X-Ray Film Reciprocity Effect

[Andrew O'Neill]

Incase anyone who uses x-ray film particularly CSX green latitude, here are some curves showing the effect of long exposures.

The 1/8th sec curve represents normal. Some development compensation will most likely be needed as well, starting at the 10 second mark.

 

[Andrew O'Neill]

Exposures were made under an enlarger with a 31 step stouffer wedge. Film developed in Rodinol 1+50 in a tray.

 

[Vaughn]

Nice curves, but how does the rate of failure relate to conventional films and TMax films? Just so that I can wrap my poor brain arounf it!

Vaughn

 

[Andrew O'Neill]

Compared to X-Ray film:

HP5+: 1s give 1/3rd stop more; 10s give 1.5x; 100s give 4x more exposure
No development compensation required.


TMY-2: 1s no compensation; 10s give 1.2x (1/3rd stop); 100s 4x more.
No development compensation required.

 

[Andrew O'Neill]

Here is a rough tonal/colour sensitivity comparison between X-ray and TMY-2.
Green does appear slightly lighter and darker for yellow and beyond.
Tonally, TMY-2 is much much nicer. With the use of filters (#58 green filter for example) one could pretty much get it to look like the x-ray films colour response. Just with much nicer tonalities and sharpness.
I do not have a film scanner, so please excuse the poor quality.

 

[Andrew O'Neill]

After playing around with this film some more, it will not become my main film. I'll stick with HP5 and Timmy-2. I like smooth tonalities, sharpness, decent reciprocity characteristics, and a film that won't scratch so easily.

 

[Andrew O'Neill]

Four years later, and I'm still using x-ray film both double-side green and single-sided blue. If you are careful, you can avoid scratches, even with flat-bottomed trays (which I prefer to use). Not my main film, but nice to have in certain situations.

This was exposed on double-sided green latitude, unstripped. I prefer not to as a stripped neg's tones are mushy. Yes, the stripped neg is a tad sharper, but grain is more noticeable. To my eye, unstripped looks great and you only notice the softness in side-by-side comparisons. All of this is my opinion, of course!

 

[BetterSense]

Under incandescent lighting, with exposures of 5-30 seconds, I found Green Latitude to be significantly faster than Foma 100. Like several stops faster. Foma 100 has legendarily bad reciprocity failure, but I find it interesting that even Xray film is better!

 

[Toffle]

Thanks for this, Andrew. I've been cutting Fuji HR-T Green 8x10 down to 4x5 for the last year or so with some really good results. It's good to have some clue about reciprocity performance on really long exposures. It seems to go very well with my pinhole work, but I've had a couple of longer exposures that fell off the chart, so to speak. On the other end of the scale, I've had difficulty with exposures under bright blue skies. I generally get good results at ISO 50, but under high UV situations, it appears much faster. Do you have any insights into the characteristics of this film?

Cheers,
Tom

 

[Tom1956]

Thread marked. Thank you for your work.

 

[Dr Croubie]

On the other end of the scale, I've had difficulty with exposures under bright blue skies. I generally get good results at ISO 50, but under high UV situations, it appears much faster.

Is that with or without a UV filter (or any other filters) in place?

 

[Toffle]

Is that with or without a UV filter (or any other filters) in place?

No filters in place. I guess technically I could use filters with my pinhole camera, but I've never tried.

 

[SawyerK]

Thanks for the curves. I've been building large pinhole cameras and shooting CXS green sensitive xray film but my exposures are so long, reciprocity was about to beat me. As far as developing, have you had better luck tray processing or tank processing. I'm shooting 14x17" sheets so tray processing is better for me, but I can't figure out how to control streaking. My film looks more like tye dye than else. I've been using GBX developer and replenisher and Sprint but I can't figure it out, have you ahd any luck with Sprint/d76?

 

[Andrew O'Neill]

You are very welcome! I prefer flat-bottomed trays for both 8x10 and 14x17. I've never had problems with streaking or mottling. I've not used those developers for x-ray, so I cannot comment. I have used D-76 in the past on conventional films, and I'm quite certain it would work with x-ray, diluted more than usual. I always give quite vigorous agitation, for the first 30 seconds, then 5 sec every minute. Make sure the film is completely covered with developer in the tray. My rule is as deep as the first knuckle on my middle finger...which is about an inch.

 

[Andrew O'Neill]

Still working with this stuff. Switched over to D-23 diluted 1+2. Very nice, clean negatives that print well in carbon. Green latitude xray. EI 100. Almost always with a yellow #15 filter or green if I remember to bring it!

 

[Cholentpot]

I've been using Min-R in rodinal 1:100. Scratch it up every time I use it. It's cheap and fun to use though and I don't worry about wasting film.

 

[Andrew O'Neill]

I've been using Min-R in rodinal 1:100. Scratch it up every time I use it. It's cheap and fun to use though and I don't worry about wasting film.

I use double-sided xray in a flat-bottomed tray. No scratches. Starting out with this stuff back in 2008, scratching was a major issue. I tried ribbed trays with glass on the bottom. Ziplock bag technique. Film hangers (hated them as they introduced awful surge marks along the edges). Gentle agitation in flat-bottomed tray was the answer. I also use single-sided Ektascan, developed in BTZS tube. This stuff is razor sharp...but I prefer the look of the double-sided green, especially in the rainforest.

 

[Cholentpot]

I use double-sided xray in a flat-bottomed tray. No scratches. Starting out with this stuff back in 2008, scratching was a major issue. I tried ribbed trays with glass on the bottom. Ziplock bag technique. Film hangers (hated them as they introduced awful surge marks along the edges). Gentle agitation in flat-bottomed tray was the answer. I also use single-sided Ektascan, developed in BTZS tube. This stuff is razor sharp...but I prefer the look of the double-sided green, especially in the rainforest.

I don't have a proper darkroom. Stearman Press or taco method is what I'm limited to right now.

 

[Andrew O'Neill]

I don't have a proper darkroom. Stearman Press or taco method is what I'm limited to right now.

No clue what Stearman Press is. I would only do the taco method with single sided x-ray.

 

[Cholentpot]

No clue what Stearman Press is. I would only do the taco method with single sided x-ray.

They're a sponsor here. Look at the little blue biplane on the bottom of the page, it'll link you to their website.

 

[laser]

Reciprocity Log Failure (RLF) is only considered in the design of x-ray films from 1/50th of a second to about 1 second. Most x-ray exposures are based on relatively short exposure time. Even in prolonged procedures when a grain is exposed on the film, the duration of that exposure is quite short. There is a relationship between silver grain sensitivity to physical pressure and reciprocity characteristics. Minimization of reciprocity effects results in grains that are sensitive to physical pressure. Due to the nature of how x-ray films are handled most manufacturers will opt to improve the physical abuse resistance in favor of increased RLF.

http://www.makingKODAKfilm.com

 

[Andrew O'Neill]

Reciprocity Log Failure (RLF) is only considered in the design of x-ray films from 1/50th of a second to about 1 second. Most x-ray exposures are based on relatively short exposure time. Even in prolonged procedures when a grain is exposed on the film, the duration of that exposure is quite short. There is a relationship between silver grain sensitivity to physical pressure and reciprocity characteristics. Minimization of reciprocity effects results in grains that are sensitive to physical pressure. Due to the nature of how x-ray films are handled most manufacturers will opt to improve the physical abuse resistance in favor of increased RLF.

http://www.makingKODAKfilm.com

Very interesting. Since we use this film for pictorial use, we cannot ignore reciprocity effect. I've been using this film for a while, and had a love/hate relationship... until recently. I quite like this stuff. It's fantastic for alt processes! Love it in D-23 1+1.

 

[ic-racer]

Did not see the OP in 2010, but what is the Y axis? Or are there 4 different Y axes because you raised the enlarger head each time to decrease intensity by mathematical calculation or incident or reflected meter or white channel of color analyzer or counting clicks on the lens aperture? I'd like to make some similar graphs for Shanghai and wanted to use the same methodology.

Or have you ever tested Shanghai?

 

[Andrew O'Neill]

Did not see the OP in 2010, but what is the Y axis? Or are there 4 different Y axes because you raised the enlarger head each time to decrease intensity by mathematical calculation or incident or reflected meter or white channel of color analyzer or counting clicks on the lens aperture? I'd like to make some similar graphs for Shanghai and wanted to use the same methodology.

Or have you ever tested Shanghai?

Enlarger head stayed at the same height. I used ND filters for 10 sec and 100 sec exposures. I have characteristic curves I made for Shanghai, but never bothered testing it for reciprocity. I do have an excellent chart though, from Shanghai that I have tested in the field. I also have reciprocity data I generated years ago for HP5, TMY, and Acros (my data for Acros matches Fuji's).

 

[ic-racer]

Ok, ND filters. Thank you!