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Thread: XXL enlargement

  1. #21
    Bob Carnie's Avatar
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    Practice makes perfect

    Quote Originally Posted by gattu marrudu View Post
    That's great. Thanks a lot for the precious advice.
    A few things:
    - How does an apo lens improve the quality? By reducing diffraction?
    - You enlarge up to 12x according to what you write - I will have to enlarge from tiny details up to 100-150x. That would probably make a difference in terms of reprocity, exposure times and related heating issues.
    - I use some home made Ansco 130 developer for printing large format. This is an amazing developer, it lives forever (useful when you make a lot of it), especially when you use it at stock solution for maximum contrast.
    - I also use a sponge from time to time, although using gloves and dipping your hands in the chemicals might be more effective. I discussed the paper processing in another thread though, and probably the best solution is rolling the paper in a half pipe shaped tray.
    - Washing is an issue indeed. How about rolling the paper vertically in a large tube and flooding it like a film reel? Maybe even sealing the bottom end and leaving just a small drain tap so the cehemicals will flow down to the bottom like in an archival washer.

    I know there is a lot to build and experiment. My whole photography career has been about it.

  2. #22
    Ian Grant's Avatar
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    Quote Originally Posted by Bob Carnie View Post
    I am blushing Thomas

    I am making 30x40inch murals from Guillume Zilli pinhole 35 as well as 40x50 inch mural from 8x10 with no issues.

    things to consider when making large sharp murals

    Black wall darkroom and surrounding to behind the Enlarger setup
    this is probably arguable by some workers , but I have done enough murals to know that this is a critical element.
    Good optics with glass carriers, with laser aligned walls, no skimping on this-very very very critical
    I use Apo lenses whenever I can .-Critical
    Magnet wall so to hold the paper.- Critical
    Vacumn system though a good idea really needs a huge system to hold fibre and I have never seen the system that could do the job properly therefore good magnets
    two stop down as normal printing- critical
    mask out negative so no flare. Critical
    Dodging and Burning is the same as a small print , just a bit more difficult as you need to work from the side of the enlarger and practice until you get it.
    Full test strips rather than step offs, and one waste sheet for dodge and burn.
    Split contrast is easily done with the larger enlargers and nothing changes in that respect.
    If you are using a good enlarger the basic exposures should be in a realistic time line and is not a issue.

    Fresh chemistry and lots of it
    A normal negative should react basically the same for a 8x10 inch print vs a 40 x50 inch maybe a slight boost in contrast is required.
    I use a 3.5 min dev time, acid stop double fix .
    I use time temp method, since I am using 40 litre chemistry and my darkroom is humidity and temp controlled it is hard to move this chemistry's temp if the ambient is at 70.
    I use hypo clear and the wash is quite a proceedure.
    A hot developer is good beside the dev tray to take care of small isssues. dipping a sponge and putting on the emerging print where needed.
    this is why I like lith printing as it forces you to look at a print in the dev and any hot spots can be treated quite easily

    Hot press the murals and mount to either Acid Free Rag or Diabond

    hope this helps
    Walking into a mural assignment is not taken lightly and all of the above is important and as well a good assistant.
    Do not take on a mural print project unless you have time and willing to finish off the wash process in the single run.

    It should be pointed out that all of the above my opinion only and is what I consider when making prints.. these points are not end all be all, have to happen , but from my perspective to make gallery quality prints that photographers will buy it is essential.
    The smell comes back

    Have to agree, many lenses were APO before Canon made the term a desirable sales feature, so suddenly one day a lens was sold as an APO without any changes except to the name

    Ian

  3. #23
    Bob Carnie's Avatar
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    BTW if anyone needs the formulas I am using , I defer to Ian Grant who has helped me economise and work from scratch formulas.

    He is the man.

  4. #24
    Guillaume Zuili's Avatar
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    And the day Bob will spell or say my name right, cows will fly...!
    But for murals listen to Bob.
    :-)

  5. #25

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    Quote Originally Posted by Bob Carnie View Post
    BTW if anyone needs the formulas I am using , I defer to Ian Grant who has helped me economise and work from scratch formulas.

    He is the man.
    Which formulas do you use?
    For my latest large format project I used Ansco 130 (I get glycin in 500g cuts from Photographer's Formulary when I am in the USA since it looks impossible to find in EU); acetic acid (but I will use citric acid next time! That stuff smells in wide containers); double plain hypo fix (sodium thiosulfate + sodium sulfite - http://www.heylloyd.com/technicl/plain.htm ) and a separate acid fix for test strips so I don't pollute the one reserved for final prints; selenium toner 1+25 OR Agfa Sistan (very useful to get an uniform drying, acts as a wetting agent). Water at each step.
    I think this is a pretty economical and effective concotion.

    As for the enlarging plane, as Bob suggested, I might use a thick wood board with a steel plate attached, so I can use magnets.
    SoFiET
    lii.cc

  6. #26
    Ian Grant's Avatar
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    Would rather keep the final formulae between Bob & myself.

    However essentially a PQ Universal type developer, as they are clean working and economic, a Rapid fixer - essential with large images, and a wash aid based on Sodium Sulphite.

    Ian

  7. #27
    2F/2F's Avatar
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    1. Take 35mm film and enlarge onto 4x5 film to end up with a 4x5 reversed film interpositive.
    2. Take 4x5 film and enlarge onto 8x10 film to end up with a correctly-oriented 8x10 working negative.
    3. Take 8x10 working negative to a professional lab and have them print a 4x6 foot print from it.

    When you take the 8x10 working negative to them, they will only have to do a 6x enlargement (a tiny bit more, actually).

    I suggest litho film and a continuous tone developer that I use called Soemarko's LC-1. This will make the whole stepping up process able to be done in red light (as opposed to total darkness), and will make it much more affordable than using "good" film.

    The formula for LC-1 calls for three parts, but in group lab periods, I often mix up a faster-working ready-to-use solution, bypassing the parts. I have come to prefer the convenience of this directly-mixed version. This is my formula for a gallon of the stuff:

    1. 3 L water, brought to about 50 C
    2. 5 g - 6 g metol
    3. 5 g - 6 g hydroquinone
    4. 100 g - 120 g sodium sulfite
    5. 5 g - 10 g sodium bisulfite (The more you use, the slower the film will achieve contrast. Use more for contrastier negs, and less for flatter negs.)
    6. water to make 4 L

    - Let cool to room temperature before using.
    - Use in a tray in red light.
    -Expose for low tones. Develop for high tones. Development time will depend on contrast desired, and can range from 2 minutes to over five minutes depending on negs and contrast desired.
    - Pour back used developer from tray into jar.
    - Toss and make more when it loses its punch (takes much more than 6 minutes to develop)

    Note: Negs will have a warm tone, but this is irrelevant, as they are not the final product.

    Make your interpositive of such a contrast that it includes all detail and texture you may wish to incorporate into your final print. For the interpos, too flat - even waaay to flat - is better than too contrasty. The important thing is only to transfer all detail you want to have the option of using. You just need the raw materials for crafting the working negative to be present in the interpos. You can step up your contrast when you make the working neg, and it can again be stepped up when making the print.

    When making the working negative, LC-1 may not give you enough contrast for what you want, even with extended development times. If so, there are many other developers you can use. I would start with a dilute form of HC-110, used one shot, and gradually and small amounts of A+B working solution to raise contrast if needed.

    Worry more about the contrast on your working negative than on your interpos. It is what the print will be made from. I suggest using contact prints as a rough estimate of contrast required for the print.
    2F/2F

    "Truth and love are my law and worship. Form and conscience are my manifestation and guide. Nature and peace are my shelter and companions. Order is my attitude. Beauty and perfection are my attack."

    - Rob Tyner (1944 - 1991)

  8. #28

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    A Rodagon G is indispensible for making murals. If you're in perfect alignment there is no reason not to use this lens at wide open. As for holding the paper flat, I find magnet's to be a PITA - the rare earth variety are too strong and the strips not strong enough. Not to mention the fact that you'll have a very hard time getting your enlarging surface planar if you try attaching sheet metal to wood - a perfect plane to project on is essential for critical printing especially when using the optimal f-stops. Instead of magnets, I prefer using 1/8" x 2" x 5' lengths of steel flat bar wrapped in gaffer's tape - so much easier. No need for a vacuum easel either as the natural curl of the paper will lie flat if weighted. Having a flat flat surface to enlarge on makes it easier to keep things sharp when working with small negs- try mdf (you can get it in five foot wide sheets) or even better yet, a sheet of covered aluminum honeycomb from either paneltec or alcore as it's much much lighter (something to consider if, like me, you do not have a commercial drkrm. with a dedicated mural set-up). Different strokes for different folks however I've honed my technique within the constraints of the space I work in. I get tack sharp murals from all formats on paper up to 60" wide so I've never felt the need for internegs. The most important thing to remember before you go mcgyver on this...K.I.S.S.

  9. #29
    Marco B's Avatar
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    You may get some further ideas from the work of John Chiara and his Ultra Ultra Large Format camera. Some of his processing work is shown too in this video:
    [YOUTUBE]http://www.youtube.com/watch?v=9xYWehyfFcM[/YOUTUBE]

    Marco
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    "The nineteenth century began by believing that what was reasonable was true, and it wound up by believing that what it saw a photograph of, was true." - William M. Ivins Jr.

    "I don't know, maybe we should disinvent color, and we could just shoot Black & White." - David Burnett in 1978

    "Analog is chemistry + physics, digital is physics + math, which ones did you like most?"

  10. #30
    ic-racer's Avatar
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    Some math (re value of internegative for big enlargement)

    DIRECT:
    35mm to 4x6 feet = about 50x enlargement
    f8 on lens = f416
    best resolution on your printing paper is going to be about 5 lp/mm


    INTERNEGATIVE:
    35mm to 8x10 positive film = 7x
    f8 on lens = f64
    best resolution on internegative = 23 lp/mm

    8x10 negative to 4x6 feet = 7x
    f8 on lens = f65
    best resolution on paper = 23 lp/mm which will just equal what is in the internegative and is better than the DIRECT way. Even if you stop down your 300mm enlarging lens to f11 or f16, you still will be ahead of the direct route.


    (nice coincidence that with an 8x10 internegative both steps are about 7x enlargement )

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