Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,205   Posts: 1,531,659   Online: 1146
      
Page 1 of 3 123 LastLast
Results 1 to 10 of 22
  1. #1

    Join Date
    Oct 2008
    Location
    Desert of Arizona
    Shooter
    35mm
    Posts
    16

    Let me see if I got this right; Pinhole photography first try.

    I just ordered a holga 120WPC that has a f/135 hole (should have it by Friday); if I use Ilford HP5 plus (400) film and set my lightmeter to read the film iso at 100 and use a exposure reading for f64, I should get my exposure right; correct??
    The main thing is to keep the main thing the main thing.

  2. #2
    Lee L's Avatar
    Join Date
    Nov 2004
    Shooter
    Multi Format
    Posts
    3,244
    Close enough for Holga (and most other work). That's about 2.15 stops difference.

  3. #3
    RalphLambrecht's Avatar
    Join Date
    Sep 2003
    Location
    the villages .centralflorida,USA and Germany
    Shooter
    Multi Format
    Posts
    6,433
    Images
    1
    Close enough, but don't forget the reciprocity failure with long exposure times!
    Attached Thumbnails Attached Thumbnails Reciprocity.jpg  
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  4. #4
    Lee L's Avatar
    Join Date
    Nov 2004
    Shooter
    Multi Format
    Posts
    3,244
    Here's an earlier post with reciprocity corrected times that include HP5+. The chart is based on data from Howard Bond's extensive testing in an article in Phototechniques magazine, 2003. Metered times are in seconds, adjusted times are in mm:ss format. Data went to 240 seconds. Adjustment from metered times longer than that are extrapolated from the data.

    http://www.apug.org/forums/attachmen...0&d=1238435346

    Lee

  5. #5
    RalphLambrecht's Avatar
    Join Date
    Sep 2003
    Location
    the villages .centralflorida,USA and Germany
    Shooter
    Multi Format
    Posts
    6,433
    Images
    1
    jonpaul

    Let us know which one worked better for you!
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  6. #6

    Join Date
    Oct 2008
    Location
    Desert of Arizona
    Shooter
    35mm
    Posts
    16
    Thanks for the info; I'll let you all know how it works out. Again, thanks. - -Jonpaul
    The main thing is to keep the main thing the main thing.

  7. #7

    Join Date
    Apr 2004
    Location
    Montgomery, Il/USA
    Shooter
    Multi Format
    Posts
    5,026
    Apparently Acros 100 doesn't present the same problems with reciprocity failure and since you're in AZ you should be able to use the slower film with no problem.
    Heavily sedated for your protection.

  8. #8
    Lee L's Avatar
    Join Date
    Nov 2004
    Shooter
    Multi Format
    Posts
    3,244
    If he's using HP5+ at ISO 400 in daylight at f:135, he's going to get exposure times between about 1/10 sec and 1.5 seconds, so his main problem won't be reciprocity, or trying to shorten exposure times. It could be finding a good way to accurately time exposures that short.

    Lee
    Last edited by Lee L; 08-10-2010 at 07:59 PM. Click to view previous post history.

  9. #9

    Join Date
    Oct 2008
    Location
    Desert of Arizona
    Shooter
    35mm
    Posts
    16
    Holga 120WPC pinhole camera results: Before going out I was careful to load Ilford HP5+ and used gaffers tape along the back cover seams and frame counter window to keep light leakage at a minimum, and used a Minolta IVF incident light meter to take readings. I took six 6x12 exposures: #1-set meter at iso 100 @ f64 meter, indicated 1-second, shot @ 1-second. #2-meter set as before indicated 1-second, shot @ 1.3 second (adjusting for reciprocity using table provided by Ralph Lambrecht). #3-set meter at iso 400 @ f22 and used Pinhole Designer software table, indicated 20th second, shot at 4-seconds. #4,5,6,-set meter iso to 100 using f64, indicated 1.5-seconds, shot at 2-seconds. Timing of the exposures was done in the primitive one-one-thousand manner. I processed the film using Ilford Ilfotec DDX developer 1+4 dilution at 68F for 9-minutes. All the exposures were usable, but,the best exposure was #2, using the reciprocity table. Thanks Ralph Lambrecht.
    The main thing is to keep the main thing the main thing.

  10. #10
    RalphLambrecht's Avatar
    Join Date
    Sep 2003
    Location
    the villages .centralflorida,USA and Germany
    Shooter
    Multi Format
    Posts
    6,433
    Images
    1
    I'm glad to hear that it worked for you. Many thanks for the feedback!
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

Page 1 of 3 123 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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