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Thread: Red light in Dark Room

  1. #1
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    Default Red light in Dark Room

    I have never been into a actualy dark room but from what i observed on TV or in the movies, i realised that they often use a red ligt bulb to illuminate the room.

    Why is that so?

    Kindly enlighten.
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  2. #2
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    Default Re: Red light in Dark Room

    Originally posted by Wolfgang
    I have never been into a actualy dark room but from what i observed on TV or in the movies, i realised that they often use a red ligt bulb to illuminate the room.

    Why is that so?

    Kindly enlighten.
    1stly, movies and tv shows are not accurate.

    The red light is also known as a safelight. It provides a light for the person to see what he's doing. Red light does not affect B&W paper, so it can be used like you see in the movies, you know, where the darkroom guy will expose the paper under an enlarger then soak the paper in a tank of developer and the image magically appears.

    But then, in TV/movies, you suddenly find that the output is colour. This is wrong, as in traditional colour printing in a traditional darkroom, you can't have any light as long as the paper is out. You have to work in complete darkness. In colour printing, you don't see the image appear. You load the paper into a sort of dev tank (light tight) and pour chemicals in.

    Regards
    CK

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    Ohhhh i see.

    I should know by now Hollywood more often than not exercises it's "artistic" licence.

    Thanks CK.
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  4. #4

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    Actually I was told by one of my friend during my first darkroom tutorial that the red light will affect the B&W photo paper provided u leave it exposed to the safelight for a lengthly period of time (i.e the few seconds of exposure during taking the paper out and then to the chemicals would not matter)...err...anybody can confirm this?

    Agreed on the total darkness required for coloured prints though.
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    Originally posted by BraveHart
    Actually I was told by one of my friend during my first darkroom tutorial that the red light will affect the B&W photo paper provided u leave it exposed to the safelight for a lengthly period of time (i.e the few seconds of exposure during taking the paper out and then to the chemicals would not matter)...err...anybody can confirm this?

    Agreed on the total darkness required for coloured prints though.
    Dunno man, I have not been to a darkroom for like 15 years. Of coz, if you leave it exposed to the safelight for very lengthy periods of time, I might get affected, but in normal cases, it should be okay.

    Regards
    CK

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    Originally posted by Wolfgang
    Ohhhh i see.

    I should know by now Hollywood more often than not exercises it's "artistic" licence.

    Thanks CK.
    Too much! If you've watched S1M0NE, you'll notice photogs shooting at close range with what look like 300-400mm lenses, and that at the kind of age the movie is in, those old magnesium explosion type flash bulbs are still in use.

    And transparent harddisks that slot into a CD-like motorized tray.....

    Regards
    CK

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    Default

    Originally posted by ckiang


    Too much! If you've watched S1M0NE, you'll notice photogs shooting at close range with what look like 300-400mm lenses, and that at the kind of age the movie is in, those old magnesium explosion type flash bulbs are still in use.

    And transparent harddisks that slot into a CD-like motorized tray.....

    Regards
    CK
    LOL... saw the trailer and noticed that.. kind of weird.. expecting people to believe.
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  8. #8

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    There are different kinds of safelight.
    There's orange ones and red ones, I've come across a green one as well but never had any opportunity to require its use.

    Dev tank for coloured papers are a norm, but if you're lucky, you'll have a colour paper processor that could dev continuous lengths of paper, similar to commercial film processors.

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    Originally posted by Scriabinesque
    There are different kinds of safelight.
    There's orange ones and red ones, I've come across a green one as well but never had any opportunity to require its use.

    Dev tank for coloured papers are a norm, but if you're lucky, you'll have a colour paper processor that could dev continuous lengths of paper, similar to commercial film processors.
    if i am not wrong the safelight (orange) is sodium light bulbs
    saw it at safra

  10. #10

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    Interesting question. In physics lecture, the lecturer said it was because red light is lower frequency and thus has lower energy than blue light. Hence it won't affect the negative-- doesn't have enough energy to break the bonds in the silver iodide, or something like that.

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    Originally posted by nicholas1986


    if i am not wrong the safelight (orange) is sodium light bulbs
    saw it at safra
    HUH? Safelights are all (ok, at least the red/yellow/orange ones I've seen) tungsten with a colour coating on the glass envelope.

    Sodium? You gotta be kidding. These are the ones use on streetlights.

    Regards
    CK

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    Originally posted by rumraisin
    Interesting question. In physics lecture, the lecturer said it was because red light is lower frequency and thus has lower energy than blue light. Hence it won't affect the negative-- doesn't have enough energy to break the bonds in the silver iodide, or something like that.
    It WILL affect film negative, but not the B&W paper. Do not try bulk loading film in a safelit room.

    Regards
    CK

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    Safelights come in a variety of colours,

    Red, Amber, Dark Green and Amber/Red being the most popular. Different colours for different film types. Most safelights are in the 10-20W range and use a coloured filter, either glass, gelatine or plastic which has a the desired filtration characteristics.

    You can tray develop colour prints, however it has to be done in total darkness and timing is critical thus most people use the so called 'daylight' saftey tank where the paper is loaded in to the tank in total darkness after exposure and then the sealed tank can be handled in normal light.

    Paper fogging (exposure) occurs with all safelights and the amount of time depends on the intensity of the safelight and it's distance from the paper. Most manufacturers recommend a minimum safe distance of 1m between the safelight and film. Normal practice is to perform a 'fog test' in the darkroom on a periodic basis. I test my darkrooms every 6 months to determine if the safelight filter requires replacing. A typical well designed darkroom should have a fog limit of around 4-5 minutes with paper on the enlarging easel or in the dev trays/tank loading area (for B/W).
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  14. #14

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    can we wear those infra glasses? those type used by the special task force. cool man.

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    can... but can only see ur hands? since the film is cool?
    maybe in a charlie chaplin movie the darkroom will be more authentic. they just hold the placard saying "Charlie develops his prints in a darkroom" since u can't see anything...
    Last edited by denizenx; 8th October 2002 at 03:32 AM.
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  16. #16
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    Originally posted by denizenx
    can... but can only see ur hands? since the film is cool?
    maybe in a charlie chaplin movie the darkroom will be more authentic. they just hold the placard saying "Charlie develops his prints in a darkroom" since u can't see anything...
    Vision in a well designed darkroom is excellent with the safelight(s) on, once your eyes are acclimatised which takes around 20 minutes or so.
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