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

[Thodoris Tzalavras]

Thodoris, what a wonderful portrait.

Thanks Randy.

[Thodoris Tzalavras]

Petra tou Romiou, Cyprus.
October 2015.

Speed Graphic 4x5, with Optar 135mm.
Agfa CP G+ film.
Developed in Ilford MG 1+80 at 22C for 8min.
Scan from negative, finished in PS.

[koraks]

Beautiful capture Thodoris, gorgeous light! And a beautiful spot as well. In fact, you're lucky to live in one of the most pretty places I've been to. Gorgeous island with such a variation in landscapes; I'd love to do some LF shooting there.
How did you control the contrast in this image btw? The light is quite challenging for contrasty film such as this.

One from my end: my niece in front of her mother's house.

Green x-ray, 8x10, G-Claron 240/9 wide open. Film rated at ISO 80-ish, preflashed to zone II to get some detail in the black jeans. Developed by eye for about 4 minutes in Rodinal 1+100 with intermittent agitation (5 gentle tilts every 30 seconds or so). Epson 4990 scan with some digital burning and dodging that even I could do in the darkroom if I put myself to it, but I prefer using these negatives for alt processes.

[Thodoris Tzalavras]

How did you control the contrast in this image btw? The light is quite challenging for contrasty film such as this.

First, that's a beautiful portrait.
Light, composition, depth of field, all work perfectly.
Could you elaborate on your pre-flashing technique? I use pre-flashing (in the darkroom) with direct positive paper (another high contrast material), but haven't tried it with x-ray yet.

As for me, for a long time I used x-ray film mostly with pinhole cameras and for fun—developing by inspection in trays. A few months ago I started entertaining the idea of maybe shooting my next actual project on x-ray film, so I did some testing using a diy sensitometer, trying to find a developing scheme that would allow me to develop more than one sheet at a time (and without inspection), while retaining some control over the shape of the characteristic curve, and especially the shoulder. The particular combination of developer, dilution, temperature, and time, that I'm currently using gives me (relatively) consistent and repeatable results. There is some loss though in the shadows, that's why I'm considering pre-flashing.

[koraks]

Thanks; I was really clowning about and I wish for a lens with a wider aperture as I do find the background a bit busy as it is, but I'm going to try and keep my gear acquisition syndrome in check a bit and work with what I've got

Your approach sounds a lot more structured than mine, which really is haphazard and doesn't involve any measurement whatsoever. Nevertheless, I recognize what you say about the shoulder, which can be a bit hard to control with x-ray film. The same with the toe, which is where the problem seems to lie with retaining shadow detail. My current approach is to try and cram as much of the scene as possible into the straight line of the curve (without doing any formal measurements, mind you, so I'm basically winging it) by exposing quite liberally and shortening development. In doing so, I also ran into the problem of shadow detail disappearing, which makes sense given the contraction approach, which would necessitate rating the film at an even lower speed. This would result in rating it as low as ISO25 (or even less in high contrast situations!) and working with very short development times and high dilutions, which have problems of their own (accurate timing, developer exhausting after a single sheet).

That's why I now try and combine contraction with pre-flashing to find an approach that is robust and reliable enough for my sloppy workflow. The portrait above is really the first real test (apart from a still life at home) and it seems to work as well as I'd hope for; there's plenty of shadow detail in the black jeans that I would have never had without pre-flashing.

My pre-flashing technique is pretty straightforward. I took a random household item that was neutral in color, opaque and would fit over the lens. I ended up using a paper cupcake shell, but a white plastic or styrofoam cup would have worked as well, just as a piece fine and light cloth or a bit of frosted (plexi)glass. I guess just about anything should be usable as long as stray light falling onto the lens can be blocked out. I then held the cupcake shell over the lens of my dslr (which usually I use as a light meter, as it has a spot meter function) and took a reading at ISO 100 (it won't go any lower) pointing the camera at the subject from the position of the LF camera, making sure not to cast a shadow onto the cupcake shell. Given the contrast of the scene (moderate, at least the relevant bits), I rated the film at about ISO 80, so I added about 1/3 stop to the reading, which would result in a zone V exposure. I opted to pre-flash for zone II - partly because my initial test showed that there was very little benefit to picking zone III (just added density and therefore a shorter part of the film's straight curve that could be used) and pre-flashing to zone I just doesn't make much of a difference, and partly because that's the general advice I gathered from Adams' The Negative. Subtracting 3 stops from the reading yielded an exposure of about 1/10 at f/9. This was with one stop added for the bellows draw, as I had already positioned and (roughly) focused the LF camera at this point. I put the cupcake shell over the LF lens, put the film holder in, and exposed the sheet at the calculated exposure. Apart from building some base density, the process of measuring and exposing several sheets of film through a cupcake holder of course yielded sufficient hilarity with my subject so that getting her to hold still for the actual exposure was a bit of a challenge.

The one thing I'm not happy with is that I have the impression (but I'm not entirely sure) that the upper half of the image is a bit more dense and less contrasty than the lower half. I wonder if pre-flashing has anything to do with it, but next time I'm going to try a flat pre-flash implement. Then again, it might just as well have been the lighting of the scene that was the cause of this. Or uneven development. With my haphazard approach, it's hard to be sure of anything

[premortho]

I think the background to have just the right amount of out-of-focus for this portrait. I think it is a great portrait. I think you ought to print it, frame it, and give it to the young lady's mother.

Thanks; I was really clowning about and I wish for a lens with a wider aperture as I do find the background a bit busy as it is, but I'm going to try and keep my gear acquisition syndrome in check a bit and work with what I've got

Your approach sounds a lot more structured than mine, which really is haphazard and doesn't involve any measurement whatsoever. Nevertheless, I recognize what you say about the shoulder, which can be a bit hard to control with x-ray film. The same with the toe, which is where the problem seems to lie with retaining shadow detail. My current approach is to try and cram as much of the scene as possible into the straight line of the curve (without doing any formal measurements, mind you, so I'm basically winging it) by exposing quite liberally and shortening development. In doing so, I also ran into the problem of shadow detail disappearing, which makes sense given the contraction approach, which would necessitate rating the film at an even lower speed. This would result in rating it as low as ISO25 (or even less in high contrast situations!) and working with very short development times and high dilutions, which have problems of their own (accurate timing, developer exhausting after a single sheet).

That's why I now try and combine contraction with pre-flashing to find an approach that is robust and reliable enough for my sloppy workflow. The portrait above is really the first real test (apart from a still life at home) and it seems to work as well as I'd hope for; there's plenty of shadow detail in the black jeans that I would have never had without pre-flashing.

My pre-flashing technique is pretty straightforward. I took a random household item that was neutral in color, opaque and would fit over the lens. I ended up using a paper cupcake shell, but a white plastic or styrofoam cup would have worked as well, just as a piece fine and light cloth or a bit of frosted (plexi)glass. I guess just about anything should be usable as long as stray light falling onto the lens can be blocked out. I then held the cupcake shell over the lens of my dslr (which usually I use as a light meter, as it has a spot meter function) and took a reading at ISO 100 (it won't go any lower) pointing the camera at the subject from the position of the LF camera, making sure not to cast a shadow onto the cupcake shell. Given the contrast of the scene (moderate, at least the relevant bits), I rated the film at about ISO 80, so I added about 1/3 stop to the reading, which would result in a zone V exposure. I opted to pre-flash for zone II - partly because my initial test showed that there was very little benefit to picking zone III (just added density and therefore a shorter part of the film's straight curve that could be used) and pre-flashing to zone I just doesn't make much of a difference, and partly because that's the general advice I gathered from Adams' The Negative. Subtracting 3 stops from the reading yielded an exposure of about 1/10 at f/9. This was with one stop added for the bellows draw, as I had already positioned and (roughly) focused the LF camera at this point. I put the cupcake shell over the LF lens, put the film holder in, and exposed the sheet at the calculated exposure. Apart from building some base density, the process of measuring and exposing several sheets of film through a cupcake holder of course yielded sufficient hilarity with my subject so that getting her to hold still for the actual exposure was a bit of a challenge.

The one thing I'm not happy with is that I have the impression (but I'm not entirely sure) that the upper half of the image is a bit more dense and less contrasty than the lower half. I wonder if pre-flashing has anything to do with it, but next time I'm going to try a flat pre-flash implement. Then again, it might just as well have been the lighting of the scene that was the cause of this. Or uneven development. With my haphazard approach, it's hard to be sure of anything

[Andrew O'Neill]

SergeiR, what rotary system are you using? I ask because I can't see how systems such as BTZS tubes or Jobo would allow development to the backside of the film.

SergeiR, could you go over to the other x-ray thread? Thanks!

[koraks]

Thank you premortho, I will do just that!

[Thodoris Tzalavras]

Thanks for sharing koraks. I appreciate it.

Here's an older one, from 2009.
Artist's Studio.
Speed Graphic 4x5"
Pinhole 0.25mm
Focal Length 75mm
f/300
Exposure Time 15min.
Agfa CP G+ at 50asa
Developed by inspection in Rodinal 1+200 at 20C for 12min.
Scan from negative, finished in PS.

[SergeiR]

8x10, Kodak CSG, R09 1:125 rotary 12min

2015-11-18-0003www by Sergei Rodionov, on Flickr