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  1. #21
    Ektagraphic's Avatar
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    Do enlarger bulbs typically have a short life? Have many types already gone out of production? For my enlargers with a standard edison base, I have thought about trying an LED bulb to see what happens.
    Helping to save analog photography one exposure at a time

  2. #22
    L Gebhardt's Avatar
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    Quote Originally Posted by Ektagraphic View Post
    Do enlarger bulbs typically have a short life? Have many types already gone out of production? For my enlargers with a standard edison base, I have thought about trying an LED bulb to see what happens.
    The 211 and 212 bulbs which are common have a 100 to 200 hour rated life, depending on the manufacturer. The Ushio PH213 has a rated life of 3 hours. But given the cost of these bulbs I would also be inclined to just stock up with 10 or more of them and then buy a new one when one burns out.

    The Durst bulbs are out of production for the 138S. I don't know how long they bulbs are rated for, but at the cost of finding replacements I want to extend their life as much as possible.

    The LED bulbs are all over the place in terms of quality. Also some of them glow after you turn them off. I have noticed this with the Philips bulbs that have the yellow panels, which contain phosphors that are activated by the UV in the LEDs. I have had very good luck using raw LEDs (with the appropriate power supply), but the few bulbs I put in were not particularly successful. But I only tried the ones I had around the house.

  3. #23
    polyglot's Avatar
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    This is so far into false economy it's hilarious. Consider a few things:
    - a bulb lasts a couple years of heavy use and costs $5 to $20, compared to the $2000+ you'll probably spend on film, paper and chemicals to do that much printing
    - running at lower voltage lowers the temperature, which makes the light redder, which means lower contrast from VC paper. Once you've corrected the contrast with magenta filtration, your exposure times will be longer - probably longer than is necessary to make up for the "increased" bulb life
    - bulb life in an enlarger is related mostly to number of power cycles (due to inrush current at startup), not total burn duration. So you're optimising something that isn't even the dominant factor for bulb life.

    If you want longer bulb life (why? it's an irrelevant cost compared to film, paper and chemistry) then put a mechanical shutter on your enlarger and switch that instead of the bulb. Or do LED exposure.

    Or seriously, quit worrying about irrelevancies. This is like worrying about brake-light life on your car.

  4. #24
    Jim Jones's Avatar
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    I power the incandescent lamp in an enlarger through a dimmer. Framing and focusing can be done with the lamp dimmed, and the exposure made at full power. Dimming an incandescent lamp does prolong life, but the lamp still produces nearly as much heat and is inefficient in utilizing power. Long ago, when a 16mm movie projectionist in a remote Navy installation, reducing voltage to the projector by 10% through a stepdown autoformer prolonged lamp life by a factor of several times. I once used 40 and 60 Watt lamps in series for greatly extended lamp life (years of continuous use). The 60 Watt lamp barely glowed. This is practical only where lamp life is much more important than efficiency. The system has been replaced with a LED lamp which produces much better light and consumes much less energy. The high cost of the LED is no more than a few months of the power consumed by the series lamps.

  5. #25
    Nicholas Lindan's Avatar
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    There is a common misconception that turn-on cycles will decrease the life of an incandescent lamp, this is not the case.

    True, most lamps fail when turned on - but at that point they are at the end of their life. If the lamp didn't fail when it was turned on it would have failed in the next few hours in any case.

    Only total operating hours have any real effect on lamp life. As a lamp operates the tungsten in its filament changes from a malleable form to a crystalline form - and this is what sets the end-of-life point for the lamp. This change happens gradually as the lamp burns.

    Placing an inductor in series with a lamp is a very good way to really, really shorten the life of your timer.

    Lamp operating points are optimum - there is nothing to be gained by changing the operating voltage. The only time this can make sense (by using 135V lamps) is when the lamp is an inaccessible place - like a high ceiling - and you need to rent a lift to change the lamp (a better solution is to shoot the architect who put the lamps up there and plaster over the luminaire holes).
    DARKROOM AUTOMATION
    f-Stop Timers - Enlarging Meters
    http://www.darkroomautomation.com/da-main.htm

  6. #26

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    I have a couple of dimmers in my house that are designed to turn on the lights with a short but noticeable gradual increase instead of instant full on. It seems a good idea to me, given that the resistance of the incandescent globe is much less when cold that when at operating temperature.

    I understand that an inductor in series with a globe can cause a surge: maybe a snubber circuit at the timer would alieviate the problem.

  7. #27

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    Good voltage regulation is important, and proper burn position and ventilation. But the number one factor in bulb longevity, in my experience,
    is to buy good bulbs in the first place. You get what you pay for. Those cheapo bargain bulbs made in China are horrible for longevity.

  8. #28

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    I really got a kick out of this post... Increase the life of a bulb that normally lasts a good 15 years anyway is rediculous.

    Me 4x5 beseler has been burning bright for the past 30 years and i do use it for at least 25 hours per week. I do have 3 extra bulbs as back up i bought several years ago thinking these bulbs will become a problem to find once digital gets a foot hold.... Wrong!

    So perhaps a better solution might be purchasing extras while they are available n cheap.... Base your needs on your average life of the bulb and your expected life span.

    Hahahahaha.... Oh btw kids... LEDs will make a good substitute if not a better solution as well as upgrading your enlarger with a technology with a much better longevity track record.

    Oh i also bought 2 extra cold lamp bulbs n a spare head i will ever use in my life time... Yeah my garage is full of spares... I wish i could find a spare heart, kidneys, liver, knees... Etc instead of all this crap my kids will toss in the garbage when i'm dead.
    Anyone can make a Digital print, but only a photographer can make a photograph.

  9. #29
    L Gebhardt's Avatar
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    Quote Originally Posted by paul ron View Post
    I really got a kick out of this post... Increase the life of a bulb that normally lasts a good 15 years anyway is rediculous.

    Me 4x5 beseler has been burning bright for the past 30 years and i do use it for at least 25 hours per week. I do have 3 extra bulbs as back up i bought several years ago thinking these bulbs will become a problem to find once digital gets a foot hold.... Wrong!

    So perhaps a better solution might be purchasing extras while they are available n cheap.... Base your needs on your average life of the bulb and your expected life span.

    Hahahahaha.... Oh btw kids... LEDs will make a good substitute if not a better solution as well as upgrading your enlarger with a technology with a much better longevity track record.

    Oh i also bought 2 extra cold lamp bulbs n a spare head i will ever use in my life time... Yeah my garage is full of spares... I wish i could find a spare heart, kidneys, liver, knees... Etc instead of all this crap my kids will toss in the garbage when i'm dead.
    That's a great plan if bulbs are still available for your enlarger. But there is at least one system, the Durst 138S that I have, where the bulbs are no longer available. It was in this context that I posted the idea to extend the life of the few existing bulbs. Given that new bulbs go for over a $100 it makes sense to me to save the few that you can find. I never intended people to buy a variac to save a bulb that you can still but for $5.

    For the Durst you have a few options. Durst Pro sells a replacement lamp system for over $1000. You can scour ebay and try to buy the official bulbs if they show up (about two a year it seems). You can use the PH303 bulbs that work pretty well. No idea how long they will be available, so buy a few spares. They are also 500 watts, so the variac can help reduce the brightness. You can buy a kit from Glenview that repurposes an existing bulb. One came with my latest enlarger, and I can confirm it works fairly well. Or you can do what I finally did and build an LED system.

    So as a couple of you have pointed out it's a bit silly to worry about for most cases, but I'm sure some people will find the ability to extend the life of rare bulb to be valuable. Even if you don't intend to implement the idea, I still think it's interesting how a small change in voltage can change the expected life of a lamp.

  10. #30

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    And no matter how much you extend the life of an already old extinct bulb, it will inevetably die and an alternative will have to be saught.... Or perhaps you will be dead by then and your kids will nurry you and your anciant equipment in the same box.

    So a better solution is to adapt now before it becomes a problem n tjis will save more brain cells in the long term.

    Sill a helarious thread... Oh btw my front door light has a 220V bulb running on 110V... I put it in 38 years ago n i have it on every night from dusk to dawn... So yeah your technique works fir some things but still very impractical for this application where color temp n other variables only complicate an already complicated system...

    Adapt or dump the extinct for a new old enlarger... They are dirt cheap these days n even found by the curb on trash night.

    A varey entertaining thread for sure.
    Anyone can make a Digital print, but only a photographer can make a photograph.

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