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

[Corran]

I discovered today that my Fuji Super HR-T green-sensitive x-ray film apparently has pretty good reciprocity characteristics. I shot a couple of 30-second exposures with no extra compensation and they came out perfectly. I don't know if in this huge thread anyone has done any reciprocity tests so I thought I would post this. I will be trying out some longer exposures to see just how good this stuff is. I'm surprised it was even good out to 30 seconds.

[Jay DeFehr]

I've tried the drums. I get even development but those ribs scratch the hell out of the emulsion.

I've stuck with glass in a tray, stand develop in Dektol. 1 minute. Only problem is when the negative suctions to the glass. I've been planning to nip the corners from the glass to give me somewhere to grasp. But the only time I remember I want to do it, is when I'm cursing as the clock keeps ticking on me. 20 extra seconds (still have to be gentle to not scratch the emulsion) is a long time when you have a 1 minute development time. Heh. Contrast ramps up big time on me.

Eventually you have to panick. Heh. And then you scratch as you can see in the top corner on that CXS Half-Speed Blue.

Attachment 69516

Wayne,

Just move the glass with the film, from the developer tray into the stop. It's much easier to handle a plate than a sheet of film.

[Jim Fitzgerald]

I discovered today that my Fuji Super HR-T green-sensitive x-ray film apparently has pretty good reciprocity characteristics. I shot a couple of 30-second exposures with no extra compensation and they came out perfectly. I don't know if in this huge thread anyone has done any reciprocity tests so I thought I would post this. I will be trying out some longer exposures to see just how good this stuff is. I'm surprised it was even good out to 30 seconds.

I have recently experienced the same thing with my green sensitive x-ray film. I was adding reciprocity from a post that Andrew O'neil (I think) put up about this. I have gone back to not adding any and my negatives are much better. After about 30 seconds I just doubled the exposure and it seemed to work fine. X-ray film is a totally different animal.... at least I think so.

[Vaughn]

Jim, have you used the Adox 25 ASA film? We used a few sheets in the redwoods. Rated it at 25, gave a one minute metered exposure exposures at 2min, 4min, and 8min -- as I had heard it had steep reciprocity failure. The 2 min exposure was printable, the 4 and 8 minutes were not over-dense and should have been usable, but the image fell apart in the highlights. I had also heard that the film did not take well with over-exposure...now I know why! Too much exposure (as with the pure white branches in the sun in the background of this image) causes the film to spread out the exposure. Either the anti-halation coating can't handle it, or there is some sort of bleeding of light (or chemical reaction) in the emulsion from over-exposed areas into the surrounding areas of the emulsion.

But the result was that these highly defined bright branches became visual mush. I certainly learn my lesson with that film! The reciprocity failure was in the "normal" range and the 2min exposure had enough shadow detail (placed on Zone III). It will make exposing high SBR situations such as we had in the redwoods tricky.

Has anyone seen anything like this in X-ray film? It has no anti-halation layer...and even more, sticks another emulsion where the anit-hal layer would be! Has anyone seen a limit to the amount of exposure the types of X-ray films can take before there is some loss of definition in the highlights (best seen when a white and a black are next to each other)?

Another thought -- perhaps a pyro type developer might help with the Adox 25. If the spread of exposure around over-exposed areas in the emulsion is more from a chemical reaction happening during development that bleeds into or contaminates the areas in the emulsion around it, then a tanning developer might harden the emulsion enough to prevent this "bleeding" within the emulsion.

Jim...have you noticed any difference in x-ray negs developed with non-pyro and with pyro developers?

I got to get out of the house!

Vaughn

[Andrew O'Neill]

After about 30 seconds I just doubled the exposure and it seemed to work fine

.

So then you are compensating then, Jim?
I still use the reciprocity data that I posted a while back. I prefer my shadows to be full of light, rather than black voids. I give compensation up to 32 seconds. After that, I don't bother, as the film's DR seems to flatten out resulting in negatives that look grossly overexposed. My tests have shown that the green stuff that I use has bad reciprocity characteristics. The curves don't lie... but then it does come down to the image and personal preferences.

Andrew O'Neill

[Corran]

Andrew, exactly what film are you using? From my reading it seems that the various films from Fuji, Kodak, Agfa, and generic brands too all vary to a broad degree, not to mention with what development techniques are used!

I did not know you had done some reciprocity tests on x-ray film. Do you have a link to these?

I can categorically state that with a 30-second exposure on the Fuji Super HR-T there was NO loss of shadow detail, for me, rated @ ISO 50, developed in a BTZS tube w/ Rodinal 1:100 for 6:30 and stripped. Which is great news for me because I'm stopping down a lot and having resultant longer exposures with 21"/28" lenses.

[Vaughn]

I have only used the blue-sensitive (Agfa) and I was surprised at how the differently it reacts in different light situations. Tests at 400 and at 800ASA, taken as portraits in open shade, the 400ASA yielded very dense, over-exposed negs. At 800 the negs were dense, but very printable. These first tests were developed at the hospital. The light on the subject(s) was almost all blue light from the sky.

Under the redwoods, the working ASA seemed to be closer to 100. I used 400 and had under-exposed negs but originally blamed in of poor reciprocity. But it just might be the difference in the color of the light that is lighting the scene. So when I have exposed this type of x-ray film, I take note if there is a lot of blue sky adding light to the scene and adjust accordingly.

Vaughn

[Richard Rankin]

For all those who were wondering if double-sided x-ray film could be processed in a drum (and for those who warned against it), I'm pleased to report that I actually tried two 8x10 Agfa Green X-ray film sheets just now is my 11x14 Unicolor Print Processing Drum and I had--judging by the negs that are drying now--even development. No mottling, no streaks.This kind of drum has ridges on the wall that keeps the film suspended for flow on both sides. I figured that especially since the x-ray film is thin and lighter than normal film, it would float fine. It did. The results look identical to the tray processing I've done.

When I tried that, I had lines on the rear of the neg left where they touched the ribs. I assume that the emulsion touching the ribs wasn't removed completely, thus leaving the lines. But each time I tried it, I got the same result.

Richard

[Jim Fitzgerald]

Vaughn, I have used Efke 25 for years in all my formats except 14x17. The only problem I've had with bleeding of the highlights is when I shoot a heavily backlit scene. I have an image from Yosemite that I will eventually nail that has highlight density that is about 3.30. I over developed the neg a bit so exposure time in the Nuarc is at 1300 units! That is pushing 40 minutes. The detail in the neg is amazing and it is there I just have to print it right. I always use Pyrocat-HD with my Efke and with the x-ray film I use Pyro or D-76 and I have not noticed much difference at least visually. Printing the x-ray negs seems to be the same regardless of developer. I believe that it is true that if you over expose the Adox/ Efke you will build density real fast to a point of where it is just not usable. Some of my best negative shot in the Redwoods when we last worked together were shot on Efke 25 with the 8x20. 10 minute exposures at F-64 and the neg's and carbon prints are some of my best. I love using this film in the Redwoods as the slow exposure allows the light to wrap around the scene and give an added 3-d quality to the light. It was great when there was no wind to boot, remember!!

Andrew, maybe it is the way I meter? I try to keep my shadows open and full of light as well. Zone III and let the blacks fall where I wish them to. Using the Pyro I know I can hold the highlights. Seems like if I give it to much exposure I loose all of my contrast. Could be the lens, ISO rating and the different light that I shoot in. I'm not one for extensive testing and I think it is me as curves do not lie, I agree. I did test a still life set up using my Fresnel and a CFL for light and noticed that the negs were virtually the same. I believe for me I have been overexposing my film as I rate it at 80. Maybe Vaughn is right in that it has different speeds in different lighting situations.

[Andrew O'Neill]

Seems like if I give it to much exposure I loose all of my contrast.

Very true! I found this out as well. Jim, if they way you work works, then keep doing it. I'm not crazy about testing but I do feel that it is necessary to really know your materials.