Infos about 8x10 in. Carestream x-ray film

[Mos]

Hi everybody,

My name is Gerardo, I'm a young photographer from Italy. I'm new here, I hope I'm not making any mistakes.
I've always been into Medium Format but, few days ago, I bought a nice 9x12 plate camera from the '20, an ICA Trona 210 with a 13.5cm Carl Zeiss Tessar in compur shutter. I'd like to run some tests but, where I live, I can't really find 9x12 film but Fomapan 100. I read, in this very forum, the possibility to use X-ray medical film. Most of you, as I understand, are using this option to reduce the costs in ULF photography. I'm intended to do the opposite so I'd like to ask some questions:

Here is the film i found from a local store, identical to this one, but even cheaper:
https://www.zzmedical.com/8x10-in-carestream-kodak-x-ray-film.html

The questions are:

1) I have to cut the film, but how should I do that? The film is orthochromatic so I think I should work under a red safelight, am i right? Any precautions?
2) Is the above-mentioned film sensitive only on one side?
3) Any idea about the ISO sensitivity?
4) What is the difference between CSG Green, CSB Full Speed Blue and CSHB – Half Speed Blue ? Any suggestions about the best option to chose ?
5) I use, to develop my medium format film, only a self-made ABCPyro combined with an Alkaline Fixer. Is this a good option to develop the Kodak Carestream or not? Any indications about times?
6) Because the film is orthochromatic can I develop it in trays under the red safelight or should I use, for example, tubes?

That's all, thanks in advance to anyone is going to answer and sorry for my poor english!


Best Regards;

Gerardo

[Alan9940]

There is a long, long discussion of x-ray here:

http://www.largeformatphotography.info/forum/showthread.php?48099-Use-of-X-ray-film-technical-discussion-with-example-images/

Lots of technical information which I think will answer most of your questions.

[Neil Purling]

Glass plates were probably thicker than film and you may need to insert something else in the plate holders in order the sheet film is kept totally flat.
I believe that the correct safe-light for X-ray film is a ruby-red colour, not like that used with prints. X ray film is usually double-sided unless it says otherwise on the box.
The X ray film can be cut down from larger sheets in a darkroom with a rotary trimmer. You can do this in absolute darkness if you have first practiced with some artists card beforehand, so you get perfectly even sheets of the correct size.

I think that you should tell us about how you intend developing the film. As the Foma is panchromatic you would have to develope that in total darkness if using trays or use a daylight tank. That tank would still need to be loaded in total darkness, you can use a dark-bag.
You have developed B&W film before? Shoot the Foma & when you have confidence in your technique you can consider graduating to X ray film.

[Sean Mac]

Hi,

get things good with the Fomapan first I think.

Green carestream is the place to start. Sensitive on both sides.

http://sergeirodionov.com/x-ray-film-photography/ ...worth checking out:)

Ask questions on the "Big Thread". You will get help there.

Your english is fine.

Welcome to the forum:)

[Mos]

There is a long, long discussion of x-ray here:

http://www.largeformatphotography.info/forum/showthread.php?48099-Use-of-X-ray-film-technical-discussion-with-example-images/

Lots of technical information which I think will answer most of your questions.

Thank you, Alan!

[Mos]

Glass plates were probably thicker than film and you may need to insert something else in the plate holders in order the sheet film is kept totally flat.
I believe that the correct safe-light for X-ray film is a ruby-red colour, not like that used with prints. X ray film is usually double-sided unless it says otherwise on the box.
The X ray film can be cut down from larger sheets in a darkroom with a rotary trimmer. You can do this in absolute darkness if you have first practiced with some artists card beforehand, so you get perfectly even sheets of the correct size.

I think that you should tell us about how you intend developing the film. As the Foma is panchromatic you would have to develope that in total darkness if using trays or use a daylight tank. That tank would still need to be loaded in total darkness, you can use a dark-bag.
You have developed B&W film before? Shoot the Foma & when you have confidence in your technique you can consider graduating to X ray film.

Thank you for your answer, Neil!

So, I know about the thickness of the glass plate holder but they were provided with a kind of internal adapter for sheet film!

I always thought that the usual darkroom red safe light was ok also for handling the film, not only for prints. Thank you for this precious advice! Can you give me more information about this safe-light?


Despite my young age ( I am 20 years old) I've already developed lots of film, mostly 120mm with self made ABC Pyro as I said in my first message. I know that Foma is panchromatic, and I would have never developed it under any kind of light but, because I do not have a tank for 9x12, I thought that I could develop X-Ray orthochromatic film under a proper safe light in trays, for simplicity and to achieve a better control of the process.
Eventually I understand from the link posted by Sean Mac that this procedure is actually possible even if someone prefer to operate in complete darkness.

Anyway I think it's better to get some practice in developing Foma first. :)


Thank a lot again,
Have a nice day


Gerardo

[Mos]

Hi,

get things good with the Fomapan first I think.

Green carestream is the place to start. Sensitive on both sides.

http://sergeirodionov.com/x-ray-film-photography/ ...worth checking out:)

Ask questions on the "Big Thread". You will get help there.

Your english is fine.

Welcome to the forum:)

Hi Sean,

Thank you very much, thanks to your link I get most of the answer I was looking for!

I will surly post any other question in the Big thread.

You too have a nice day,

Bye
Gerardo

[Tim Meisburger]

Yes, you can develop by inspection under a safelight, and cut the film under a safelight.

[Mos]

Yes, you can develop by inspection under a safelight, and cut the film under a safelight.



Hi Tim,

Thank you for your answer! Do you know something about the proper red-light mentioned by Neil? I only know the usual inactinic lights: the red one and the yellow-green (this last one obviously not usable for orthochromatic film! )

[John Kasaian]

For an ortho safelight I use a short string of red led Christmas lights I bought on sale. It gives the place a festive atmosphere.

[Mos]

For an ortho safelight I use a short string of red led Christmas lights I bought on sale. It gives the place a festive atmosphere.

Hi John,

Thank you for the idea, it's the first time I heard about someone using Christmas light in a darkroom but I like it ! :D
Can you roughly tell me the distance of the leds from the working area?

Thank you again !

[Tin Can]

I will suggest this exact bulb and only this bulb at 4 ft. If the link misses my target you want the RED LED from this source only.

https://www.superbrightleds.com/moreinfo/led-globe/2-watt-g11-globe-bulb-360-degree/440/


Not all LED's are the same, some are just painted red. Check the aspectrum on this bulb, it's how i chose it.

https://www.superbrightleds.com/moreinfo/led-globe/2-watt-g11-globe-bulb-360-degree/440/#/tab/Specifications

[koraks]

Not all LED's are the same, some are just painted red.
Really? That sounds odd to me. Why would anyone take a white led that's much more expensive than a red one and paint it red, in order to sell it as a red led? You know that a white led is generally two blue ones, a red one and a green one on the same die or in the same package, right?

[Tin Can]

Really? That sounds odd to me. Why would anyone take a white led that's much more expensive than a red one and paint it red, in order to sell it as a red led? You know that a white led is generally two blue ones, a red one and a green one on the same die or in the same package, right?

I guess nobody you know would do that.

All I know is, the bulb I recommend does the best job for this application that I know of.

Many have reported here, problems with different RED LED's and I also have found big differences which create fogging problems.

How does your 'advice' further this discussion? What is your exact recommendation?

[koraks]

I simply wondered where your speculation came from, because the issue of different spectra of red LED's has puzzled me for a while since the last time it popped up here. I suspect it has to do with the way the LED's are driven rather than filtration. LED's have very narrow spectra as a result of the underlying physics. However, if you run a bit more current through them close to their maximum capacity, red LED's tend to shift a bit to the green side of the spectrum. This not only impacts color, but also the lifetime of the LED's themselves (although the driver hardware is more likely to be the first that wears out).

So I'm just curious. It furthers the discussion into a direction that interests me. I assumed that's fair game on a forum.

[Tin Can]

I simply wondered where your speculation came from, because the issue of different spectra of red LED's has puzzled me for a while since the last time it popped up here. I suspect it has to do with the way the LED's are driven rather than filtration. LED's have very narrow spectra as a result of the underlying physics. However, if you run a bit more current through them close to their maximum capacity, red LED's tend to shift a bit to the green side of the spectrum. This not only impacts color, but also the lifetime of the LED's themselves (although the driver hardware is more likely to be the first that wears out).

So I'm just curious. It furthers the discussion into a direction that interests me. I assumed that's fair game on a forum.

It's fair game if you explain and don't just point fingers.

I know SOME LED's in the PAST and maybe present, were dyed, which I call paint.

Since you know all about how a LED is made and works, great, but my question stands, how does that knowledge further our usage, in this particular thread and topic.

I AM interested in what you know about other LED's specifically UV LED for Alt Process printing, but that's a different thread. :) Peace

[koraks]

It's fair game if you explain and don't just point fingers.
My apologies if you took it that way.

[Tin Can]

My apologies if you took it that way.

Please, also accept my apology.

I do think we all need to start becoming more polite.

I will try my best. :)

[koraks]

It's alright; I can see how my remark came across as rude; it's been a long day following a slightly too short night. I'm not someone to hold grudges and you're not someone I'm likely to make an exception for ;)

[koraks]

Since Randy is right in that the OP asks for advice, I'll share my thoughts. Be aware that part of it is a matter of opinion and that nobody knows all about every type of x-ray film that's out there. It doesn't help either that data for photographic uses of these films is never supplied by manufacturers, which leaves a lot of room for guesswork and experimentation.



1) I have to cut the film, but how should I do that? The film is orthochromatic so I think I should work under a red safelight, am i right? Any precautions?
I personally use a pair of scissors and a cutting template, which works, but a roller cutter or even a guillotine works quicker and gives neater cuts. Be careful with guillotine cutters in subdued light and I would advise against using them in the dark. As to red safelight: see the posts above. Randy's suggestion is a known-good bulb, but it's costly to order it from the US and have it shipped to Europe. I went with locally sourced red LED bulbs, found out they fogged my film, and proceeded to use just one which I encased and fitted with a rubylith 'filter'. The rubylith cuts out any unwanted light beyond deep red and seems to render any red LED bulb safe for darkroom use. In any case, be cautious with red LED bulbs, as they are known to vary in terms of spectral emissions and there's usually no reliable way of telling if your bulb is 'safe' without actually testing it.


2) Is the above-mentioned film sensitive only on one side?
If it's identical to BR/A, then yes. But if it really is, I cannot tell from the information you have provided. If it is, I'm very much interested in your source, as I'm also in the EU and would be very pleased if I could source it here.


3) Any idea about the ISO sensitivity?
Try 80. It seems to be a safe bet. Most people I have read expose it at 50, 80 or 100. I personally lean towards 50 rather than 100 for the double-sided film I use, both for green- and blue-sensitive.


4) What is the difference between CSG Green, CSB Full Speed Blue and CSHB – Half Speed Blue ? Any suggestions about the best option to chose ?
I can't comment as I haven't come across these specific designations on the film I use. I only know that blue-sensitive is only sensitive to the blue (and UV) part of the spectrum, while green-sensitive film is sensitive to both green and blue light (as well as UV). Having used both green- and blue-sensitive film, I personally don't see much use for blue-sensitive film. For portraits, it's 'special' in the sense that it will emphasize skin defects even more than green-sensitive film (and even that won't produce a perfectly smooth skin unless your model is - well, perfect!). I also found that on the double-sided film I use (which naturally lacks an anti-halation layer), the blue-sensitive kind suffers MUCH more from halation, rendering it more or less unsuitable for scenes with bright lights (including skies, even if they are slightly overcast).


5) I use, to develop my medium format film, only a self-made ABCPyro combined with an Alkaline Fixer. Is this a good option to develop the Kodak Carestream or not? Any indications about times?
Sure, x-ray film can be developed in just about any developer you'd normally use. The development times will depend on developer type, dilution, temperature and agitation. I personally develop x-ray film in (pa)rodinal at a dilution of 1:75 or thereabouts, for 5 to 7 minutes in a tray, one sheet at a time, with continuous agitation. I use double-sided film and therefore I also flip the film every 15 seconds or so. I don't expect this will be necessary with single-sided film. I had lots of issues with uneven development when trying intermittent agitation schemes, which is why I settled on continuous agitation, tilting the tray alternating between the long and the short side, keeping the developer in constant motion across the film surface and in as random a pattern as possible. The purpose of agitation is to refresh the developer at the film surface. This implies that you want to (1) prevent a laminar flow from occurring, as that may cause depleted developer to 'stick' to the film surface and (2) ensure that the replenishment occurs in an even way across the entire film surface. Hence the agitation scheme that alternates between lifting the short and the long side of the tray, which has proven to be effective in preventing higher densities along the edges of the film.


6) Because the film is orthochromatic can I develop it in trays under the red safelight or should I use, for example, tubes?
I develop by sight under red safelight and it works very well for me. It helps me to compensate for differences in exposure, as particularly blue-sensitive film is more sensitive to variations in light temperature than panchromatic or even orthochromatic film. Plus, it's kind of fun to see the image appear in the developer. Another advantage is that you can 'compensate' this way for variations in developer dilution and temperature, so I actually don't measure my developer very precisely when developing x-ray film, nor do I control the water temperature. The obvious disadvantage of developing by sight is that it's not extremely reproducible, as it's pretty hard to judge the exact density and contrast of the negative. The variations are acceptable to me, but if you want to have full control, you have no other option than to work out a calibrated exposure and development scheme, with controlled exposure (including accounting for the light temperature/color during exposure), developer concentration and temperature and agitation scheme. If you go that route, you might as well develop in daylight tanks of some sort, which is perfectly feasible with single-sided film.

Keep in mind that x-ray film scratches very easily, which is particularly a problem with double-sided film. Solutions include accepting the scratches on one side and stripping the emulsion from that side after development and using processing trays with a perfectly smooth and flat bottom to prevent any scratches.

If you could share your source for film, I'd be very interested!

[barnacle]

Regarding the colour of LEDs - they come in two flavours. Some have a semiconductor which outputs a given visible wavelength (660nm seems to be the most common - a deep red) while some use a UV output and a phosphor to give a visible colour. The phosphors rarely have a single line spectrum and though visibly red can have significant output in blue and ultraviolet. That said, red is not *usually* a phosphor type... but the only way to be sure is to check the datasheet for the LED you choose.

For example - the first one I found at 660nm at Farnell - http://uk.farnell.com/kingbright/dlc2-6srd/led-20mm-ultra-red/dp/1142477 - has a data sheet which states that the peak power is at 660nm and a spectrum peak width of 20nm - quite a decent single colour. The graph indicates that the peak is at less than 10% output by 640nm; the graph for Typon DV-G - http://www.typon-roentgen.de/fileadmin/user_upload/roentgen-bender.de/de/typon/Produkte/DV-G_ORTH.pdf - says it's sensitivity is down to 1% by 630nm. I would be happy to use this as a safe light - though I would of course test it before using it in anger!

Neil

[koraks]

Embarrassingly, it seems that most high-powered white leds are in fact phosphor coated leds (UV or blue). Thanks for the, ah, enlightenment, Neil ;)

[barnacle]

Yes, I should have said... red, green, orange, yellow, or blue are *most likely* direct, but white needs to trigger the red, green, and blue photoreceptors in the eye and the cheapest way to do this is with a phosphor.

Also - beware of RGB LEDs unless you are aware of how they are driven; you could be seeing a red through some controller which also allows some small amount of green or blue at the same time.

Neil

(Been investigating light paths of infrared LED/sensor pairs through polycarbonate prisms this week. First step: prove that the IR path is not too different from red, and then, fun with lasers!)