Kodak Wratten Gelatin filter no.12 ??????

Discussion in 'Kodak' started by simon3000, Dec 1, 2004.

  1. simon3000

    simon3000 Guest

    Dear All,

    I am a medical doctor looking to purchase a Kodak Wratten Gelatin
    filter Number 12 for use in assessment of patients with dry eye using
    fluorescein tear staining.

    I have looked in a number of local photography shops, on ebay, the
    kodak website and various other websites but have been unable to find
    out where i can buy one.

    Can any of you tell me where I can buy one in the UK (preferably via a
    website or somewhere that will post it to me)??

    Thanks for any help

    Simon
     
    simon3000, Dec 1, 2004
    #1
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  2. This should be available anywhere. It is just a yellow (minus blue)
    filter, a little wider attenuation band than the #6, #8, #9, but not as
    wide as a #15 or #16.

    Calumet, in Chicago, certainly have them:

    http://www.calumetphoto.com/ctl?PAG...;130;Unmounted+-+Polyester,+Gelatin;239;Kodak

    I am sure they would be delighted to sell you one and ship it to you.

    However, I am sure Kodak in England should be abble to supply you one more
    expeditiously. Why not call them and ask where your nearest dealer is that
    would supply you with such a filter in retail quantity?
     
    Jean-David Beyer, Dec 1, 2004
    #2
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  3. simon3000

    Nick Zentena Guest


    Does it need to be a Kodak? If you ask Lee they might be able to give you
    some advice.

    http://www.leefilters.com/CP.asp?PageID=119


    If it needs to be Kodak then you can always get it from:

    http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=26344&is=REG


    I'd be suprised if any good pro type shop in the UK couldn't order it for you.

    Nick
     
    Nick Zentena, Dec 1, 2004
    #3
  4. Should be a standard item. Try B&H in the US.

    Are you sure you want a gel filter? They are awfully fragile. A glass
    photographic filter may be a better choice. A #12 is a 'deep yellow',
    sort of light orangish, and any camera supplier worth its salt should
    have them. You don't need 'Wratten #12', any deep yellow will work.
    Snappy-Snaps won't have it.

    Also try LEE (&other) theatrical filters. In the US they hand out
    little sampler books of 2x3" filters for a nominal fee (free if you
    are actually in the theater trade).

    Not to belabor the obvious, but have you tried a medical supplier catering
    to opthamologists and optometrists.
     
    Nicholas O. Lindan, Dec 1, 2004
    #4
  5. simon3000

    simon3000 Guest

    thanks for the info everyone.

    I have no technical knowledge - i wanted a Kodak Wratten 12 because it
    seems to be the one that is always recommended in the field of dry eye
    - i believe this is because it absorbs the exact wavelengths emitted
    by fluorescein dye
    - are there other filters that would absorb the exact same wavelengths
    yet be sturdier?

    Thanks

    Simon
     
    simon3000, Dec 1, 2004
    #5
  6. simon3000

    Nick Zentena Guest


    How are you going to use it? Hold it in your hand? Mount it? You can get
    glass #12. That should last almost forever if you don't step on it. Or you
    could get a sheet of filter material from Lee. Tell them the wavelengths you
    need to absorb. That's assuming you can live with the quality of lighting
    filters. The stuff is fairly cheap. Letting you treat it like a throw away.

    Lee doesn't have much info on it's website but you could look at the Rosco
    one.

    http://www.rosco.com/us/filters/roscolux.asp#SPECIFICATIONS

    Pick the filter that provides what you need. Stuff can be cut to size.

    Nick
     
    Nick Zentena, Dec 1, 2004
    #6
  7. You should be able to obtain glass filters with approximately the same
    specifications. The Wrattan filters spectrophotometric curves are in
    Kodak's publication B-3. The other manufacturers should also be able to
    give you the curves for their filters.
     
    Jean-David Beyer, Dec 1, 2004
    #7
  8. simon3000

    simon3000 Guest

    i couldn't find a wratten 12 filter on the calumet website - they only
    seem to sell one particular Kodak Wratten filter which is not a number
    12

    Simon
     
    simon3000, Dec 1, 2004
    #8
  9. simon3000

    Peter Guest

    Calumet operate in the UK too.

    Peter
     
    Peter, Dec 1, 2004
    #9
  10. Would an equivalent glass filter do? It is a very common yellow filter, No.
    12, but usually made of glass nowadays. The transmission curve is very much
    the same.
     
    Michael A. Covington, Dec 2, 2004
    #10
  11. Ah! Everybody uses Wratten numbers (except for Nikon, which uses Hoya
    numbers; on the other hand Hoya usually uses Wratten numbers)... So a No. 12
    yellow filter, of any brand, will be a very close substitute for what you
    originally specified.
     
    Michael A. Covington, Dec 2, 2004
    #11
  12. simon3000

    friend® Guest

    good advice. contact Lee and ask for a sampler. it contains all their
    filters in size 2.5 by 5 cm (around). Then experiment. the set has
    spectral graphs printed on separating sheets.


    On Wed, 1 Dec 2004 10:39:16 -0500, Nick Zentena

    *> Dear All,
    *>
    *> I am a medical doctor looking to purchase a Kodak Wratten Gelatin
    *> filter Number 12 for use in assessment of patients with dry eye using
    *> fluorescein tear staining.
    *>
    *> I have looked in a number of local photography shops, on ebay, the
    *> kodak website and various other websites but have been unable to find
    *> out where i can buy one.
    *>
    *> Can any of you tell me where I can buy one in the UK (preferably via a
    *> website or somewhere that will post it to me)??
    *>
    *
    *
    * Does it need to be a Kodak? If you ask Lee they might be able to give you
    *some advice.
    *
    *http://www.leefilters.com/CP.asp?PageID=119
    *
    *
    *If it needs to be Kodak then you can always get it from:
    *
    *http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=26344&is=REG
    *
    *
    *I'd be suprised if any good pro type shop in the UK couldn't order it for you.
    *
    *Nick
     
    friend®, Dec 2, 2004
    #12
  13. Kodak still makes Wratten gelatin filters, they are sold
    by the motion picture division in sizes from 3x3 inches to
    14x18 inches. The No.12 is still listed. You may have to buy
    this directly from Kodak. Try their UK sales agency:

    UNITED KINGDOM
    Entertainment Imaging
    Kodak Ltd. Kodak House
    P.O. Box 66, Station Road
    Hemel Hempstead
    Herts HP1 1JU England
    Phone: +44 1442 845945
    Fax: +44 1442 844458
     
    Richard Knoppow, Dec 2, 2004
    #13
  14. simon3000

    Nick Zentena Guest

    Or B&W. Does Heliopan use Wratten numbers?

    Nick
     
    Nick Zentena, Dec 2, 2004
    #14
  15. simon3000

    Tom Phillips Guest

    Wratten Yellow No. 12 is nearly identical to the No. 15 yellow,
    but the 15 has very slightly stronger absorption at 500+nm. If
    these were being used for photographic purposes there would be
    virtually no difference. But with strict scientific use there
    may be a difference. The 12 is a minus blue filter and allows
    slightly more green-blue wavelengths to pass at 500-600nm.

    Calumet USA does have it under Camera Accessories/filters
    or do a Calumet search using wratten filters.

    Tiffen may also have it in glass.
     
    Tom Phillips, Dec 2, 2004
    #15
  16. In fact, I don't think so. Times have changed while I wasn't looking!
    There should be an easy to identify equivalent to the No. 12 in these other
    product lines, by comparing curves.
     
    Michael A. Covington, Dec 2, 2004
    #16
  17. ??Lonely Boy??, Dec 2, 2004
    #17
  18. And at what prices ...

    14x18 $863.95
    6x6 151.95
    3x3 23.95

    I thought I would replace a missing polycontrast filter ...
    But I saved money and bought a dichoric head instead.

    Both Wratten and Rosco publish transmission curves on the
    web.

    http://www.rosco.com/us/filters/roscolux.asp#Color

    Not only does rosco have a #12, they have a #9, 10 and 11.

    Yes, I know the numbers are not _supposed_ to be the same etc.,
    but:

    http://www.geocities.com/thombell/filters/wf12.gif

    Use the Wratten table, not the chart when comparing for
    visual effect. The rosco chart is readable.

    Interesting the yellows have a parasitic pass band in the UV, I wonder
    if the OP's application made use of this pass band to excite
    flourescein. Kodak only has ~1.5% transmittance Vs 35% in the
    UV.

    Most likely both filters use the same dye and would have the
    same curves if measured in the same equipment by the same
    personnel.

    Now the kicker:

    Roscolux #12 20" x 24" sheet $5.65

    That's 0.27 per square inch for Wratten, Vs .012 for rosco.
    If Kodak is cutting up rosco gels they are doing it with
    a 2250% mark up.
     
    Nicholas O. Lindan, Dec 2, 2004
    #18
  19. simon3000

    Nick Zentena Guest


    But those are lighting filters. Are they good enough for use in front of
    th lens? I've used them for spilt printing but that's between the light
    source and the negative.

    Nick
     
    Nick Zentena, Dec 2, 2004
    #19
  20. simon3000

    RWatson767 Guest

    Simon3000
    I am a medical doctor looking to purchase a Kodak Wratten Gelatin filter Number
    12 for use in assessment of patients with dry eye using fluorescein tear
    staining.

    What size? There are or were several sizes. Some round ones also.

    Bob AZ
     
    RWatson767, Dec 2, 2004
    #20
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