Kodak Safelight Wattage

Discussion in 'Darkroom Equipment' started by Flotsam, Mar 4, 2005.

  1. Flotsam

    Flotsam Member

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    Does anyone know the maximum wattage that can be used in a Kodak 5.5" round safelight with a kodak OC filter?

    I have been using a 15 watt bulb and I can't believe that it is really supposed to be that dim
     
  2. Lee L

    Lee L Member

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    Kodak bullet style housing, right?

    IIRC, recommendations are 15W bounced off the ceiling, 7W direct at > 4 feet.

    Since I've started back in the darkroom, I'm using LEDs with variable voltage power supply, both red and yellow. I haven't done the testing yet, but prefer to keep it at low levels.

    See testing methods at:

    www.kodak.com/global/en/consumer/products/pdf/k4.pdf

    Lee
     
  3. Flotsam

    Flotsam Member

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    Might as well work in total darkness.

    One place that I worked had a sodium vapor safelight. You could read a newspaper without straining under that thing.
     
  4. Lee L

    Lee L Member

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    I also ran a darkroom with the Thomas sodium vapor safelights (in the late '80s). I found them to be way too far open when I took over the darkroom from the previous printer, and had to completely close the louvers, even for the typical 60 seconds for which I had paper exposed in that darkroom. I used a roller transport processor with lids, so the processing was dark. I've heard people say more recently that they are not nearly as "safe" as once thought.

    If you want a source for very bright red and yellow LEDs at reasonable prices, try superbrightleds.com. I'm using their lightbars, strings, and MR16 bulbs running off a 12VDC power supply with variable voltage, bounced off the ceiling. You could get them to go as bright as the Thomas, and they'd be cheaper, but they'd also probably fog at that level.

    Lee
     
  5. eric

    eric Member

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    That's interesting. I should look that up. I used to put velum paper inside them until I got it toned down.
     
  6. rjr

    rjr Member

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    Sodium Vapor has a big downside - the bulbs are expensive to replace and they´ll fail faster if you turn them on and off.

    If you are using an analyser of any type, LEDs are the way to go - last summer I had a friend to solder me a few banks of red and amber LEDs and a flashlight.

    I chose a mixture of red and amber ´cause it gave me a light tone suiting my taste and needs and it is safe with most papers.

    If you are going to DIY, check the specsheets of the LEDs. Papers made by Forte, Foma and Fotokemika usually demand red light, you are safe with LEDs emmitting light at 660nm. Most papers made by Agfa, Ilford and Kodak are safe with yellow/amber LEDs of 595nm.

    At the moment I am running three banks of approx 60LEDs (each 5000mcd) in total in a darkroom of 3,5x5m and I can read any paper, any book and table in there, the mixed light is safe for my Foma papers for 15min at each distance - haven´t run the test any longer, thats good enough.

    This setup plus a smallish LED flashlight cost me not more that 15EUR for the material.

    Plain and simple: It´s great.

    If you don´t wan´t to DIY, you can buy LED spots at many warehouses. These screw in E27 standard sockets and according to the spreadsheet the red type emits at 660nm. These are slightly more costly, 10-15EUR/"bulb", and a bit dimmer that the ultrabright LEDs.
     
  7. David Brown

    David Brown Subscriber

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    15 watt is the recommended. You could try a 25 watt and do the standard safelight test.

    What color are your darkroom walls?

    David
     
  8. Flotsam

    Flotsam Member

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    I think that I'll stick a clear 15w bulb in it just to try to milk a little more light out of it and try to find a cheap 5x7 Premier to fill out the area a bit.

    I thought that an expensive Kodak Glass OC filter would be pure enough to handle a little more brightness than some off-brand piece of amber colored plastic.
     
  9. rbarker

    rbarker Member

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    I think I'd be cautious about putting an incandescent bulb higher than a 15W bulb in the bullet enclosure - might produce more heat than either the enclosure or the filter can handle.
     
  10. eric

    eric Member

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    This is interesting. I didn't know you can get screw in LED light "bulbs" that will fit a regular socket. Can youget these at Home Depot or Lowes?

    I have a LED small pocket flashlight that my son plays with. Few months now on the same 1 AA battery.
     
  11. Flotsam

    Flotsam Member

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    I wonder what would happen if I put one of those twisted flourescent incandesent light bulb replacers in there? If you used the lowest "wattage" and then ND'd it down with vellum inside the filter until it passed a "safe" test.
    Maybe pick up some more brightness without the heat.
    Just thinking.
     
  12. Lee L

    Lee L Member

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    I wouldn't try either a higher wattage or twisted flourescent lamp in an enclosed Kodak bullet safelight. Brighter incandescent lamps will get too hot, the flourescents aren't typically designed for enclosed (and therefore hotter) fixtures, and the safelight filter will fade a lot faster if you overlight it. These safelight fixtures are completely unventilated, and run hotter than a typical light fixture. You should believe that Kodak has tested this stuff and knows the limits.

    I've never seen an LED spot in a home improvement store in the US. Most Americans think "brighter is better" and pay much less for electricity than Europeans, and manufacturers won't try to sell them LEDs as floodlights. We don't conserve water or electricity like the Europeans do. That being said, superbrightleds.com has Edison based 110VAC LED lamps in 630nm red and 590nm amber, but these are very bright and the circuit used to run them on AC makes them not significantly dimmable. See: http://superbrightleds.com/MR16_specs.htm for the Edison based and MR-16 alternatives.

    The superbrightleds MR-16 12V lamps and 12V "light bars" are fully dimmable with a 12VDC or lower power source and also come in the same amber and red that you could match to the paper you use. They also sell ceramic sockets for the MR-16 lamps that are a cinch to wire; strip two small guage wire ends and shove them into two holes. The other two ends go to your power supply. Prices are very good, but at the draw these LEDs take, you don't need the higher priced power supplies at superbrightleds. I usually get stuff from them about 2 days after I order, and they don't kill you with shipping or minimum orders.

    To power and dim my 12VDC darkroom safelight LEDs, I use this:
    http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=120-536
    I got mine for about $4 each on sale, but at $15, they do nicely up to 2 amps, and have a built in 6 position voltage switch that can dim the LEDs. The LED arrays we're talking about draw milliamps, so you can run way more than you need off one of these supplies. Even most 12V "wall wart" ACto DC power adapters for portable electronics will run an LED light bar or MR-16, or two.

    Lee

    Just noticed that the power supply I recommended is out of stock and due back in May 1. Sorry about that. But it is a good option for this use.
     
    Last edited by a moderator: Mar 5, 2005
  13. 127

    127 Member

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    I've got a couple of beehives that I aquired with 6B filters in - designed for X-ray work apparantly. They had 25 watt bulbs in so, that's what I replaced them with. Even so they're VERY dim. They're mounted about 2 feet from the work top, but it still looks pitch dark in there. A third behive has a more conventional filter in, but that's almost as dim.

    According to the spec, they're too close, too powerfull, and the wrong sort anyway! However as they're set up they're still FAR FAR less bright than the old cheapo safelight I used before. Occasionally I worry about it, but most of the time I think it's not a problem.

    I think kodak's spec is conservative. If I put 15W bulbs in, and bounced them off the roof I'd be in total darkness.

    The 25W's don't seem to be a problem. No they're not vented, but the cases are metal, and get moderatly hot, which allows the heat to disipate. Besides, my darkroom needs all the heat sources it can get!

    Ian
     
  14. Max Power

    Max Power Member

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    Neal,
    I've got those fluorescent 'bulbs' all over my house. I use them for two reasons. Firstly because they throw better equivalent light to an incandescent at lower wattage. Secondly because they are much much cooler. Apparently, though, these bulbs don't last as long as they ought to if you keep turning them on and off. I have them in some places where they are constantly being switched on and off and they are fine, but who knows.

    You might have to check for clearance, though, 'cause the fluorescent spirals are quite a bit bigger than the little 15W bulbs in the safelight.

    BTW, I find Kodak's instructions on the safelight (I have the same one) very conservative. My darkroom is 6x6 and I had no choice but to place the safelight at a height of about 7ft and pointing straight out into my workspace. I did a paper test and even after 8 minutes there was absolutely nil fogging.

    Hope this helps,
    Kent
     
  15. Claire Senft

    Claire Senft Member

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    A matter of choice.

    Although I use an old safelight that I received with a 7 watt bulb behind o a
    green filter for film latensification with a bulb dimmer set fairly low i do not otherwise use a safelight. I want to make certain that In the future I can repeat my printing of a negative from notes. So, I adjust my temperature before exposing the paper and process for the full two minutes and after fixing turn on the room lights. The print inspection light used with a bulb dimmer that is set to the light level that will be used to display the print. It is not hard to do it in the dark and I am not influenced by the appearance of the print as it develops. There are trade offs involved of course but I find it to work very nicely for me. It is cheap..no investment...no energy usage...extremely reliable...no safelight fog. I have several acquaintances that save me their burned out bulbs in case the total darkness becomes to oppressive..although the difference between total darkness and the burned out bulbs is very subtle, I find it to be emotionally satisfying to be able to make these distinctive choices and to fine tune my darkness.
     
  16. Flotsam

    Flotsam Member

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    That is a good idea considering the ridiculous prices of new darkbulbs from photographic suppliers.
     
  17. rjr

    rjr Member

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    LED spots

    Most likely - you can get these in the german equivalent of RadioShack - Conrad.

    It´s the small standard bulb socket, used for reading lights etc... it comes with a DC/AC converter built in, so you just have to screw them into the socket and turn on the light. Power consumption is quite low, the light emitted is slightly less than that of a 25W bulb in a Beehive with Kodak Wratten Red-filter.

    For those who don´t know where to hold the soldering iron (NOT the hot one!), thats a good chance to illuminate the darkroom...
     
  18. Dr.Kollig

    Dr.Kollig Member

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    I used to work with an old metal safelight with Agfa X-Ray filter and it was as dim as yours. These days I use one LED unit from Kaiser, bought in 2001 and the screw in LED E27/220 V. Consider some of these LED units, will make live a loooot easier.

    BTW, what camera are using to expose the 127 film? My Baby Rolleiflex (1957-63) is mostly on display.

    I use hot tea to warm up in the red light darkness district.

    Wolfram
     
  19. 127

    127 Member

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    I've got way too many... (check my website!). The main shooters are a Gray Baby Rollei, and a Komaflex. I'm also hoping to get my Exacta back into a working state real soon...

    Ian
     
  20. Nick Zentena

    Nick Zentena Member

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    15watt flourcent is about equal to I think a 60watt normal bulb. It's a lot of light and maybe a lot of fog. Why do you want to read a newspaper in the darkroom? Mine is pretty close to dark. Red safelight for B&W. Total darkness for colour. What would I gain with a brighter safelight?

    BTW I think the 5x7 premier is only 15 watts to.
     
  21. Flotsam

    Flotsam Member

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    I like to be able to locate my burning and dodging tools, grain focuser, stereo remote control and beer while printing. I also like to watch my print come up in the tray. Does anyone else pull a print out of the developer and breathe on it to increase activity in selected areas?