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Greg
7-Nov-2016, 17:29
Does anyone use the Zone System with X-Ray film? Seems as would be a good combination for producing negatives with a high density range for alternative printing... especially when shooting low contrast scenes.

My Zone System calibration is a combination of George DeWolfe's film attenuator and Arnold Gassen's parametric density plottings... guess that dates me.

Don't mind going through the Zone testings again for the nth time, but am looking for a X-Ray film & developer combination that I can start off with. Up to now have only been using X-Ray film for testing lenses.

thanks

koraks
8-Nov-2016, 01:16
I'm not aware of anyone who has done systematic testing with xray film to the extent that reliable N, N+ and N- data are available. If you were to embark on the nth testing spree, I can only recommend using a type of film that is most likely to remain available for an extended period of time.

Jim Noel
8-Nov-2016, 09:13
The Zone System is so automatic I immediately began to apply it when I tested my first batch of x-ray film just as I do with all new batches of film. For me it is the only practical way to approach a new film or developer. I make rudimentary notes which mean a lot to me,but would be meaningless to anyone else. With x-ray or any other orthochromatic film the light source,time of day and weather conditions become muchmore important than with panchromatic film.

Greg
8-Nov-2016, 16:44
I'll have to take it that few if anyone are/is using the Zone System with X-Ray film. Decided to keep on shooting Ilford FP-4 Plus and process for contact printing on FB paper. For the images I choose to print with an alternative process (Silver or Platinum/Palladium), I'll keep on making digital negatives. Have been using the technique described in Dan Burkholder's book: The New Inkjet Negative Companion with an amazing amount of success and consistency.

neil poulsen
9-Nov-2016, 05:11
What is there about X-Ray film that would inhibit one from testing film speed and determining different developments for different scene contrasts?

Greg
9-Nov-2016, 16:40
What is there about X-Ray film that would inhibit one from testing film speed and determining different developments for different scene contrasts?

What is there about X-Ray film that would inhibit one from testing film speed and determining different developments for different scene contrasts?

One can test the film speed of X-Ray film and also determine different development times.

I studied Photographic Sensitometry at RIT under Hollis Todd back in the 1970s. Consulted his textbook and came up with the following variables:
1. "The spectral sensitivity curves of photocells (used in exposure meters) do not come close to that of the eye, and none approximate the spectral sensitivity of any film whatever"... unless the photocells are "Properly filtered" Remember doing tests in class to show this.
2. Orthochromatic nature of the film further makes exposure determination with exposure meters even less accurate, obviously especially with the red end of the visible spectrum.
3. I expose my film with step wedges under a standardized 3,200 degree Kelvin light source. The X-Ray film would be shot outside in sunlight. With Panchromatic films, testing and filming under two different light sources is within the margin of error, but with Orthchromatic film rather think that there would be a lot more inherent errors.

I remember plotting D log E (or possibly H & D... my memory fails me here) curves for Orthchromatic and IR film and we ran into all kinds of problems trying to compare them to D log E curves for Panchromatic film.

As Jim stated: "With x-ray or any other orthochromatic film the light source, time of day and weather conditions become much more important than with panchromatic film" Studious note taking seems to be the way to go.

Now remember back in the 1970s at RIT when shooting LF and ULF formats, we used Kodak 2566 Reproduction film (we were students and it was free) and developed it to get full tonal range negatives. We kept detailed notes on the exposures we used which just practically worked. Metering scenes was far less accurate. I postulate that this would be the same with X-Ray film.

The above is from memory of that class I took with Hollis Todd some 43 years ago so can't vouch that it's totally accurate...

Mark Sampson
9-Nov-2016, 18:42
Well, *someone's* got their marching orders. As the late Fred Picker would have said, "TRY IT". And don't forget to share your results!

neil poulsen
9-Nov-2016, 18:49
What is there about X-Ray film that would inhibit one from testing film speed and determining different developments for different scene contrasts?

One can test the film speed of X-Ray film and also determine different development times . . .



Makes sense.

Similarly I guess, if densitometer readings are taken from film that will be used to print ptpd, then a UV densitometer is needed.

j.e.simmons
10-Nov-2016, 05:55
I did BTZS testing with green X-ray film. It seems to work as with traditional film, though I will say the development times for various SBRs are closer together than for Tri-X, for instance.
As Fred said, try it. As Sam Burris says, try everything - use what works.

Greg
10-Nov-2016, 07:26
I did BTZS testing with green X-ray film. It seems to work as with traditional film, though I will say the development times for various SBRs are closer together than for Tri-X, for instance.
As Fred said, try it. As Sam Burris says, try everything - use what works.

Thanks... this gives me a starting point for development times. I usually run my test with 5, 10, 15, 20, 25, and 30 minute development times. From what you stated, will cut the differences in times way down. Will see how it goes...

koraks
10-Nov-2016, 12:17
I did BTZS testing with green X-ray film. It seems to work as with traditional film, though I will say the development times for various SBRs are closer together than for Tri-X, for instance.
As Fred said, try it. As Sam Burris says, try everything - use what works.
I didn't do anything even close to what you did, but I did do some informal trial & error recently. It seems to confirm what you write: development times with quite pronounced differences are spaced not too far from each other. See my post here (http://www.largeformatphotography.info/forum/showthread.php?48099-Use-of-X-ray-film-technical-discussion-with-example-images&p=1359973&viewfull=1#post1359973). Since I don't have access to a densitometer and I don't have the patience (or clear purpose) to test it the long way (through printing), my testing won't go much further than this in terms of accuracy. However, I do plan on doing some more trials to get a feel for how to deal with high vs. low contrast situations. I guesstimate that for contraction negatives, this will involve decreasing the EI quite drastically while reducing development time only marginally. On the other hand, I suppose that expansion will not require that much less exposure (to preserve shadow detail) while again increasing development time by a limited amount. I have a feeling (for lack of actual measurement) that the window is quite narrow and that e.g. N-2 may be already stretching things. But that's just gut feeling and of not much use to anyone in this thread, I fear. It's all I got for now.

Greg
10-Nov-2016, 17:34
Finally talked with another photographer who did a Zone system calibration with X-Ray film. He confirmed what has been said in this thread that "development times with quite pronounced differences are spaced not too far from each other." His development times for N-2, N-1, N, N+1, and N+2 very, very close together and the ISO/ASA greatly changed with the different development times. In the end he went back to shooting conventional panchromatic film

koraks
11-Nov-2016, 01:15
Greg, thanks for this addition; I suspected as much, and it's good to get some confirmation. Sadly, it also means that contraction and expansion will only be possible to a limited extent and with limited accuracy. Add to this the issue of spectral response and I can very well imagine pepper giving up with xray for the purpose of real zone system work.