Page 551 of 559 FirstFirst ... 51451501541549550551552553 ... LastLast
Results 5,501 to 5,510 of 5589

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

  1. #5501

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

    Quote Originally Posted by Philippe Grunchec View Post
    Why don't you mix your own D-23?

    I have a lot of formula,
    There is nothing wrong, (D23) is available and very inexpensive, but I do not see it as distinct at all. It is a very basic and ordinary formula. What do you like about that poor formula?
    I love the formula (AGFA14) it is very soft and very gentle, and when I flip over violently, I get good contrast with unparalleled smoothness.
    - But it is okay, I will listen to your advice, I do not reject expert advice no matter how objectionable,
    I will listen to you and implement what you say, there is no problem.
    But in reality, I have a very important question ,,
    - Has anyone experimented with reversing the negative image to obtain positive transparency from X-ray films?
    I hope to get an answer to this important question.
    God bless you
    Another somewhat trivial question:
    - My friend has a wooden (5x7) camera.
    There is a radiographer who wants to sell him (63) Sheet (10x12) cm. The question is ,, Can this measurement succeed in working on that camera?

  2. #5502

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

    Quote Originally Posted by dpaqu View Post
    Is EKTASCAN B/RA gone? Are there any other single sided x-ray emulsions?
    http://www.astrum-ltd.com/ru/rentgenovskie-plenki.html

  3. #5503

    Join Date
    Jun 2014
    Posts
    1,719

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

    Quote Originally Posted by mohmadkhatab View Post
    [B]
    - Has anyone experimented with reversing the negative image to obtain positive transparency from X-ray films?
    Haven't tried it I think, but it should work just like with any other film.

    - My friend has a wooden (5x7) camera.
    There is a radiographer who wants to sell him (63) Sheet (10x12) cm. The question is ,, Can this measurement succeed in working on that camera?
    He'll need a reducing back for his camera and appropriate film holders. With a bit of luck, the film will fit in 4x5" holders and a 4x5" reducing back can be used, but it depends on the exact dimensions of the film. Also, getting hold of a reducing back for the camera may be challenging. It's probably easier to get some larger format film and cut it down to 5x7". But of course that depends on the availability of film where your friend lives.

  4. #5504
    Corran's Avatar
    Join Date
    Apr 2011
    Location
    North GA Mountains
    Posts
    7,565

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

    A long time ago I played around with enlarging 35mm negatives onto x-ray film, to make an internegative (positive). Then I would contact print that onto another sheet to make the negative. Intention was larger negatives for contact printing (alt processes).

    I was using double-sided film which hopelessly blurred the image after the two intermediaries. I didn't have enough success to bother fine-tuning exposure/development/density tests. And, as a positive medium, the x-ray film's blue base was unappealing.

    Perhaps better results would be obtainable with single-sided, but either way I didn't try anything more. But it's cheap, so try it out if you want.
    Bryan | Blog | YouTube | Instagram
    All comments and thoughtful critique welcome

  5. #5505

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

    [QUOTE=koraks;1545866]Haven't tried it I think, but it should work just like with any other film.

    God bless you, my friend ,,
    Thank you very much ,,
    But in your opinion, what is the available x-ray film size that fits the (5x7) camera? From your point of view?
    And will this camera accept that this 4x5 film stand be installed assuming that we will find it individually one way or another depending on luck or the like?
    - Regarding my question about converting the X-ray film to positive transparency, I mean that is done directly.
    I do not mean to reprint an image from (35mm) film to an x-ray film in order to have positive transparency.
    No, that's not what I meant.
    I have been using AGFAscala since the beginning of the X-ray film development.
    The file is well known and known to everyone and I think that most professors and experts in this forum know it and they have inevitably gone through that experience before (35mm) or (120mm) films, but I wanted to think about the idea that this process be applied to X-ray films, , why not ?
    - The file with attachments, and of course the photographic researcher designed this process on the basis of identification with the original process (AGFAscala)osbahr_reversal.pdf, but with great regret, he erred in that he designed everything on the basis that it is intended to work on a machine (JOBO) only, and with a capacity (260 ml) Only ml.
    Therefore, if you want to prepare one liter, you will fall into the trap of complicated calculations that I failed to calculate, because if you prepare 4 packages, each one is a capacity of (260 ml), and you add them in one container, then the result will become an increase in the concentrations of chemical elements by 300% of the original process design, so I am very confused in this regard.
    Last edited by mohmadkhatab; 8-Apr-2020 at 09:03.

  6. #5506

    Join Date
    Jan 2012
    Location
    Beijing
    Posts
    209

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

    The problem I see with doing reversal is that the film base is not clear, its blue. So if the goal is to show the positive as the final image, it's not a B&W picture, but a mostly blue picture.

    What is the end goal of the positive?

  7. #5507

    Join Date
    Dec 2018
    Posts
    228

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

    I'm just putting this here for reference purposes...
    B/W reversal process for many film sizes, including 5x7.

    dr5.us

  8. #5508

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

    Quote Originally Posted by blue4130 View Post
    The problem I see with doing reversal is that the film base is not clear, its blue. So if the goal is to show the positive as the final image, it's not a B&W picture, but a mostly blue picture.

    What is the end goal of the positive?
    What is the problem in blue?
    The blue color is a very beautiful color - I don't see any objection to the blue color dominating the scene - why not?
    It is basically a mono image - whatever color it dominates.
    Of course, the black color with its grayscale is really comfortable for the eye and very logical, but I do not mind if the image is covered in blue and its gradations or sepia - I have no problem.
    What is the purpose of obtaining a positive image?
    I will answer the question with a question.
    - What is the goal of obtaining a negative image?
    - I can encapsulate the positive big size film (8x10), put it in a frame and hang it on the wall directly, without the need to print the picture .....................
    - Perhaps we can manufacture a camera that can film a huge x-ray film measuring (30x40) cm. We will put it inside a frame and hang it on the wall directly or sell the frame and the film inside - without going into another war with the magnifier and printing.
    These are just crazy ideas that complement the main crazy idea, which is the idea of ​​photographing on x-ray films.

    My last question: Have you ever tried and tested this strange idea?

  9. #5509
    Corran's Avatar
    Join Date
    Apr 2011
    Location
    North GA Mountains
    Posts
    7,565

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

    See my previous posts regarding positive internegative.

    Blue is fine, but I don't think it looks good as a positive "finished" medium for a grey scale image. Highlights are blue, shadows are blackish-blue. You can do what you want, of course.

    This isn't a new idea. Search in the thread and you'll find it comes up occasionally, because of course it sounds fun and easy...

    By all means, enlarge whatever negative size you want on to as large a sheet of x-ray film as you can. No harm in trying, keep the film manufacturers in business. I may be buying some 14x17 x-ray soon...
    Bryan | Blog | YouTube | Instagram
    All comments and thoughtful critique welcome

  10. #5510

    Join Date
    Jun 2014
    Posts
    1,719

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

    [QUOTE=mohmadkhatab;1545883]
    Quote Originally Posted by koraks View Post
    Haven't tried it I think, but it should work just like with any other film.
    But in your opinion, what is the available x-ray film size that fits the (5x7) camera? From your point of view?
    I don't think 5x7" xray film is available, but you can get 18x24cm or 8x10" film and cut it down to fit 5x7" holders. Of course there will be some waste.

    And will this camera accept that this 4x5 film stand be installed assuming that we will find it individually one way or another depending on luck or the like?
    That depends on the camera. You may need to modify the camera and/or the reducing back in order to make things fit. Also, a reducing back generally adds a bit to the distance between the lens and the film, which means there can be problems with focus and movements when short lenses (90mm and shorter) are used. With longer lenses it's usually not a problem. But again, it depends on the specific equipment involved.

    - Regarding my question about converting the X-ray film to positive transparency, I mean that is done directly.
    Yes, that can be done, just as with any other type of B&W film. You'll have to figure out the processing chemistry and parameters yourself, but that's just a matter of systematic testing, with which I think you are already familiar.

    - The file with attachments, and of course the photographic researcher designed this process on the basis of identification with the original process (AGFAscala)osbahr_reversal.pdf, but with great regret, he erred in that he designed everything on the basis that it is intended to work on a machine (JOBO) only, and with a capacity (260 ml) Only ml.
    Therefore, if you want to prepare one liter, you will fall into the trap of complicated calculations that I failed to calculate, because if you prepare 4 packages, each one is a capacity of (260 ml), and you add them in one container, then the result will become an increase in the concentrations of chemical elements by 300% of the original process design, so I am very confused in this regard.[/B]
    Converting to roughly 1 liter doesn't have to be complicated. Just multiply everything in the pdf by 4. This way you end up with 1040ml, which is close enough to 1 liter for any application. If you need exactly 1000ml, just discard the excess 40ml.

Similar Threads

  1. Technical Pan Film
    By Jehu in forum Darkroom: Film, Processing & Printing
    Replies: 34
    Last Post: 22-Apr-2016, 18:42
  2. Images, not technical discussions.
    By rdenney in forum Image Sharing (Everything Else) & Discussion
    Replies: 0
    Last Post: 23-Jul-2015, 14:16
  3. Replies: 91
    Last Post: 23-Jul-2015, 12:01
  4. T Max 400 Technical Discussion by Sandy King
    By Michael Kadillak in forum Darkroom: Film, Processing & Printing
    Replies: 38
    Last Post: 7-Feb-2006, 06:08
  5. Discussion: Pyro stain, silver rich film & thick emulsion
    By Pete Caluori in forum Darkroom: Film, Processing & Printing
    Replies: 10
    Last Post: 22-Nov-2003, 04:39

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •