So, what excactly is the safe filter?

Discussion in 'Enlarging' started by Helinophoto, Jan 31, 2012.

  1. Helinophoto

    Helinophoto Member

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    Embarrassingly basic but....

    Just wondering. :smile:

    The safe filter that you have below your lens on your enlarger, is that the same kind of thing as, say a Hoya #25 red filter...?

    I do have a (optically broken) #25 filter lying around and I kind of need a replacement for my existing safe filter on my enlarger (it's modified for medium format, so the safe filter doesn't cover the 35mm light totally, because that lens is further away from the filter itself).

    Can I use my #25 filter as a safe filter for my enlarger I wonder...?

    Can you buy this filter in sheets or parts somewhere? (what are the requirements for such a filter?).
     
    Last edited by a moderator: Jan 31, 2012
  2. polyglot

    polyglot Member

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    It's probably rubylith; if you want to replace it then that's what I'd use (it comes in sheets and is very very cheap). Light filtered by rubylith tends to be pretty paper-safe, especially if it came from an incandescent bulb.
     
  3. ic-racer

    ic-racer Member

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    I have used Rosco #27 Medium Red. For example, this is what I cover my flashlight with. I also have it over the bulbs that illuminate the color wheels on my enlarger head. My local shop carries this color, but not Rubylith. Your #25 filter should work also.

    Why are enlarger safe filters red? Because this makes them safe for nearly all B&W papers.
    Why are safelights frequently orange? The orange light looks brighter to the human eye, but not all papers are safe to an orange light.
     
  4. degruyl

    degruyl Member

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    I found that switching to red filters on my safelights made seeing in my darkroom easier. Except when trying to see red china marker, of course.

    My impression is that OC (amber) safelights are apparently brighter but I can see finer details under red. I suspect it has to do with the color receptors in my eyes (and I don't have a clue whether I am normal in this regard).
     
  5. Helinophoto

    Helinophoto Member

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    Thanks, I found some rubylith on eBay, ordered myself a sheet (was cheap =) ).

    Good to know the #25 can be used, right now it's a bit critical not to be able to study the negative and/or fine-tune focus ^^
     
  6. polyglot

    polyglot Member

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    You know you can just focus on a bit of dud paper using white light? Using a focusing aid? You don't actually really need the safe filter IMHO. Red light is kind of bad for focusing because the wavelength is so long (more diffraction) and your eyes don't resolve it nearly as accurately as green.
     
  7. Newt_on_Swings

    Newt_on_Swings Member

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    Yup, best not to take paper out until all is aligned, cropped, and focused on the back of a scrap paper of the same thickness, same aperture, and same color multigrade filter you intend to use. Less time paper is out less chance of fog.

    The only time I use the red filter is when I need to double check my aim for where to start a burn, or for combination printing of 2 negatives.
     
  8. Doremus Scudder

    Doremus Scudder Member

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    FWIW, I never use my red filter when enlarging. I focus on a scrap sheet and practice dodging and burning moves if they are tricky before getting a real sheet of paper out of the package.

    Focusing under white light, with the lens wide open is a lot easier and more reliable.

    Best,

    Doremus
     
  9. RalphLambrecht

    RalphLambrecht Subscriber

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    normsl