Re: Use of X-ray film: technical discussion with example images
Quote:
Originally Posted by
mohmadkhatab
You are awesome, man.
Very very great ,,
God bless you ,
- If you allow me ,,
I have some remarks, I hope your chest expanded to listen to it.
Many thanks, Mohmad, for your kind words and for sharing your thoughts. Please allow me to respond on them:
Quote:
I find myself more inclined to use potassium thiocyanate instead of sodium thiosulfate, as it means more accurate results.
- I think that the idea that the first developer is the same as the second developer has proven to be a failure of that idea a lot,
- The first developer should contain potassium thiocyanate or sodium thiosulfate (I prefer the first), while the second developer does not contain this component.
Yes, I agree. The first developer should ideally contain a silver solvent, or alternatively a separate silver solvent process step should be performed before the bleach step. I think the choice between thiocyanate and thiosulfate is perhaps a personal one; why would you prefer thiocyanate?
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- The image still has a lot of silver, as the bleaching is not sufficient, (the time of bleaching is small or the focus of the bleach is weak or both reasons)
I do not think the bleaching was insufficient. It was essentially complete, and this was easily verified visually since bleaching was done under normal light. Additionally, dichromate bleach is always very fast and effective in my experience.
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The second re-exposure was weak as I thought and relied only on completing the steps with room light (as I think), and this is not enough, the second re-exposure should be done in a concentrated manner and preferably chemical and not dependent on room lighting because re-exposure is using Room lighting will not result in equal and equal exposure in all parts of the film, and accordingly, the image will be a hybrid of negative and positive anonymously.
In the image shown, I turned on the room lights after the stop bath and kept them on for processing. Note that my room lights are very bright indeed and exposure to them will fully expose any film, no matter what speed, within a second or so. In a subsequent experiment I reduced the exposure by a controlled one-second exposure to my room light. The effect was identical. This suggests that the fogging exposure was complete in both instances.
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Regarding the re-exposure step.
I support the chemical method.
By adding one gram of tin chloride to the second developer.
Yes, I would prefer a chemical fogging step as well. Sadly, I do not have any tin chloride on hand. I might give it a try with sepia toner, but this of course modifies the image tone and adds some density as well on top of the silver image alone.
As to your question on the equipment: it looks like a grafmatic 4x5" film holder. I have never used them, but as far as I understand, it is basically a standard 4x5" film holder with a little number dial that can be used to identify individual holders by exposing a number on each film sheet. I know that one or more people on this forums use these holders. I don't know in which cameras they may or may not fit. I mostly use Lisco Regal film holders.
Re: Use of X-ray film: technical discussion with example images
Quote:
Originally Posted by
koraks
Many thanks, Mohmad, for your kind words and for sharing your thoughts. Please allow me to respond on them:
Yes, I agree. The first developer should ideally contain a silver solvent, or alternatively a separate silver solvent process step should be performed before the bleach step. I think the choice between thiocyanate and thiosulfate is perhaps a personal one; why would you prefer thiocyanate?
I do not think the bleaching was insufficient. It was essentially complete, and this was easily verified visually since bleaching was done under normal light. Additionally, dichromate bleach is always very fast and effective in my experience.
In the image shown, I turned on the room lights after the stop bath and kept them on for processing. Note that my room lights are very bright indeed and exposure to them will fully expose any film, no matter what speed, within a second or so. In a subsequent experiment I reduced the exposure by a controlled one-second exposure to my room light. The effect was identical. This suggests that the fogging exposure was complete in both instances.
Yes, I would prefer a chemical fogging step as well. Sadly, I do not have any tin chloride on hand. I might give it a try with sepia toner, but this of course modifies the image tone and adds some density as well on top of the silver image alone.
As to your question on the equipment: it looks like a grafmatic 4x5" film holder. I have never used them, but as far as I understand, it is basically a standard 4x5" film holder with a little number dial that can be used to identify individual holders by exposing a number on each film sheet. I know that one or more people on this forums use these holders. I don't know in which cameras they may or may not fit. I mostly use Lisco Regal film holders.
Hello my dear friend. God bless you .
Happy Easter Holiday .
First, there are many experiments that have proven that potassium thiocyanate works with better accuracy than sodium thiosulfate. Experience (the worksheet I attached before that pertains to the process, Agfa Scala indicates this).
Second - bleaching is strong, but inaccurate. For this, speed does not necessarily mean accuracy, you should increase the time a little, perhaps an additional minute (trust me), or use potassium permanganate because it is very accurate in dealing with all the nanoparticles.
Third - If you want to get a transparent sepia of dark brown, then you will not need to use (re-exposure solution) nor will you need to use the second developer.
You will only need to use ammonia solution.
It consists of:
Deionized water
150 g ammonium chloride
200 ml ammonium hydroxide solution 20%
Water up to 1 liter - used as follows.
Initial wash with lukewarm water
The first developer
Stop Bath
Quick wash
Bleach
Quick wash
Cleaning Bath
Quick wash
Ammonia solution three minutes bath with rapid and violent stirring
wash
wash
Fix
Final wash. Staples
Dealing with an ammonia solution will require wearing a mask mask and safety glasses - working near the ventilator hood. It is a very stupid and evil solution.
Finally, I think working in total darkness is a good thing.
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I brought a data sheet ,, a seller from Ukraine sent me and told me that this type of industrial X-ray film is good quality ..
Could you please take a look and tell me what you think is this paper please.
God bless you i
Re: Use of X-ray film: technical discussion with example images
Quote:
Originally Posted by
mohmadkhatab
Your link is malformed; it should start with "http://" but it starts with "ttp://". In any case, I was able to look at the datasheet & it doesn't provide a lot of useful information. The film is medium speed but that doesn't translate directly to an ISO/ASA film speed; as noted elsewhere in this forum you'll need to do film speed tests yourself to determine the film speed. And remember that x-ray film speed changes under different lighting conditions due to its narrow spectral sensitivity.
The only other noteworthy data are that it is high contrast (most or all x-ray film is) and fine-grained, and that it comes in a variety of sizes.
Regarding the film holders, you're better off (for now, at least) with a standard film holder sized appropriately for your camera or reducing back. You'll find Regal, Lisco, Fidelity Deluxe, Riteway, Eastman Kodak, and Toyo are all readily available. I prefer the Toyo holders as they are very precisely manufactured and they weigh less than some of the older holders, but any of these will work.
Here is a discussion of film holders from this forum.
Since you'll probably be cutting down larger film to fit your holders, remember that the nominal size is a bit larger than the actual film size needed to fit. For instance, 4″×5″ film is actually closer to 3⅞″×4⅞″. I put white tape on my paper cutter to act as a guide when I'm trimming x-ray film.
Re: Use of X-ray film: technical discussion with example images
Quote:
Originally Posted by
seezee
Your link is malformed; it should start with "http://" but it starts with "ttp://". In any case, I was able to look at the datasheet & it doesn't provide a lot of useful information. The film is medium speed but that doesn't translate directly to an ISO/ASA film speed; as noted elsewhere in this forum you'll need to do film speed tests yourself to determine the film speed. And remember that x-ray film speed changes under different lighting conditions due to its narrow spectral sensitivity.
The only other noteworthy data are that it is high contrast (most or all x-ray film is) and fine-grained, and that it comes in a variety of sizes.
Regarding the film holders, you're better off (for now, at least) with a standard film holder sized appropriately for your camera or reducing back. You'll find Regal, Lisco, Fidelity Deluxe, Riteway, Eastman Kodak, and Toyo are all readily available. I prefer the Toyo holders as they are very precisely manufactured and they weigh less than some of the older holders, but any of these will work.
Here is a discussion of film holders from this forum.
Since you'll probably be cutting down larger film to fit your holders, remember that the nominal size is a bit larger than the actual film size needed to fit. For instance, 4″×5″ film is actually closer to 3⅞″×4⅞″. I put white tape on my paper cutter to act as a guide when I'm trimming x-ray film.
God bless you, my dear teacher.
You are a very nice man.
Greetings to all of you, all respected Oklahoma City metro.
I benefited greatly from your wonderful response.
Regarding the movie stand.
This piece was given to me by an Egyptian doctor who bought it from America a long time ago and does not want it, he had known that I was looking to buy a large camera, and for this he wanted to give it to me and says that this piece can carry up to eight slides at once and switch between them after Every picture.
I actually don't really know, and I'm still looking for a cheap camera and it's complicated in light of the emergency imposed in the country.
God bless you
Greetings to you, dear sir.
Re: Use of X-ray film: technical discussion with example images
I checked the datasheet of the foma xray film. It seems to be intended for direct exposure with xrays, not with visible light. The emulsion is likely still sensitive to at least blue light and perhaps green, but some testing would be required to figure out if and how it can be used for photography. Frankly, I'd skip this film and choose a film stock that is known to work with normal light.
Re: Use of X-ray film: technical discussion with example images
Quote:
Originally Posted by
mohmadkhatab
Third - If you want to get a transparent sepia of dark brown, then you will not need to use (re-exposure solution) nor will you need to use the second developer.
You will only need to use ammonia solution.
It consists of:
Deionized water
150 g ammonium chloride
200 ml ammonium hydroxide solution 20%
Water up to 1 liter - used as follows.
Initial wash with lukewarm water
Mohmad, thanks for sharing. I'm curious to know from where did you get this formula. And have you used it?
Re: Use of X-ray film: technical discussion with example images
Quote:
Originally Posted by
koraks
I checked the datasheet of the foma xray film. It seems to be intended for direct exposure with xrays, not with visible light. The emulsion is likely still sensitive to at least blue light and perhaps green, but some testing would be required to figure out if and how it can be used for photography. Frankly, I'd skip this film and choose a film stock that is known to work with normal light.
I have experimented with several "x-ray only" films and have not found one I could not use in cameras.
Re: Use of X-ray film: technical discussion with example images
I got it from my Austrian friend, Mr. Rudi.
Mr. Rudi, today he went to his father's funeral, Professor at the Faculty of Agriculture and he was a great man.
I really did try that recipe and came up with somewhat acceptable results, but the movie was expired and the first developer didn't get the job done best. Unfortunately, the first developer was weak, at that time I used the first process developer (AP41), which was then the developer I had today.
- But it was preliminary results indicating that the formula as a whole is correct, but the first developer must be very strong and very effective more than we thought.
- I will repeat those tests again, but I am waiting for fresh black and white films that will come to me from Ukraine soon,
Re: Use of X-ray film: technical discussion with example images
This is an important and optimistic narration.
Re: Use of X-ray film: technical discussion with example images
Quote:
Originally Posted by
Jim Noel
I have experimented with several "x-ray only" films and have not found one I could not use in cameras.
How do the 'xray only' films relate to the 'regular xray' films in your experience? Comparable, or slower + higher contrast?
