What ISO is this Xray film???

THERE IS NO ISO
ISO is a standard set of exposure and development criteria for certain pictorial films.
NOT for aerial films, x-ray films, graphic arts films, etc. Not even for "real film" shot by zone systemizers.
In practical terms, you must try some things- exposures and developers, until you achieve results that are acceptable- or until you give up.
Heed what Jim Fitzgerald says above for a start point- he says it all.
I have done the first rounds of testing fast blue but haven't cracked the box of green- I still have to figure out how to not scratch the emulsion- more practice needed.
Whoooooaahh boy I am grumpy this morning- shouldn'ta looked at the so-called news.
Good luck and
regards
Ed

Yeah, Ed, you are semi-correct. But we still need to set the meter at some ISO. :p :D

Ed, anyone who shoots x-ray film and is looking for what speed, developer etc should head the advice of those of us who use it and get the results we are after. So again I say for me and my work flow this is what I do. Set my ISO at 80 for the green sensitive no matter which one I use. ( I have 3 different brands in three different sizes) I meter my shadows to Zone III. I develop in Pyrocat-HD 1:1:100 in tanks for 8x10 and flat bottom trays for 11x14 and 14x17. I pre soak for 3 minutes and then develop with standard agitation( 30 seconds followed by 5 seconds every thirty seconds) for 6-7 minutes depending on the contrast range of the scene. I turn my red safelight on about 4 minutes into development and judge how much development to give. Water stop and fix in TF-4 for 4 minutes. I punch a corner of the film so I know what side of the emulsion was facing the lens and hang to dry. Then I look at the negative and determine if it is good enough to make a carbon print and then I do so. Now, if you want to know how I do the carbons with x-ray negatives then you have to take my workshop! Don't over think this material. It is cheap! The money you save on film can and should go toward more holders! So I say try ISO 80 and fire away! I think this covers it. Oh, if you are using trays to develop make sure you use enough developer. I've not scratched a negative in a very long time. Now I have had a lot of practice with Efke-25.

Vaughn
Shoot I forgot about you folks that live in the rain forest primevel .
I did get a fix for my Pentax meter- from way back in the days of real batteries and ASA [ EI really hehe]
I fixed it figuring I really needed to use a meter for portraits- of which I have done none yet. So much to do, so much screwing around instead of doing it.
So being blessed with sunlight and plenty of it, I'm a sunny sixteen kind of person and probly should be ashamed, but I'm not :>)
Meter? I don't got to show you no steenkeen meter.
regards
Ed

Yeah, my exposure times range from 30 seconds to 30 minutes -- hard to figure with the o' Sunny-Sixteen!

But I could survive without a meter -- it would be "I'd better make this a long exposure...and then triple the time!" LOL!

I'm really looking forward to experimenting with X-ray film. I've become fairly comfortable with ortho lith film, but the extra 3 stops (+/-) of speed will be most welcome!

Jim,

If the film is ortho, why do you use your safe light intermittently? Is your light not completely safe? Or, is the film not strictly ortho? Or some combination of the above?

I shoot this stuff at 100, develop in pyrocat-hd 10ml A + 10ml B + 1000ml water, in a flat bottomed tray with agitation every 30 seconds. I'm using it for carbon printing. Love being able to work with it under safelight.

Am I to understand that this X-ray film is near normal contrast when developed in a normal concentration of a standard developer?

Jay
Several months ago there was a thread
Short answer yes.
And to repeat what I found out back then, and what Jim F said above
Pick an EI- folks have reported 50 to 200- I tried 125 for prints on RC.
Shoot film - it's cheap, no CHEAP
Use your familiar developer for your familiar film you use in the EI range you use.
You'll get results that are pretty close
Change your EI as you see fit- or extend/shorten develope time--or don't if you got results you like in round one. I found that I hit the ballpark pretty easily.
From my perspective Xray should be a LOT easier to tame than litho [I don't think I could], so you should find it really easy

Ed,

Fantastic! Are we talking about the green latitude film, or just the plain green ortho? I'm going to place an order. I had planned to wait until after my move (I'm moving to Seattle after the first), but I don't think I can stand it! Thank you all for the great tips!