Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,518   Posts: 1,543,761   Online: 858
      
Page 3 of 3 FirstFirst 123
Results 21 to 25 of 25
  1. #21
    Sirius Glass's Avatar
    Join Date
    Jan 2007
    Location
    Southern California
    Shooter
    Multi Format
    Posts
    13,118
    Quote Originally Posted by Bruce Osgood View Post
    When enlarging from 8X10 to 11X14 there is an ever-so slight reduction in contrast. I thought there was a problem with the math but the math is correct.

    I'm not too concerned with this mystery as the results are generally quite pleasing.
    That is because the physics of light is linear [predictable], while the chemistry of photography is non-linear [not totally predictable].

    Steve
    Warning!! Handling a Hasselblad can be harmful to your financial well being!

    Nothing beats a great piece of glass!

    I leave the digital work for the urologists and proctologists.

  2. #22
    brian steinberger's Avatar
    Join Date
    Jan 2007
    Location
    Pennsylvania
    Shooter
    Med. Format RF
    Posts
    2,331
    Blog Entries
    1
    Images
    100
    This evening I re-printed a photograph at a larger size. The previous print was 7x7" on 8x10 Ilford MGIV FB glossy. The exposure was for 9.5 sec. at f/16 at grade 3 1/2.

    Tonight I printed the image up to 10x10" on 11x14 Ilford MGIV FB glossy. I had read this thread previously and instead of doubling the exposure, I just opened the lens up one stop (essentially the same thing). After a few test strips my final exposure was at 9.5 sec. at f/11 at grade 3 1/2... exactly one stop more exposure than the smaller print. Its funny how simple things are sometimes. But then I thought about it, the 7x7" print has 42 inches of area, and the 10x10" has 100 inches of area.. Approx. double.

    I just wanted to add this for anyone, because this was an eye opener for me and will certainly give me a great starting point when re-printing from 8x10 to 11x14 (on MGIV anyway). No calculations or densitometer needed.

  3. #23
    Vincent Brady's Avatar
    Join Date
    Mar 2008
    Location
    Co. Kildare - Ireland
    Shooter
    35mm
    Posts
    2,001
    Images
    168
    Spoilsport Brian, you know how we love our secret ways and calculations.

    -TEX

  4. #24
    ic-racer's Avatar
    Join Date
    Feb 2007
    Location
    Midwest USA
    Shooter
    Multi Format
    Posts
    6,217
    Just curious, why do we have three page thread here when there is a "sticky" thread on the same topic?

  5. #25

    Join Date
    Sep 2002
    Location
    Willamette Valley, Oregon
    Shooter
    Medium Format
    Posts
    3,684
    Quote Originally Posted by brian steinberger View Post

    But then I thought about it, the 7x7" print has 42 inches of area,
    and the 10x10" has 100 inches of area.. Approx. double.
    Although the larger print is close to 140% larger you found
    that a 100% increase in exposure gave same results. How
    do you account for that? In my experience that difference
    of 40% is easily discernable. Dan

Page 3 of 3 FirstFirst 123


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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