Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,700   Posts: 1,549,213   Online: 1179
      
Page 1 of 2 12 LastLast
Results 1 to 10 of 12
  1. #1
    Andrew O'Neill's Avatar
    Join Date
    Jan 2004
    Location
    Coquitlam, BC, Canada
    Posts
    618

    X-Ray Film Reciprocity Effect

    Incase anyone who uses x-ray film particularly CSX green latitude, here are some curves showing the effect of long exposures.

    The 1/8th sec curve represents normal. Some development compensation will most likely be needed as well, starting at the 10 second mark.
    Attached Thumbnails Attached Thumbnails Xray-Reciprocity-Graph1.jpg  
    Last edited by Andrew O'Neill; 05-17-2010 at 08:58 PM. Click to view previous post history.

  2. #2
    Andrew O'Neill's Avatar
    Join Date
    Jan 2004
    Location
    Coquitlam, BC, Canada
    Posts
    618
    Exposures were made under an enlarger with a 31 step stouffer wedge. Film developed in Rodinol 1+50 in a tray.

  3. #3
    Vaughn's Avatar
    Join Date
    Dec 2006
    Location
    Humboldt Co.
    Shooter
    8x10 Format
    Posts
    4,677
    Images
    40
    Nice curves, but how does the rate of failure relate to conventional films and TMax films? Just so that I can wrap my poor brain arounf it!

    Vaughn
    At least with LF landscape, a bad day of photography can still be a good day of exercise.

  4. #4
    Andrew O'Neill's Avatar
    Join Date
    Jan 2004
    Location
    Coquitlam, BC, Canada
    Posts
    618
    Compared to X-Ray film:

    HP5+: 1s give 1/3rd stop more; 10s give 1.5x; 100s give 4x more exposure
    No development compensation required.


    TMY-2: 1s no compensation; 10s give 1.2x (1/3rd stop); 100s 4x more.
    No development compensation required.

  5. #5
    Andrew O'Neill's Avatar
    Join Date
    Jan 2004
    Location
    Coquitlam, BC, Canada
    Posts
    618
    Here is a rough tonal/colour sensitivity comparison between X-ray and TMY-2.
    Green does appear slightly lighter and darker for yellow and beyond.
    Tonally, TMY-2 is much much nicer. With the use of filters (#58 green filter for example) one could pretty much get it to look like the x-ray films colour response. Just with much nicer tonalities and sharpness.
    I do not have a film scanner, so please excuse the poor quality.
    Attached Thumbnails Attached Thumbnails Comparison.jpg  

  6. #6
    Andrew O'Neill's Avatar
    Join Date
    Jan 2004
    Location
    Coquitlam, BC, Canada
    Posts
    618
    After playing around with this film some more, it will not become my main film. I'll stick with HP5 and Timmy-2. I like smooth tonalities, sharpness, decent reciprocity characteristics, and a film that won't scratch so easily.

  7. #7
    Andrew O'Neill's Avatar
    Join Date
    Jan 2004
    Location
    Coquitlam, BC, Canada
    Posts
    618
    Four years later, and I'm still using x-ray film both double-side green and single-sided blue. If you are careful, you can avoid scratches, even with flat-bottomed trays (which I prefer to use). Not my main film, but nice to have in certain situations.

    This was exposed on double-sided green latitude, unstripped. I prefer not to as a stripped neg's tones are mushy. Yes, the stripped neg is a tad sharper, but grain is more noticeable. To my eye, unstripped looks great and you only notice the softness in side-by-side comparisons. All of this is my opinion, of course!
    Attached Thumbnails Attached Thumbnails MIssionAbbey.jpg  

  8. #8
    BetterSense's Avatar
    Join Date
    Aug 2008
    Location
    North Carolina
    Shooter
    35mm
    Posts
    2,872
    Under incandescent lighting, with exposures of 5-30 seconds, I found Green Latitude to be significantly faster than Foma 100. Like several stops faster. Foma 100 has legendarily bad reciprocity failure, but I find it interesting that even Xray film is better!
    f/22 and be there.

  9. #9
    Toffle's Avatar
    Join Date
    Mar 2007
    Location
    Point Pelee, ON, Canada
    Shooter
    Multi Format
    Posts
    1,796
    Images
    122
    Thanks for this, Andrew. I've been cutting Fuji HR-T Green 8x10 down to 4x5 for the last year or so with some really good results. It's good to have some clue about reciprocity performance on really long exposures. It seems to go very well with my pinhole work, but I've had a couple of longer exposures that fell off the chart, so to speak. On the other end of the scale, I've had difficulty with exposures under bright blue skies. I generally get good results at ISO 50, but under high UV situations, it appears much faster. Do you have any insights into the characteristics of this film?

    Cheers,
    Tom
    Tom, on Point Pelee, Canada

    Ansel Adams had the Zone System... I'm working on the points system. First I points it here, and then I points it there...

    http://tom-overton-images.weebly.com


  10. #10

    Join Date
    May 2013
    Location
    US
    Shooter
    Large Format
    Posts
    2,060
    Thread marked. Thank you for your work.

Page 1 of 2 12 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin