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

[Randy]

I have used several brands of the "green sensitive" Xray film (double sided). I generally rate 50 ISO when shooting on sunny days but drop the ISO to 25 on very cloudy / over cast / or late afternoon in the shade. I am processing in trays - Rodinal 1:200 for 6 minutes. For flash, which I have used only once, I used two Sunpak's facing white umbrella reflectors - I just exposed for ISO 50 - came out fine...but...I am not to particular when it comes to exposure - I am happy enough when I get "close".

BTW - when I was processing in HC-110 dil. H, I had to rate same film at ISO 200 on sunny days.

[koraks]

I rate the green stuff at EI 50 and tray develop in pyrocat hd 1+1+100 for 6 to 8 minutes with continuous agitation depending on the highlights. This yields negatives that print well with Van Dyke and scan fine as well. Anything over EI 80 gives too little shadow detail for Van Dyke, but the shadows scan fine up to about EI 125 or 160.

[seezee]

When I was using Ektascan with strobes (Paul C. Buff Einsteins outputting roughly 5600º K light), I rated it at ISO 80. The half-speed-blue Carestream seems to be around ISO 160 under the same conditions. I credit the double emulsion for the speed increase.

[senderoaburrido]

Corran, I'll get to that on wednesday and come back here with some examples.

[Luis-F-S]

Ok, so I'm using 8x10 EB/RA film which I'm rating it at an EI of 80. I'm developing it in HC-110 at a dilution of 1.5 oz per gallon in 1 gallon tanks with 10 sec agitation each minute. My high densities are coming out ok, but the negatives are so wildly contrasty, they're unprintable. I read in several threads back to place shadow details in Zone III-IV and then to adjust development (under develop) for the highlights. Is that what is recomeded? I developed my last batch of film for 2, 4 & 6 min in the 1.5 oz HC-110 to 126.5 water dilution. The 6 min negatives had good highlight values, but the shadow densities were not there. Any suggestions? Thanks, Luis

[Corran]

I'm confused by your statements. You say they are wildly contrasty - so I assumed your highlights were blowing out. But if the 6-minute development has good highlights but no shadows it sounds like you are underexposing and overdeveloping. If so, I would guess you need to shoot at a lower EI, maybe 40-50, and develop 5 minutes or so.

I have no experience with EB/RA or HC-110 so that's just my thoughts with regard to the ol' adage of "expose for the shadows and develop for the highlights"...

[Fr. Mark]

Ektascan B/RA is a single sided ortho film (not blue sensitive only, also green, though it is on a blue background plastic) with an antihalation backing. It's spectral sensitivity falls off after green somewhere toward red. Carestream has a data sheet on it, or did, on the internet somewhere. Like most people I rate it at 80-100 and add exposure (a stop or two or three) for when the light is more red (early/late in the day, tungsten lights. You can develop by inspection under dim red safelights (emphasis on dim: not all red LED's are 100% safe). I use pyrocat HD, though a number of developers work well like Rodinal 1:50 or 1:100 and I tend to develop for New Cyanotypes more than enlarging. Some people find that treating it like Tmax 100 for reciprocity works pretty well. I have no idea what your filter thing does, sorry.

[senderoaburrido]

http://www.spectrumxray.com/sites/de...Ektascan-B.pdf

I found it! The spectral sensitivity graph is towards the bottom of the document. Sensitivity drops off sharply right around 575nm.

http://www.karmalimbo.com/aro/pics/f...%20filters.pdf

And here you can see that the wratten 44a filter isn't far off in transmission, although it does look like I am dealing with a filter factor after all. If I can adjust for that, I might end up getting much more consistent and acceptable results.

[Corran]

Nice find. If I'm reading that right it has about a 3-stop filter factor in overall light? Looking at the Luminous transmission data, which I assume is a percentage, under the #44. I'm ignoring the wavelengths. That means overall transmission of 15.6%?

[Luis-F-S]

I'm confused by your statements. You say they are wildly contrasty - so I assumed your highlights were blowing out.
I have no experience with EB/RA or HC-110 so that's just my thoughts with regard to the ol' adage of "expose for the shadows and develop for the highlights"...

Not just the highlights, there is like nothing on the negative below Zone IV, just film base and Zone VII goes really dense. I tried developing for 2, 4 & 6 min at the very diluted HC-110 concentration, using 1.5 oz developer to 126.5 oz water in 1 gal tanks I guess I need to place my shadows in Zone III or IV, and lower the development time quite a bit. I'll try doing that this week when I get some time. I can't see using less developer than what I'm using. I was just wondering if anyone had achieved good results with the EB/RA film and HC-110. I had also tried developing it with Rodinal with similar unacceptable results.