Precision Enlarger Alignment

Discussion in 'Darkroom Developing and Printing' started by kenneth.kaiser, May 13, 2007.

  1. I recently designed, constructed, and tested a method of precision
    enlarger alignment.
    The method is obvious, and probably not original with me, but since I
    have not seen it anywhere else, I would like to post it for general
    interest. I wrote a description in a Word document with photos of the
    method, but when I tried to copy it in the space below, the photos do
    not copy.
    If someone would suggest a way to include the photos in the post, or
    another place to post it, I would be glad to share it with the
    group.
    Thanks
    Ken
     
    kenneth.kaiser, May 13, 2007
    #1
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  2. spake thus:
    Let me guess; does it involve two mirrors?

    If so, then this is indeed a very precise way to align *any* enlarger.
    (Assuming that the attitude of the enlarger head can be adjusted.)

    So far as your question goes, I would strongly advise against trying to
    post a raw, naked Word document. Piss-poor format for this kind of
    information interchange.

    Do you know enough basic HTML to make a simple web page with the
    instructions? If so, that would be the best way to post this (assuming
    you have access to a small amount of web space somewhere). If not, the
    2nd-best alternative would be to make a PDF from the Word document
    (assuming you have software to do this), upload the PDF to a web site
    and post a link to it.


    --
    Any system of knowledge that is capable of listing films in order
    of use of the word "****" is incapable of writing a good summary
    and analysis of the Philippine-American War. And vice-versa.
    This is an inviolable rule.

    - Matthew White, referring to Wikipedia on his WikiWatch site
    (http://users.erols.com/mwhite28/wikiwoo.htm)
     
    David Nebenzahl, May 14, 2007
    #2
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  3. kenneth.kaiser

    gr Guest

    An alternative way to post here is to use text only (not Word doc
    format) and draw rough diagrams using ASCII text keyboard characters.
    Kind of old fashioned but very universal.
    Example;
    .-. .-.
    .--' / \ '--.
    '--. \ _______ / .--'
    \ \ .-" "-. / /
    \ \ / \ / /
    \ / \ /
    \| .--. .--. |/
    | )/ | | \( |
    |/ \__/ \__/ \|
    / /^\ \
    \__ '=' __/
    |\ /|
    |\'"VUUUV"'/|
    \ `"""""""` /
    `-._____.-'
    jgs / / \ \
    / / \ \
    / / \ \
    ,-' ( ) `-,
    `-'._) (_.'-`
     
    gr, May 14, 2007
    #3
  4. WOW! I'm impressed.

    Ciao. Bogdan

    gr wrote:
    --
    ________________________________________________________________
    Bogdan Karasek
    Montréal, Québec
    Canada www.bogdanphoto.com

    "I photograph my reality"
    ________________________________________________________________
     
    Bogdan Karasek, May 14, 2007
    #4
  5. Bogdan Karasek spake thus:
    [snip example]
    Since you liked that, check these out. From my ASCII art archive:


    _____________________
    /| /| | |
    ||__|| | |
    / O O\__ |
    / \ |
    / \ \ |
    / _ \ \ _______________|
    / |\____\ \ ||
    / | | | |\____/ ||
    / \|_|_|/ | __||
    / / \ |____| ||
    / | | /| | --|
    | | |// |____ --|
    * _ | |_|_|_| | \-/
    *-- _--\ _ \ // |
    / _ \\ _ // | /
    * / \_ /- | - | |
    * ___ c_c_c_C/ \C_c_c_c____________



    |\ _.-'~~""'~`'~)
    /, ~-,__,,,.'~ ,-;;--''
    |,4) ./ ' ; ;/'
    '-~~;'@ ( ; ;
    _.--'' _.-_..' .;.'
    (,_..----''' (,..--''


    __ __ __ _
    | / \ /\ |_ |__||_ /\ | \
    |__\__//--\| | ||__/--\|_/

    ___
    - - _( (~\
    _ _ / ___ ___ \ ( \> > \
    -/~/ / ~\ |/ V \ | _ > /(~\/
    || | | /\ ;\ | _ _ \| ( \/ / /
    _\\)\)\)/ ;;; | ~) (~ |/) \ \ //
    ///(())(__/~;;\ | | / (_._/ /
    (((__ __ \\ \ | "") ' ;:' i
    )))--`.'-- (( ;,8 \ \ <XXX> /| ;. ;.
    ((\ | /)) .,88 `: ..,,;;;;,-.. \_ __/ | ;[8: ;
    )| ~-~ |(|(888; ..``'::::8888oooooo/| -- \~--._ |88::| |\
    -===- /| \8;; ``:. oo.8888888888:`((( o.ooo8888Oo;:;:' |
    |_~-___-~_| `-\. ` `o`88888888b` )) 888b88888P""' ; ;
    ~~~~;~~ "`--_`. b`888888888;(.,"888b888" ..::;-'
    ; ; ~"-.... b`8888888:::::.`8888. .:;;;''
    ; ; `:::. `:::OOO:::::::.`OO' ;;;''
    : ; `. "``::::::'' .'
    ; `. \_ /
    ; ; +: ~~-- `:' -';
    `: : .::/
    ; ;;+_ :::. :..;;;



    --
    Any system of knowledge that is capable of listing films in order
    of use of the word "****" is incapable of writing a good summary
    and analysis of the Philippine-American War. And vice-versa.
    This is an inviolable rule.

    - Matthew White, referring to Wikipedia on his WikiWatch site
    (http://users.erols.com/mwhite28/wikiwoo.htm)
     
    David Nebenzahl, May 14, 2007
    #5
  6. Hi,

    Now that's a double WOW WOW!. Really cool. remember students doing
    these when we got our first Apple computers at school back at the dawn
    of time :)

    Cheers,
    Bogdan

    --
    ________________________________________________________________
    Bogdan Karasek
    Montréal, Québec
    Canada www.bogdanphoto.com

    "I photograph my reality"
    ________________________________________________________________
     
    Bogdan Karasek, May 14, 2007
    #6
  7. I am posting the document text which should describe the alignment
    method well enough to determine interest. If any one is interested in
    more information, I can forward the word document, with photos to
    them. I have seen this alignment method used extensively on optical
    benches, but not on enlargers.
    Thanks
    Ken
    Precision Enlarger Alignment System Kenneth W. Kaiser

    1) Introduction

    I purchased a used Omega D-2 enlarger for making 16 by 20 inch prints
    from 4 by 5 inch negatives and 20 inch long prints from 5-inch long 35
    mm panoramic negatives.

    After refurbishment and installation of a good enlarger lens, came the
    task of enlarger alignment.
    I tried levels, rulers and squares, two mirrors looking at each other,
    but could never get a good sharp edge-to-edge image on the enlarger
    easel to my satisfaction.

    The problem with these methods, and others that were not tried, is
    that they really do not align the plane of the actual negative to the
    plane of the enlarger easel.

    I decided to install tilt and swing adjustments on the enlarging lens,
    just like the 4 by 5 view camera, and use the Scheimpflug Principle
    for enlarger alignment.

    The tilts and swings are adjusted with the negative in place and a
    wide-angle grain focuser on the easel.

    This method of alignment worked so well that I made a second tilt-
    swing alignment assembly for my 35 mm enlarger.

    Mathematical analysis indicates that only a small amount of tilt-swing
    adjustment is needed for alignment of the actual negative plane to the
    plane of the enlarger easel.
    The two cases considered are a 4 x 5 inch negative enlarged to 16 x 20
    inches and a 35 mm negative enlarged to 8 x 10 inches.
    Calculations show that + / - 1/8 inch of easel tilt requires + / -
    0.0078 inch of negative tilt for sharp focus with the 4 x 5 inch
    negative.
    For the 35 mm negative, + / - 1/8 inch of easel tilt requires + / -
    0.00125 inch of negative tilt for sharp focus.

    Standard micrometer heads were used for precision adjustment of the
    lens plane. Micrometer heads provide a smooth precision adjustment of
    tilt-swing and are easy to use in the dark.

    2) Tilt-Swing Alignment System Description

    The tilt swing alignment system consists of two flat aluminum plates
    5.5 by 5.5 by 0.25 inches. Each plate has a hole in the center. The
    lens is mounted on the lens plate. The enlarger plate is mounted to
    the enlarger at the lens location and has a hole in the center for the
    light to enter the lens. Figure # 1 shows the overall assembly
    installed on the 35 mm enlarger. Figure # 2 shows the alignment
    assembly installed on the Omega D-2 enlarger. Figure # 3 shows the
    alignment assembly mounted on the Omega enlarger cone.

    Precision Enlarger Alignment System Kenneth W. Kaiser page 2



    Figure # 1



    Figure # 2




    Precision Enlarger Alignment System Kenneth W. Kaiser page 3




    Figure # 3

    The lens is mounted at the center of the lens plate.
    The lens plate has three 0.375-inch holes drilled in it at location C
    and three 0.25-inch holes drilled in it at location M in Figure # 4.

    The enlarger plate has three 0.25-inch by 20 tapped holes in it on
    centers of the C lens plate holes labeled S in Figure # 5.

    The lens plate, with lens, is spring loaded to the enlarger plate with
    three compression springs mounted with 0.25 by 20 by 1 inch bolts at
    location S. See Figure # 6












    Precision Enlarger Alignment System Kenneth W. Kaiser page 4





    Figure # 6

    Three micrometer heads are mounted to the lens plate at location M,
    each with a 4 - 40 set screw.
    When the micrometers are adjusted, they push the lens plate away from
    the enlarger plate. Adjustment of the three-micrometer heads provides
    both swing and tilt to the enlarger lens.
    The two-plate assembly is mounted to the enlarger with two 6 - 32 nuts
    and bolts.
    The assembly is oriented with two-micrometer heads at the rear of the
    easel and one head in front. This orientation is shown in Figures # 1
    and # 2.

    Although there are alternative geometries for lens tilt and swing,
    this geometry is easily constructed with common household tools.

    3) Use of the Alignment System

    Tilt and swing is set to zero by adjusting the three-micrometer heads
    for a uniform gap between the lens plate and the enlarger plate.
    This is easily done with a 1/8-inch diameter drill rod for a gauge
    between the two plates.

    A wide-angle grain focuser is used to focus the image at the center of
    the easel with the enlarger focus knob and tilt-swing set to zero.

    Precision Enlarger Alignment System Kenneth W. Kaiser page 5

    The lens optics causes an adjustment reversal through the lens.
    The wide-angle grain focuser is placed at the lower left corner of the
    easel and the rear right micrometer head is adjusted for sharp focus.
    The grain focuser is placed at the lower right corner of the easel
    with adjustment of the rear left micrometer head for sharp focus.
    The grain focuser is then placed at the upper center of the easel and
    the front center micrometer is adjusted for sharp focus.

    The focus at the center of the easel is rechecked for sharpness.
    It is usually still sharp, but if not, repeat the process and a second
    go around is all that is needed.
    I check alignment after changing negatives, and often find that it
    must be adjusted again. This sensitivity is evidence that the
    conventional methods of enlarger alignment are crude and alignment can
    be improved with a tilt-swing system like this.

    This system provides good sharp edge-to-edge image focus, which is
    further improved by stopping down the enlarger lens.

    3) Materials

    Micrometer heads, quantity 3
    Micrometer heads are available from www.use-enco.com.
    Model # 604-2200 is about $39 each
    Aluminum plates 5.5 by 5.5 by 0.25 inch, quantity 2
    Springs, quantity 3
    Springs are obtained from a local hardware store and size is
    determined by inspection
    Bolts ¼ - 20 - 1 inch, quantity 3
    Set screws, 4 - 40, quantity 3
    Bolts, 6 - 32, quantity 2
    Nuts, 6 - 32, quantity 2
    __________________
    __________________
    ! S
    S ! ! !
    ! ! !
    C M C !
    !
    LENS ! ! !
    !
    HOLE ! !
    LENS !
    ! ! ! !
    !
    S ! ! M
    C M !
    !_________________! !
    _________________!

    Figure # 5 Enlarger Plate Figure #
    4 Lens Plate
     
    kenneth.kaiser, May 15, 2007
    #7
  8. kenneth.kaiser

    dan.c.quinn Guest

    There are two conditions for exact alignment.
    First the planes of the negative and easel must
    be parallel. Second the optical axis of the lens
    must be perpendicular to both the negative
    and the easel.

    If the projected image of a square object is square
    upon the easel then the two conditions have been
    met.

    Any body who has made the minute adjustments to
    negative and lens stages knows the process can be
    frustrating. A few hand tools, a square, and high
    power reading glasses have done for me. Now
    I've doubts the glasses are needed. Dan
     
    dan.c.quinn, May 16, 2007
    #8
  9. Dan, this is one condition for enlarger alignment.
    There are other conditions.
    My method is according to the Scheimpflug condition.
    Thanks for posting.
    Ken
     
    kenneth.kaiser, May 19, 2007
    #9
  10. spake thus:
    [snip text of alignment procedure]

    I think the idea is interesting, if overkill for the application.

    One question: for the three "tilt and swing" adjustments, couldn't you
    just as well use some other threaded system, like ordinary screws,
    bolts, nuts, or turnbuckles, rather than expensive micrometers?


    --
    Any system of knowledge that is capable of listing films in order
    of use of the word "****" is incapable of writing a good summary
    and analysis of the Philippine-American War. And vice-versa.
    This is an inviolable rule.

    - Matthew White, referring to Wikipedia on his WikiWatch site
    (http://users.erols.com/mwhite28/wikiwoo.htm)
     
    David Nebenzahl, May 19, 2007
    #10
  11. Calumet used to make a lensboard that allowed you to change the
    alignment of the enlarging lens.

    Btw., my favorite way to align my enlargers is to use a Versalab
    Parallel laser alignment tool. It works very well.
     
    peter.desmidt, Jun 27, 2007
    #11
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