Cold light DIY project - beginner's questions

Discussion in 'Enlarging' started by Murray@uptowngallery, Oct 14, 2003.

  1. Murray@uptowngallery

    Murray@uptowngallery Member

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    Hello:

    I am going to build some horizontal cold head enlargers (6cmx9cm thru 4"x5" or 5"x7" and something larger to cover 8x10 and maybe larger 11"x14" because I have huge monochromatic lens that was made for 15"x21" film and I just want to do it.

    1) Low budget

    2) I'm in no hurry

    3) That's just the way I am - if I can build something myself, I try. Sometimes this violates rule #1 above, but I learn something in the process.

    4) If someone tells me something can't be done, that's one more reason for me to try.

    5) A whole lot of other odd reasons we don't have bandwidth for.

    6) It keeps me off the street.

    I have read another post about the evolution of the Aristo light source and
    have some questions.

    I had focussed (haha) on a multi-tube blue fluorescent source of 420 nm (unless I can find an economical serpentine lamp source; not likely) with individual electronic fluorescent ballasts (dimmable) diffused thru white opaque acrylic. I have a foot lambert photometer and between adjusting the output of individual lamps and rear mounted reflectors I'll work on getting even illumination thru the optics.

    Using a lamp with a strong 420 nm spectral component, I am assuming graded contrast paper will work and is still available.

    I understand VC paper is used by somehow determining how much exposure with blue and how much with green. I'm not sure if this is measured and calculated or trial and error. What I don't understand is how the two different emulsions produce different appearance...is one 'faster' than the other and one is for dark and one is for light...kind of like the printing side of Zone method?

    Is it possible to get a decent range of density with blue light only and graded paper (if it's still made)?

    Thank you

    Murray
     
  2. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member Moderator

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    Yes, graded paper is still made, and some of us even prefer it. The older Aristo heads put out a greenish light.

    For 4x5" and smaller, you might just get a Graflarger head that will fit on any 4x5" camera with a Graflok back and concentrate your efforts on a larger head for a bigger enlarger. Graflarger backs can often be found for around $100 or less, and Aristo can even upgrade the tube.
     
  3. Loose Gravel

    Loose Gravel Member

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    420nm is very blue. I don't know how "strong" the 420nm is. The graded papers will see it very well, but vc paper will print hard. It will be hard for you to see and focus and dodge if the 420nm is the only light there. Maybe consider some light that you can see if your tubes are too pure blue.
     
  4. Murray@uptowngallery

    Murray@uptowngallery Member

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    Ugh, bad pun.

    The lights I'm considering are Super Actinic 3 fluorescents. They peak at 420 for marine/coral fish tank applications but should have some other wavelengths too...

    Murray
     
  5. Donald Miller

    Donald Miller Member

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  6. Murray@uptowngallery

    Murray@uptowngallery Member

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    Hello:

    I've done roughly that...downloaded a few paper spectral response curves then compared various lamp curves...I was eager to try pulsed xenon, but unless I find surplus equipment that's beyond my technical ability and sanity...the electric bill and fire hazard are enough to scare me off.

    I know electronic fluorescent ballasts well enough; I designed some for two years. The standard fluorescent lamp fare, however, seem to have poorly compatible spectra, at least the main components are way off the paper wavelengths.

    The few graded papers I could find data for peaked at 425-450 nm or so. Black light blue lamps are centered around 350 nm with some content in the 400-450 range but most of the energy would be wasted. These lamps are cheaper than the Actinics, however.

    I've got some more ideas to mull over...

    Murray
     
  7. Murray@uptowngallery

    Murray@uptowngallery Member

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    Next question -

    does photomural roll paper come in graded?

    Thanks
     
  8. Donald Miller

    Donald Miller Member

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  9. Murray@uptowngallery

    Murray@uptowngallery Member

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    Thanks...

    I have emailed Tom.

    Clyde's wife or administrative assistant apparently answers his email...the reply to a separate subject inquiry was 'spin' about how he only uses the latest modern technology.

    I took that to mean he was busy (a professional, not a amateur with the time to ponder bizarre ideas) and didn't pursue that avenue.

    Murray
     
  10. Ole

    Ole Moderator Staff Member Moderator

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    How big is "mural"?

    Several MACO papers come in rolls of 108cmx10m or 125cmx10m, including both graded and variable, fiber and resin base. Even linen base...
     
  11. Murray@uptowngallery

    Murray@uptowngallery Member

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    That's great info - just 'large' this is exactly what I was looking for...the roll economy is nicer than individual sheets.

    Practicality of storage is another question.


    Thank you.

    Very nice to get answers instead of ...

    "Why bother?" answers typical of photo.net!

    Murray
     
  12. DKT

    DKT Member

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    try Luminos for graded mural paper.

    http://www.luminos.com/

    fwiw--they used to make fiber based murals in-house where I work -- we still have several rolls of paper left over ...at any rate, most of them are either the Kodak Mural paper--this was sorta of a single-mid type weight fiber paper with really good wet strength, for hand processing. There are also rolls of Ilfobrom and Kodabromide--as well as RC Multigrade III, and at least one of Kodabrome graded RC, which is only maybe a few yrs old, but would be discontinued now. FWIW, with the exception of the Multigrade, the others are all graded.

    the paper sizes are usually in the 30-42,48 inch width range with a length of 100 feet. You may be able to find some 52 inch widths, but probably not in fiber....

    *just checked the luminos site, and yes they do have 51 inch fiber. so there ya go--now you just need about 2-3 5x9 foot sinks....

    hope this helps

    KT
     
  13. Murray@uptowngallery

    Murray@uptowngallery Member

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    Hello:

    Big sink...

    I'm thinking about "tube" developing using 'tubes' made of recycled 55 gallon plastic drums.

    I haven't figured out how to seam two together leak free yet.

    Murray
     
  14. Donald Miller

    Donald Miller Member

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  15. Aggie

    Aggie Member

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  16. DKT

    DKT Member

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    Aggie's got the right idea--it doesn't have to be that complicated. You just need alot of room that you can be messy in--slosh chemistry around etc. Some folks will dilute developers down more than normal and then sponge these on by hand in sections etc.

    The place where i work has had at least 2 darkrooms over the years--our new one, is actually designed to make murals in--very long for horizontal projection with an alcove for a roller processor. We've only made maybe 3 mural sized prints in this though, since we send that work out now. We did these using a 20 inch roller transport processor and tiling strips of mural paper together. These were last-ditch, final hour efforts because of someone's (sigh) poor planning...needless to say those involved didn't enjoy that day at work...

    The old darkroom was a monster as well--There were 2 5x9 foot sized kreonite sinks arranged in an L pattern with a fume hood above them. The sinks had standpipes & water panels and water recirculating jets built into the corners. You could fill them up with chemistry to process the paper, and then turn them into print washers, or use one for a water rinse prior to the fix.

    They chewed up a good 25-30 gallons of chemistry for each sink, and disposal of the fix was problematic which is one of the main reasons they stopped making prints this large in-house. Plus it was a time-consuming PIA....

    What they did was to build risers alongside the sinks, so you could walk back & forth to agitiate the print--at about knee height. They also had some home-made tubes that were big sections of PVC--and they swirled the paper around in these things to agitate. My boss tells me they pretty much sucked..I only made "large" prints in this old lab using trays that were in the 3x3 foot range. You can get trays up to 40 inches, or just under 40 but they cost quite a bit....

    At any rate, it just depends on how much you plan on doing this. If it's just now & then, you can cobble almost any setup together--if it's more than that, you might want to consider paying a lab to do it....in almost every way, it's worth it (to me anyways).

    Hope this helps--

    KT

    guess my employers would want me to say these are my opinions only.
     
  17. Murray@uptowngallery

    Murray@uptowngallery Member

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    Another good source I found (I think) was a Rubbermaid horse watering trough....economically priced, and has a space where plumbing can be hooked up for drainage...

    They don't come with covers :O)

    They also don't fit in my car.

    If you live in the Big City, you probably don't have such a source nearby.

    Murray
     
  18. Murray@uptowngallery

    Murray@uptowngallery Member

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    mural, mural, on the wall

    Long lost replies...

    Yes, 1 meter wide by longer than any sheet size is very nicely 'mural'...not sure why they call ti that, other than perhaps 'wall-sized prints'.

    Thanks, Ole, for the Maco lead.

    I wonder what Donald Miller meant by "OOO"...is that three O's, like, really impressed, or three zeroes, like really NOT impressed :O)

    Murray
     
  19. lee

    lee Member

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    when you tried to delete a post in the old forum you it would not let you out if there was nothing there. So, you hit edit and delete everything and then put in some symbol (Aggie used .. and Don uses 000) that is all that is happening.

    lee\c
     
  20. sanking

    sanking Member

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    BTW, just in case anyone is interested I have 5X7" Arista cold light head with the Variable Contrast light, I think it is called the V-64, that i will part with at a very reasonable price.

    Anyone interested just contact me off the forum at sanking@clemson.edu.

    Sandy King