Ahh, liquid emulsion. And some other questions.

Discussion in 'Darkroom Developing and Printing' started by Some Dude, Oct 10, 2003.

  1. Some Dude

    Some Dude Guest

    This stuff is sweeeeeeeeeet.

    Ok I have a potentially stupid question so be forewarned...

    I am going to do some painting of emulsion on canvas and mask off some
    parts of it and then expose it. My question has to do with exposing
    without an enlarger. I sold all my enlargers a few years back but I
    do happen to have a nice old Kodak Slide projector.

    So what i'm thinking is....Use the slide projector to expose the
    emulsion (or even regular rc paper as a test). The slides are scala
    200x and others. This is strictly experimental so there are no output
    "requirements".

    That'll work, right? I'd just have to get my exposure timing down due
    to the immense strength of the projector bulb...eh?





    Cheers,
    -sd
    http://www.zoom.sh
     
    Some Dude, Oct 10, 2003
    #1
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  2. You could rig up an aperture on the slide projector lens to reduce the light
    (and also increase your depth of field). All you'd need would be an opaque
    disk with a hole in the center.

    I wouldn't know where on the lens to put this, though: on front? behind?
    Someone else here more knowledgable about optics could surely tell you that.

    Or maybe you could substitute a dimmer bulb in the projector.


    --
    Call the American Teleservices Association at (317) 816-9336
    and let them know just how much you appreciate their "services".
    Telephone # courtesy of Dave Barry (yes, that Dave Barry).
    (Read all about it on Slashdot:
    http://slashdot.org/articles/03/10/05/1350243.shtml?tid=103&tid=133&tid=158&tid=186&tid=99)
     
    David Nebenzahl, Oct 10, 2003
    #2
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  3. Some Dude

    Some Dude Guest

    Yeah I was thinking the dimmer bulb thing was a good idea. Or a dying
    one or something.. :) The good thing about this projector (well,
    maybe all projectors have this) is that it has different brightness
    settings for the bulb.

    I was also thinking of using (borrowing) one of those display
    projectors (for computers)- those things allow you to change all sorts
    of settings..luminance/brightness/contrast. And because you're
    projecting a computer image you can do neat things like project
    mirrored images/negative/etc



    Cheers,
    -sd
    http://www.zoom.sh
     
    Some Dude, Oct 10, 2003
    #3
  4. Whatever you do, I love your enthusiasm for an adventure.

    I know I missed your postings of late. The recent past has been the
    Scarpitti volleyball on the beach fest. Welcome back.


    Robert Vervoordt, MFA
     
    Robert Vervoordt, Oct 10, 2003
    #4
  5. Some Dude

    Ken Hart Guest

    that.

    IIRC, that would be called a "Waterhouse stop" ? (useless trivia not really
    important to the issue at hand)

    My concern with this project would be (a) if the enlarger focuses at the
    distance/size you want to use; and (b) keeping everything lined up square
    away, perpendicular, plumb, and parallel. Experimenting would answer all
    this.

    Ken
     
    Ken Hart, Oct 10, 2003
    #5
  6. Some Dude

    Jon Guest

    It takes two to play volleyball. If there were no other players, that troll
    would go away.
     
    Jon, Oct 11, 2003
    #6
  7. Some Dude

    Sherman Guest

    Most slide projectors allow you to remove the lens easily. I wonder if
    making a Waterhouse stop (just a sheet or board with a hole in it for the
    aperture) and placing behind the lens would work to reduce the light level.

    A regular dimmer switch might work as well. If you are planning to do this
    very often perhaps buying a dimmer and mounting it in a project box along
    with an electrical outlet to plug your projector in and an a/c cord to plug
    the box into the wall.would be a good investment.

    Sherman
    http://www.dunnamphoto.com
     
    Sherman, Oct 11, 2003
    #7
  8. Some Dude

    Some Dude Guest

    Great responses. Thanks.

    I'm going to try several different ideas today and will report back...
     
    Some Dude, Oct 11, 2003
    #8
  9. Don't try using a dimmer if the projector has a fan; dimmers only work with
    AC/DC-type loads, not with AC-only motors. Might not hurt anything, but it
    could cause the motor to not work, leading to overheating of either bulb or
    possibly the slide/film.


    --
    Call the American Teleservices Association at (317) 816-9336
    and let them know just how much you appreciate their "services".
    Telephone # courtesy of Dave Barry (yes, that Dave Barry).
    (Read all about it on Slashdot:
    http://slashdot.org/articles/03/10/05/1350243.shtml?tid=103&tid=133&tid=158&tid=186&tid=99)
     
    David Nebenzahl, Oct 11, 2003
    #9
  10. Some Dude

    Some Dude Guest

    Good point.

    I did my tests and they came out just peachy.

    I took a few EIR slides and exposed them for about (about) 1/60 or
    about 1/30 (who knows, I flipped the projector light off and on as
    fast as I could)

    I got a few very nice negative prints out of the slide.

    Next test was removing the carousel and inserting a BW negative into
    the chamber. Got that "mostly" aligned and did that for about the
    same exposure time. Came out just fine, albeit a little bit
    overdeveloped (my bad).

    Next was getting a 5x7 thin, stretched canvas and mounting in front of
    the rc paper. about 1/2" sec. (so the light reflected through the
    canvas, dispersing it to all hell and then exposing to the paper
    behind it). I also did this in front of the lens but that was no good
    (no focus).



    Came out....weiiiiiiiiiiiiiiiiird

    The idea I had was to basically affix the rc paper onto the canvas and
    then expose through it. Focusing would be a bitch otherwise (or,
    impossible). Pretty cool.



    So yeah- pretty successful testing day :)
     
    Some Dude, Oct 11, 2003
    #10
  11. Some Dude

    Ken Hart Guest

    Keep in fan, that the dimmer switch is going to be carrying some hefty
    current (check the nameplate on the projector), also it is going to be
    "dimming" the blower fan. This could have adverse, possibly serious results:
    premature bulb failure, and/or fan motor burning up.

    Obviously, if there isn't a fan...

    Ken
     
    Ken Hart, Oct 11, 2003
    #11
  12. Some Kodak slide projectors, at least in the past, uses a 7-pin "remote"
    jack. Although I don't have a pinout available, I think it was the bottom 2
    pins that were used with multimedia program coltrollers to control light
    intensity. This allowed one to "fade" from full intensity to black within a
    programmed interval (eg. 4 second fade)

    Yup. A quick search yielded:
    http://www.rit.edu/~rckpph/faq/22.05.html
     
    Mark Wolenski, Oct 12, 2003
    #12
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