Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,537   Posts: 1,544,262   Online: 775
      
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 23

Thread: Printing Times

  1. #11

    Join Date
    Nov 2004
    Location
    The highest state
    Shooter
    Multi Format
    Posts
    1,916
    Just set up my 45MX, Aristo cold light. My exposure times at 10 x 10 from 120 negs are waaaay too short, 2-4 seconds on a good neg, F/8 on my Apo Rodenstock 90 F/4. The distance on my upper bellows is about 2.5 inches. Paper is Multigrade RC.

    What gives?

  2. #12
    CPorter's Avatar
    Join Date
    Feb 2004
    Location
    West KY
    Shooter
    4x5 Format
    Posts
    1,662
    Images
    24
    Quote Originally Posted by PKM-25 View Post
    Just set up my 45MX, Aristo cold light. My exposure times at 10 x 10 from 120 negs are waaaay too short, 2-4 seconds on a good neg, F/8 on my Apo Rodenstock 90 F/4. The distance on my upper bellows is about 2.5 inches. Paper is Multigrade RC.

    What gives?

    Underexposed thin negatives.

  3. #13

    Join Date
    Nov 2004
    Location
    The highest state
    Shooter
    Multi Format
    Posts
    1,916
    Quote Originally Posted by CPorter View Post
    Underexposed thin negatives.
    Nope, good negs.

  4. #14
    eddie's Avatar
    Join Date
    Jul 2005
    Location
    Northern Virginia
    Shooter
    Multi Format
    Posts
    1,419
    Images
    214
    If you're using a cold light head, the upper bellows shouldn't be extended at all. 2.5 inches seems too high (mine flattens to about 1 inch). The head should be as close to the negative carrier as possible. I don't know if this is having any effect on your exposure times, but the upper bellows is used to move the condensers, which (obviously) you're not using.
    It sounds like you're using the format gauge (the little red arrow) on the right side of the upper bellows, and setting it for 2 1/4.It seems to me as if you're not set up properly.
    Last edited by eddie; 02-05-2012 at 12:44 PM. Click to view previous post history. Reason: clarity

  5. #15
    CPorter's Avatar
    Join Date
    Feb 2004
    Location
    West KY
    Shooter
    4x5 Format
    Posts
    1,662
    Images
    24
    Quote Originally Posted by PKM-25 View Post
    Nope, good negs.
    ok, a good negative------but you've stopped down 2 stops from f/4 to f/8, and having to use a 2-4 sec exposing time, for the desired high value I presume? Wrong Aristo lamp, too much wattage, IDK. I guess so, what does give.......if you say that the negative is good.

  6. #16

    Join Date
    Feb 2009
    Shooter
    Large Format
    Posts
    662
    There’s nothing magical going on. Whatever light intensity illuminates the negative, the light that passed through the negative now passes through the lens at the stated f/8 resulting in 2-4 second exposures on the paper you’re using.

    Most of us find that faster than we’d expect at the approximately 4.7X needed to make a 10” x 10” print of a 6 x 6cm negative at f/8 (assumed cropping from an approximately 10 ¼” x 10 ¼” projection).

    Assuming that the lens aperture is correctly closing to the stated f/8, then the likely explanation is: brighter than usual light source, thinner than usual negative, or a combination of these.

    You didn’t specify what filters you’re using. Obviously an unfiltered exposure is shorter than a filtered exposure—possibly much shorter.

    Regarding #14, the closer the light source to the negative the brighter the projection and the shorter the printing time. Placing the source farther from the negative would result in longer printing time.

    Thus, one way to increase the printing time is to open the upper bellows to move the light source farther from the negative. This will work so long as the negative remains evenly illuminated.
    Last edited by Ian C; 02-05-2012 at 01:22 PM. Click to view previous post history.

  7. #17
    eddie's Avatar
    Join Date
    Jul 2005
    Location
    Northern Virginia
    Shooter
    Multi Format
    Posts
    1,419
    Images
    214
    Quote Originally Posted by Ian C View Post
    Regarding #14, the closer the light source to the negative the brighter the projection and the shorter the printing time. Placing the source farther from the negative would result in longer printing time.
    The distance issue doesn't make much sense to me either. You'd think the exposure would get longer...
    Another question. Is the diffusion disc installed on the head?

  8. #18

    Join Date
    Feb 2005
    Location
    Richmond, VA
    Shooter
    Multi Format
    Posts
    1,066
    Looks like this thread ran out a few days ago, but - one other question: Which lamp is in the housing? I think someone mentioned this before. My first Aristo head (early 80's) came with the HI(high intensity) lamp, which was always too bright for much of my work, regardless of format. I bought the Aristo (voltage?) reducing unit and solved the problem, just dialed in a lower setting and adjusted the output.

  9. #19

    Join Date
    Apr 2010
    Location
    Jersey Channel Islands
    Shooter
    Medium Format
    Posts
    333
    Whatever the negative needs, although I prefer to stop well down and have a longer print exposure if I have a lot of dodging to do, it gives me more time,and slight errors in dodging/burning do not make such a big difference at a longer exposure.
    Richard

  10. #20
    Roger Cole's Avatar
    Join Date
    Jan 2011
    Location
    Suburbs of Atlanta, GA USA
    Shooter
    Multi Format
    Posts
    3,890
    Quote Originally Posted by Thomas Bertilsson View Post
    Whatever the negative demands.

    My main exposure times are usually between 10 and 40 seconds, and any burning required is in addition to that.
    I draw a stick figure of the print where I note dodging and burning (at varying filter grades), note main exposure time, lens aperture, filtration, etc. This teaches me that it's important to be able to repeat the results down the road, and it helps me remain consistent with my work.

    So, whatever the print seems to demand, I don't care what the actual number is, just that I know exactly what the number is.
    I do something very similar, often less elaborate if the negative doesn't need that much dodging and burning (but if it does, I do pretty much the same.)

    I prefer longer printing times, within reason, to give time for dodging if needed, and the longer burning times with smaller stops/dimmer source also seem to make it easier for me to get a nicely blended undetectable burn. I prefer 15-30 seconds but don't usually open up another stop unless I'm over 40 seconds.

Page 2 of 3 FirstFirst 123 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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