Paper Flashing.

Discussion in 'Enlarging' started by Stoo Batchelor, Dec 2, 2007.

  1. Stoo Batchelor

    Stoo Batchelor Member

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    Hi All

    Just a quicky.

    When flashing a small part of the printing paper (selective flashing) Do I need to move the card that I am flashing through, the same as burning a print, or is it o.k to just sit the card some distance from the easel and let the light do its thing.

    Thanks

    Stoo
     
  2. Les McLean

    Les McLean Subscriber

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    Stoo, move the card just you would when burning in otherwise there could be a danger of creating an obvious edge to the flashed area.


     
  3. Stoo Batchelor

    Stoo Batchelor Member

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    Thanks for that Les.

    Your timing was perfect as I am just about to shut the door and turn the lights out.

    Kind Regards

    Stoo.

     
  4. pentaxuser

    pentaxuser Subscriber

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    Can't be a bad site when you have almost the equivalent of Les in the darkroom with you.

    pentaxuser
     
  5. Henry Alive

    Henry Alive Subscriber

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  6. Dan Henderson

    Dan Henderson Member

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    Henry: I took a darkroom seminar with Les McLean last summer, and he highly recommends the RH paper flasher.
     
  7. Dave Miller

    Dave Miller Member

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    I have one in my darkroom. Nuff said?:smile:
     
  8. Lee L

    Lee L Member

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    Can you tell me why it's not a good idea to print and flash with the same enlarger? If you're thinking that pulling and replacing the negative is necessary, it's not. I've done this a lot in a production darkroom for custom hand made prints. I put a single layer of translucent milk-white plastic (perspex) in direct contact with the bottom of the enlarger lens and found through testing that a certain percentage of the main exposure gave me a good preflash exposure. That will vary with your set up, but it's simple and relatively easy to test for. If you have an enlarging meter, you could also test for what would be a measurable consistent preflash exposure.

    I'm not saying that a dedicated preflasher like the RH Designs model isn't a great tool. I'm saying that there's nothing wrong, inferior, or particularly hard about using the enlarger you're printing with for preflashing.

    Lee
     
  9. Trevor Crone

    Trevor Crone Member

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    I also use the same enlarger for preflash and can't see why it should be a problem. Although I must confess I have my eye on RH Designs paper flasher. Although the wife has already got me socks and pants for Christmas, so will have to wait 'til next year.
     
  10. Lee L

    Lee L Member

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    Good thinking. I understand that the use of pants for preflashing or flashing outside the privacy of your own home is not recommended. :smile:

    I intended, but neglected to mention that a white styrofoam drinking cup held over the lens also works well for preflashing with the enlarger and the negative still in place.

    Lee
     
  11. Marco Buonocore

    Marco Buonocore Member

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    Great idea, Lee. Can't wait to give that a try!
     
  12. tim rudman

    tim rudman Member

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    There is nothing wrong with flashing using the enlarger that you are printing with Lee. It's just either less accurate or it's less convenient - unless you always print with the enlarger at the same height, lens and f-stop for every print. Change any of these and the max-flash time will alter and you have to retest for it every time you make a print with a new neg (or etc). You can re-establish this with an exposure meter once you have calibrated for the paper to start with, or you can make a new flash test strip. Either way it's an extra calculation. If you have a 2nd enlarger or an independent flash light source it never changes and you always know exactly what the max flash time for that box of paper is, regardless of what neg or what magnification you are using for the print in question. It's just a simpler hassle free routine giving you predictable, controllable results in one step.
    Tim
     
  13. Lee L

    Lee L Member

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    Tim,

    I do understand the aspects you're talking about. My point is that being a bit more inconvenient doesn't make it a "bad idea", which sounds as though it won't work or is in some way materially inferior.

    I have used pre-flashing on hundreds of poorly exposed and/or overdeveloped negatives in a high volume custom printing setting, and gotten very good and surprisingly consistent results using a standard percentage of the required exposure time. Finer custom prints will obviously benefit from tighter tweaking, but the percentage of main exposure method is pretty sound, considering that it's an adjustment that takes into account the degree of enlargement, paper speed, and negative density.

    Lee
     
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  15. Henry Alive

    Henry Alive Subscriber

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    Hello again:
    I know it is perfectly possible to flash with a unique enlarger, but I have the same opinion than Tim Rudman. So, I ask again: Do you have an opinion about the paperflasher made by RH Designs?
    http://www.rhdesigns.co.uk/darkroom/...erflasher.html
    ... and thanks again,
    Henry.
     
  16. tim rudman

    tim rudman Member

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    Lee,
    You are quite right of course. If you have buttoned down a way that works for you, gives you full max flash without overspill into fog, each time based on experience - that's perfectly fine. If it works, it works. That's what counts.

    On the other hand, I have often read people describing on line a method of giving a bit of exposure through some diffusing material in an arbitary fashion as being the way to pre-flash. It's not. It needs to be done in a precisely measured or calibrated fashion to get predictable, repeatable and fully effective results without fogging. It's not remotely difficult but like most things in printing, it needs to be controlled for optimum results. (I'm making the assumption that we all want optimum results of course :wink:)

    Henry
    Apart from Dave, no one has answered your question yet, so here is my 2p worth.
    I would like to start by saying that I am a fan of RH Designs, I use their pro stop clock and I often demonstate it on B&W workshops and everyone immediately wants one! I don't use their paper flasher because I have 2 alternative set ups that I prefer.
    I have tested it and I did find that for my use there were drawbacks - not major, but it didn't offer me an advantage to what I use. This was mostly due to siting of the unit. If flashing the paper in the easel the flash light source needs to be in the lens axis otherwise 'shadow' artefacts may occur. A light shadow may appear next to the edge of a masking frame or blade, or a reflection may be thrown onto the paper from an edge of a 2 blade frame. the 1st will give a light 'shadow' (unflashed), the 2nd a dark shadow. These are more apparent with some masking frames than others (I have quite a few, generally 4 bladers are better)
    I also didn't find a really happy place for it. My ceiling was too high and anyway the unit had to be significantly off axis to avoid a shadow of the enlarger head. Applying it to the lens mounts with blue tac or similar tended to all too easily give alignment discrepancies from pressing it into place, which I am slightly paranoid about.
    I run 2 different flashing systems, both from my stop clock, which are very reliable for different purposes, and give me everything I want, so I don't use it.
    However, I also know that many people use the unit and love it - so hopefully some will now chip in and counter my views :smile:
    Hope this helps.
    Tim
     
  17. eclarke

    eclarke Member

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    I have the RH flasher too. It works really well and is a fair bit smaller and cheaper than another enlarger...EC
     
  18. Dave Miller

    Dave Miller Member

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    I have my RH Designs flasher light source mounted on the swing filter with velcro, so it's always ready to use and as Tim suggests, is right under the lens axis to give shadowless lighting. It needed a couple of test trips to establish times for various heights and papers that give a good starting point.
     
  19. jeroldharter

    jeroldharter Member

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    I have the RH Designs flasher also. Although a little pricey, it works great. The built in timer has a test strip mode making it easy to determine the proper flash time. I mount the light source to the lens board stage with some blue tack adhesive. The problem with that is that I have to do a test strip each time. Ideally, I would mount the flasher in a permanent position so that the flash time would always be ~ the same. The light source is very "wide angle" so it need not be mounted on the ceiling for uniformity.

    I would like to fashion a swing arm that folds the flasher against the wall when not in use, and then swings out under the lens to flash the paper when desired. The problem with that is if you make widely different print sizes like 8x10 and then 20x24. If you mount the flasher so that it can swing under the lens for the small print, then it might be too close to the paper to evenly illuminate the large print. But if you put it on the ceiling you might get shadows. I think you just have to do what makes the most sense for your work flow.
     
  20. michael9793

    michael9793 Member

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    One of the magazines this last month had a article about the RH flasher and what the photographer did was attach Velcro to the enlarger next to the lens and to the bottom of the flasher and did tests from different height and then used that on regulating his flashing. then it could be removed without and problem.


    michael andersen
     
  21. Brook Hill

    Brook Hill Subscriber

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    RH Flasher

    There is one technique that Les Mclean showed me on his workshop which I find useful and that is to use the RH flasher to burn in the very dense highlights using white light, a lot easier than trying to force light through the solid black neg. To do this it is easier if the flasher light is mounted on the enlarger by the lens. With the RH flasher in this set up the process is very easy to do, just got to make sure you can find the right spot an a blank piece of white paper.
    Tony
     
  22. tim rudman

    tim rudman Member

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    A relatively easy way of doing this on your blank piece of paper is to flash whilst you burn in at the same time, then you can see what you are doing. This is why I have 2 flashing set ups. One sits at the back of the darkroom and 'looks' up to the ceiling. The result is an omni directional low level flashing light which flashes, or even fogs if I wish, whilst making an exposure or burn in, but is not bright enough to make the projected image difficult to see. It is linked into the timer.
    (the other flasher is another adjacent enlarger for direct flashing)
    Tim
     
  23. ITD

    ITD Subscriber

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    Tim, what flashing system do you use, and how does it link into your StopClock?
     
  24. Les McLean

    Les McLean Subscriber

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    Henry
    Apart from Dave, no one has answered your question yet, so here is my 2p worth.
    I would like to start by saying that I am a fan of RH Designs, I use their pro stop clock and I often demonstate it on B&W workshops and everyone immediately wants one! I don't use their paper flasher because I have 2 alternative set ups that I prefer.
    I have tested it and I did find that for my use there were drawbacks - not major, but it didn't offer me an advantage to what I use. This was mostly due to siting of the unit. If flashing the paper in the easel the flash light source needs to be in the lens axis otherwise 'shadow' artefacts may occur. A light shadow may appear next to the edge of a masking frame or blade, or a reflection may be thrown onto the paper from an edge of a 2 blade frame. the 1st will give a light 'shadow' (unflashed), the 2nd a dark shadow. These are more apparent with some masking frames than others (I have quite a few, generally 4 bladers are better)
    I also didn't find a really happy place for it. My ceiling was too high and anyway the unit had to be significantly off axis to avoid a shadow of the enlarger head. Applying it to the lens mounts with blue tac or similar tended to all too easily give alignment discrepancies from pressing it into place, which I am slightly paranoid about.
    I run 2 different flashing systems, both from my stop clock, which are very reliable for different purposes, and give me everything I want, so I don't use it.
    However, I also know that many people use the unit and love it - so hopefully some will now chip in and counter my views
    Hope this helps.
    Tim


    I'll answer Henry's question and at the same time comment on Tim's response.

    Henry, I have used the RH Designs Flasher since before Richard Ross actually started to produce it commercially largely because the first flasher was made for me by RH Designs based on an idea that I had. I attach the light source to my enlarger, initially using blue tac, but now with velcro and have never encountered the problems suggested by Tim, namely enlarger alignment discrepancies or shadow effects. I do admit to using an enlarger alignment tool every time I make prints in my own darkroom but have attached the Flasher to all manner of enlargers when doing workshops and teaching in colleges throughout the country and have never encountered the above problems.

    I find the flasher an invaluable tool when having to deal with small highlight areas of the print that require selective burning in either to subdue the brightness or enhance highlight texture. Both operations being quite tricky to deal with by using a paper grade and image forming light. Tim has already stated that the Flasher is an excellent tool but prefers to use his own methods which do work, which I can testify to for I have seen him do it.
     
    Last edited by a moderator: Dec 10, 2007
  25. jgcull

    jgcull Subscriber

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    Why do you flash the paper? What is the effect on the image? Thanks!

    Janet
     
  26. RobC

    RobC Member

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    in a nutshell it has the effect of bending/lifting the toe of the paper towards or onto the the light sensitivity threshold of the paper.
    Therefore it only affects the hightlights of the area flashed. The result is that it can bring back into the print, some subtle highlight details that would otherwise be burnt out without having to adjust the contrast of the rest of the print.