded it into some holders. I never heard of the film, so i assume it is double-sided unless a Forum member knows for sure

The person also sent me some Kodak Ultra Speed (D). The stuff is in the same coloured plastic pockets as the Tianjin made stuff I got.
When I referred to lead foil I meant within each individual film pocket. It is behind the film if facing the proper way. The foil bears impressions of zig-zag lines that will be impressed upon the radiograph if the film is exposed the wrong way around.

I haven't trays to develope the film under safelight, yet. I believe that I need trays with a totally smooth bottom or to use an insert.
I am used to my Fink-Roselieve Yanke type tank to develope the 4x4 inch Crontek.
I wonder if food service trays would do for the dental film? As long as the bottom is flat & smooth.

[Jim Noel]

I received some 4"x4" X-ray film: Crontex MRF 21 Plus & loaded it into some holders. I never heard of the film, so i assume it is double-sided unless a Forum member knows for sure

The person also sent me some Kodak Ultra Speed (D). The stuff is in the same coloured plastic pockets as the Tianjin made stuff I got.
When I referred to lead foil I meant within each individual film pocket. It is behind the film if facing the proper way. The foil bears impressions of zig-zag lines that will be impressed upon the radiograph if the film is exposed the wrong way around.

I haven't trays to develope the film under safelight, yet. I believe that I need trays with a totally smooth bottom or to use an insert.
I am used to my Fink-Roselieve Yanke type tank to develope the 4x4 inch Crontek.
I wonder if food service trays would do for the dental film? As long as the bottom is flat & smooth.

The food service trays will wok if they are plastic, or a high grade stainless steel.

[Neil Purling]

I got two 8x4.2" trays from an electronics emporium.They are meant to be used when etching printed circuit boards and are flat bottomed.
I can tape a bin bag over the window at night and Bob's yer uncle. I have a clockwork timer with a ringing bell in the event my red LED lights aren't as safe as hoped. I will test by developing a blank film I left out for 5 min. That should include loading & unloading a holder and the time in the processing cycle making inspections.
If you are tray developing do you only have the light on to inspect progress & switch off again? I am looking at a time between 7 and 10 min in Rodinal, adjusting dilution as the results suggest. I was going to start at 1:100 and dilute further if needed.

Has anyone heard of that Crontex MRF 21 Plus? The provider mentioned 80 ASA for 3 min in ID11 at 22C in a tray, but I prefer Rodinal.

[Fr. Mark]

I've only handled 2 kinds of XRay film a double sided and a single sided. Cxs green a Ektascan B/RA which has an anti halation backing. The developer soluble backing is blackish and the emulsion is pink/light colored. Double sided is pink/light both sides.

Rodinal 1:100 might be a place to start with film exposed mid day as if ASA100. There are dozens of developing schemes in this thread though.