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  1. Re: Headless LF Enlargers Rise UP!.....................LED

    Yes, sort of. There are many caveats. But the principle does work. See here for extensive discussion, experiments and proofs of concept:...
  2. Re: Headless LF Enlargers Rise UP!.....................LED

    No worries, you'll rarely catch me on that. As well as dogs.
  3. Re: Headless LF Enlargers Rise UP!.....................LED

    I thought this thread was about random non-sequiturs loosely related to enlargers.
  4. Re: Headless LF Enlargers Rise UP!.....................LED

    I am. Many other are, too. Perhaps not in the LF scene, but over at Photrio there's a pretty active interest in optical RA4 printing.
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    Re: 2013 5X7 Enlarger LED Experiment Parts

    Not all led power supplies are created equal, sadly (or perhaps fortunately - they might all have been junk in this respect).
    Case in point: I purchased a led strip + fitting power supply the other...
  6. Re: Potentially useful LEDs for darkroom/alt applications

    Lucky you. My first LED color head had around 100W net power. This was insufficient to conveniently print on warm tone paper from 35mm negatives onto sizes of 11x14". I like to keep exposures between...
  7. Re: Potentially useful LEDs for darkroom/alt applications

    Yeah, there's many challenges Tin Can, I know. Before you know it you'll be going through a crash course of electrical engineering instead of making images. 'Luckily' for me electronics has always...
  8. Re: Headless LF Enlargers Rise UP!.....................LED

    Yeah John, the design doesn't have to be complicated for it to be good. However, coming up with a really good and yet simple design can be a...complicated effort! Especially if it also needs to be...
  9. Re: Headless LF Enlargers Rise UP!.....................LED

    The problem with designing a head isn't really the light source. So many options, most of them achievable at low cost, and often with DIY-friendly components.
    The real issue is the negative and...
  10. Re: Potentially useful LEDs for darkroom/alt applications

    Re: the blue led wavelength: the usual wavelength is/was indeed something like 470nm or so, but these days, you can get pretty much any hue ranging from 365nm (UV) all the way down to IR in narrow...
  11. Re: Potentially useful LEDs for darkroom/alt applications

    There's a good chance that this will happen - sooner or later someone with the same enlarger will crack that nut and talk about it. The only problem, as you may have noticed, is the enormous choice...
  12. Re: Potentially useful LEDs for darkroom/alt applications

    Well, nothing wrong with using high CRI leds for the purposes you mention. It's one way of getting there. I must vehemently disagree on the notion that appropriately chosen blue/green or RGB leds...
  13. Re: Potentially useful LEDs for darkroom/alt applications

    In all the applications you mention, you need to ask yourself to what extent the availability of a continuous spectrum is in fact beneficial. The comparison with incandescent bulbs is tricky and I'd...
  14. Re: Potentially useful LEDs for darkroom/alt applications

    High CRI isn't really necessary for an enlarger light source. It even isn't for color, and for B&W it's entirely superfluous. It doesn't hurt either, of course, but it's just not a relevant...
  15. Re: Lowest temperature for C-41 / E-6 cross-processing?

    Indeed, bleach and fix aren't time critical; they just need to go to completion. If you use a stop bath (perhaps with an additional rinse for good measure), bleach and fix could also be done in room...
  16. Re: Lowest temperature for C-41 / E-6 cross-processing?

    You'll be fine; can't vouch for E6, but C41 works OK at room temperature - provided you're not interested about color accuracy, but you explicitly stated you aren't, so that's fine. The drawback is...
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    Poll: Re: poll Color Film Use

    That says something about your financial commitments into this. It doesn't answer the questions of Wayne: who's asking, and why?

    I also think the brackets are poorly chosen. I think there's a lot...
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    Re: Pyrocat HD solution B question

    Yeah, sounds like you had a drop of A carry over into B when you mixed it. It's not a big problem. Carry over of B into A would have been a problem; the other way around isn't very problematic.
    What...
  19. Re: About red safelights. How much red is damaging for the paper

    Can you name one B&W paper that is in current product and that's sensitive to red light? I can't think of any.
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    Re: Flare or light leak problem

    I'd say: lens not mounted properly to the lens board. Look at the circular pattern. It's light falling through a slit between the lens barrel and the board. Remount the lens onto the board, ensuring...
  21. Re: About red safelights. How much red is damaging for the paper

    Hehe, alright :)
    Looks like mine won't make it to the 10~50k hours as were about to move to a different house so I'm going to redo everything anyway. Haven't decided yet on the new setup except...
  22. Re: About red safelights. How much red is damaging for the paper

    Any particular theory behind this? Given the fact that most led strips are simply a couple of leds in series with a current limiting resistor, this approach would either have the leds burn dimmer...
  23. Re: About red safelights. How much red is damaging for the paper

    That will most likely be challenging, as daylight is pretty powerful and is of course full spectrum, so any filter you use will have to be *extremely* effective. In practice, filters can be good, but...
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    Re: 2013 5X7 LED Enlarger Head Test 2

    It's far^3 complicated indeed.
    But also functional^3. That's the thing.
    It's not hard to get 'something' to work with LEDs for B&W. Getting something to work WELL for B&W + color is a different...
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    Re: 2013 5X7 LED Enlarger Head Test 2

    I've been playing this game too
    https://www.photrio.com/forum/threads/color-enlarging-ra4-with-leds-continued.185864/
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    Re: How fast can an enlarger shutter be fired?

    You'd have to experiment, but I have my doubts you'll be able to make this fast enough for, say, something like 1/100. 1/10 and thereabouts, probably not a problem. But faster than that and you'll...
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    Re: 2013 5X7 LED Enlarger Head Test 2

    Simple. Maybe somewhat effective. Seriously underpowered though - good thing today's neutral-tone VC papers are fast.
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    Re: Gradients on short edge of 4x5 Negs

    Nope; all I got was flow marks along the long edges of the sheet with the MOD54 due to the clamps that hold the film in place.
    I've sold the MOD54 some time ago because I didn't use it anymore...
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    Re: Can I Keep water in a JOBO?

    I've had my CPE2 for something like 5 years now. I think I drained it once. During prolonged periods of darkroom absence, the water level drops to perhaps 1/3 its original volume due to evaporation....
  30. Re: Potentially useful LEDs for darkroom/alt applications

    > Is there a unit available Used and or New that can do this for me and of course replacement bulbs and parts for the future.

    Bob, I'm a bit far away from you geographically, but what you want...
  31. Re: Top glass in negative carrier advantages vs disadvantages.

    It was apparently one of the options to use with the Laraneg carrier system. See here, particularly Gary Mulder's post: https://www.largeformatphotography.info/forum/archive/index.php/t-70332.html...
  32. Re: Top glass in negative carrier advantages vs disadvantages.

    > Are you sure it wasn't somebody else who made them?
    Yes. Durst L1200. Of course, I wouldn't know because I use the old-fashioned amateur 138 and don't have a background in the graphics arts...
  33. Re: Top glass in negative carrier advantages vs disadvantages.

    Scientifically, the best approach would be a glassless system that ensures perfect flatness and alignment in a dust-controlled environment (cleanroom). Glass in carriers is a compromise to ensure...
  34. Re: Top glass in negative carrier advantages vs disadvantages.

    So what if I manage to keep my negatives perfectly flat and aligned without using glass and without any risk of them popping? I get the benefits you speak of and the benefit of less risk of dust.
    ...
  35. Re: Top glass in negative carrier advantages vs disadvantages.

    2 additional surfaces that dust & dirt can adhere to per piece of glass, so 4 additional surfaces if bottom and top glass is used. But you know this perfectly well. So let's hear the real reason...
  36. Re: Top glass in negative carrier advantages vs disadvantages.

    No glass here. Too much hassle with dust, and I find it unnecessary for the size I print at. I.e., I cannot tell the difference between glass and no glass for the prints I make in terms of sharpness....
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    Re: How is Large Digital C-prints made?

    Drew, with all due respect, I'm Dutch, I live in The Netherlands, my professional career + PhD research have all been about high-tech supply chains & buyer-suppleir collaborations, the FujiFilm plant...
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    Re: How is Large Digital C-prints made?

    Hit hard - how, with what? I have no signs whatsoever that they were hit harder than the convenience store at the corner. Probably less hard, in fact.
    Furthermore, while supply of Kodak color...
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    Re: Banding in Negative

    Can you confirm the additional density is present in the negative? Does it extend towards the edge of the film, across the rebate?
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    Re: Digital Negative Printer Recommendation

    Same here. Have had a 4990 since it just entered the market; the positive side is that it has always worked. The negative side is that it does age in the sense of outgassing of materials used etc....
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