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

Somehow I can’t stop using this decades old grunge stock. It’s so blue the skin of his dark complexion barely registers.

https://farm8.staticflickr.com/7532/...80ba0b38_z.jpg

I think that is a great portrait!

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Originally Posted by towolf

Somehow I can’t stop using this decades old grunge stock. It’s so blue the skin of his dark complexion barely registers.

https://farm8.staticflickr.com/7532/...80ba0b38_z.jpg

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Originally Posted by towolf

Somehow I can’t stop using this decades old grunge stock. It’s so blue the skin of his dark complexion barely registers.

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Considering how dark everything else is - it might be just a lack of light too.

8x10, Kodak CSG , rotary, 8min , 1:125 Adonal, unstripped.

https://farm8.staticflickr.com/7530/...d4805521_o.jpgTypewriter by Sergei Rodionov, on Flickr

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Originally Posted by SergeiR

8x10, Kodak CSG , rotary, 8min , 1:125 Adonal, unstripped.

Typewriter by Sergei Rodionov, on Flickr

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I really like this one, Sergei...

Thank you, Jiri. She finally recovered to point where i can ask her to pose for me again :) So we broke out wee Quadra lights and had a quick revisiting for wet plate we did a little over the year ago, but with film this time ;)

I picked up a box of Fuji HR-S green on ebay for fifteen bucks, and have been burning up this stuff like it's candy. I'm not exactly sure how the various Fuji stocks differ–the datasheets I've found for HR-T and HR-S have basically identical MTF curves and seem to have the same sensitivity. Hopefully HR-T works basically the same, since it seems like I wont be able to find another box of HR-S. I'm impressed with this stuff enough that Ektascan will probably replace Foma 100 in my freezer, for single-sided stuff.

I started tray developing my 5x7s, but it was getting scratched to high hell. I figured out how to cut it without scratching, though I get faint scuff marks from loading/unloading my holders. The septums of the Grafmatic seem to not scratch it, however. I've been cutting sheets down to 4x5 for testing. On a whim, I loaded a print drum with the stuff and developed as I normally would on a motor base. I expected the reverse side emulsion to look terrible and unevenly developed, but most of the time, I get results as consistent as 'real' film. I've burnt a ton of sheets at different EIs and tried a range of different times. I've settled on EI100, 6:30 in 1:100 Rodinal on my motor base. I tried shooting some at 50 and developing longer, and then stripping the reverse side emulsion. This worked decently well, but the resulting negative was incredibly flat and lacking any decent contrast. The double-sided emulsion doesn't really present a sharpness problem for me with 5x7s...it's a little noticeable with 4x5.

Here's a 4x5 test from a projection petzval, when I was figuring out if it would adequately cover or not.

https://farm9.staticflickr.com/8618/...55acef09_c.jpg

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Originally Posted by Peter J. De Smidt

You determine film speed. Shoot a evenly lit black card in shade. Use your best educated guess as to what the EI of the film is. Set that on your meter. Now meter the card and place the resulting value on Zone I, i.e. close down 4 stops from the meter reading. Take the photo. Close down one more stop and take another photo. Open up two stops and take a photo. You now have exposures bracketing your estimated film speed by 1 top over and under. You can do more if you're really unsure, but for 8x10 I'd just do the three. Develop the film using your best guess. Read the negatives with a densitometer. You want Zone 1 to read _at least_ .1 above film base plus fog. I prefer the value to be about .15. Does that correspond to one of your sheets? If it falls between the ranges your sheets give you, estimate the EI value that'll give you what you want. If there's not enough density, do the test again, starting with 2 stops more exposure than the first test. If it's more, do the same but giving 2 stops less for the starting exposure.

Once you have your film speed, do a development test. Photograph an evenly lit blank white card in sunlight. Set the EI you determined on your meter. Meter the card, making sure it's evenly lit. Read your meter and open your lens to 3 stops more than the meter reading, which places that value on Zone VIII. Take two more exposure exactly the same. Develop one of your negatives. For diffusion printing, the value should be about 1.3 above film base plus fog. If you're not there, estimate the change in development. Develop the next sheet, measure, estimate, and develop the last sheet if needed. If you're development is way off, you might have to do it again.

You now have your N development. You can test it by exposing one neg for the black card placing it on Zone I.....

This sounds complicated, but it really isn't. It also doesn't take much time to do.

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Basic photographic sensitometry; what Oliver Gagliani taught in his workshop, except Oliver used .3 neutral density filters to change each stop rather than the aperture. Felt it was more accurate. Also shows why you need a densitometer to shoot B&W right. L

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Originally Posted by hamradio

I picked up a box of Fuji HR-S green on ebay for fifteen bucks, and have been burning up this stuff like it's candy. <snip>

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Looks good!

You folks have inspired me to get my Century No. 9 8x10 portrait camera operational again.

I should add, it's really great being able to work with this stuff under a red safelight. I use a little red LED 'bulb' in my darkroom and experience no fogging at all.

https://www.superbrightleds.com/more...60-degree/440/