Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,972   Posts: 1,558,696   Online: 822
      
Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 40
  1. #11

    Join Date
    Dec 2002
    Shooter
    Large Format
    Posts
    6,242
    While the effective contrast does not alter with enlargement size, the visual effect is one of a decrease in contrast as the print size is increased. This has been recognized and reported by a number of noted photographers over the years. The reason is that as print size increases the tonal information is spread further apart and the visual effect is one of a decrease in contrast.

    However, if one is consistantly using high contrast filtration to achieve the desired print contrast then the negative simply has not been developed to the desired density range to match the exposure scale of the paper.

  2. #12

    Join Date
    Nov 2002
    Location
    Melbourne, Australia
    Shooter
    Medium Format
    Posts
    995
    A safelight that's not safe enough can cause dull prints. Multigrade papers are sensitive to a wider spectrum than the graded papers, and it wouldn't surprise me to find some old style safelights in college darkrooms. The Kodak web site has a pdf about safelight testing. It might seem too involved, but at least the first test is very much worth doing. The basic point is to expose the test sheet to a light grey first, and then do the coin test. Or try printing without the safelight at all, if you can, to compare. There should be no difference.

    One thing I resort to when I lose my bearings (is it the film, my lighthead,...?) is to use a sheet of graded paper (probably grade 3 for 35mm) to narrow down the possibilities.

  3. #13
    Bob Carnie's Avatar
    Join Date
    Apr 2004
    Location
    Toronto-Ontario
    Shooter
    Med. Format RF
    Posts
    4,676
    Images
    14
    Bruce
    I would tend to agree with Marks statement, how much the contrast decreases is debatable, but I have noticed a slight loss of visual contrast with enlargement.
    I do not think that this is the answer to the original post though.

  4. #14

    Join Date
    Mar 2005
    Shooter
    35mm
    Posts
    40
    I am only enlarging to 8X10. Negs look good. I am thinking it might be that enlarger.

    One of the questions though, does developer have any effect on contrast? I'm not really talking about strength, but brand. I know that sprint chemistry is one of the cheapest on the market.

    The safelight idea is interesting also. When my darkroom is up and running, I will probably answer that question. By the way, I am using the darkroom because I am an instructor there, so its free to me. Not photography, but welding and metallurgy

  5. #15

    Join Date
    Nov 2004
    Shooter
    Multi Format
    Posts
    2,056
    Kevin, try a safelight test. Take a small piece of photo paper (size of a wallet photo will do) and put a coin on it for 15 min. Process that piece of paper and if there is the ouline of the coin, the safelight is no good. A bad safelight will give you a bad case of the grays.

  6. #16
    SuzanneR's Avatar
    Join Date
    Sep 2004
    Location
    Massachusetts
    Shooter
    Multi Format
    Posts
    5,740
    Images
    139
    I recently tried the Sprint print developer with Ilford MGIV, and found the results about the same as using dektol. FWIW, I think the differences between print developers are far more subtle than differences between film developers. How long did you keep it in the developer? For awhile I was only developing for two minutes, but recently, I've been developing for three minutes, and I get much richer blacks.

    Hope that helps a little!

  7. #17

    Join Date
    Nov 2004
    Shooter
    Multi Format
    Posts
    2,056
    I hope you followed that; put the coin on the paper with the room lights off and the safelights ON.

  8. #18
    Will S's Avatar
    Join Date
    Nov 2004
    Location
    Madison, Wisconsin
    Shooter
    Multi Format
    Posts
    698
    Images
    34
    This article has a really interesting way to test the safelight(s). It argues that you need to expose the paper before the test in order to increase its sensitivity, as paper that has some exposure already is more sensitive to the safelight than paper with no exposure.

    Check it out:

    http://www.jobo-usa.com/faq/safelight_testing.htm
    "I am an anarchist." - HCB
    "I wanna be anarchist." - JR

  9. #19
    Bob Carnie's Avatar
    Join Date
    Apr 2004
    Location
    Toronto-Ontario
    Shooter
    Med. Format RF
    Posts
    4,676
    Images
    14
    Thanks Will

    this is why I like this site so much, a quick link and a practical tool for the darkroom .

  10. #20
    Bruce Osgood's Avatar
    Join Date
    Sep 2002
    Location
    Brooklyn, N.Y. USA
    Shooter
    Multi Format
    Posts
    2,450
    Images
    47
    Quote Originally Posted by Bob Carnie
    Bruce
    I would tend to agree with Marks statement, how much the contrast decreases is debatable, but I have noticed a slight loss of visual contrast with enlargement.
    I do not think that this is the answer to the original post though.
    I agree in that this is not Kevins problem, nor is a leaky enlarger the problem (I do suppose an enlarger could leak different amounts of light at different elevations). But a filter is a filter is a filter. A grade of filtration does not change its grade due to weakness of light being transmitted. I'd bet you a dime to a donut the original exposure was not what it was thought it to be. Or the enlarging calculations were off. Could even be the enlarging lens iris may be off. Maybe a given lens' f-11 isn't REALLY 2 stops less light as 5.6?

Page 2 of 4 FirstFirst 1234 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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