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What is the effective film speed of Ilford Multigrade paper?

Discussion in 'Everything Film' started by alindsay, Nov 13, 2013.

  1. alindsay

    alindsay Well-Known Member

    The datasheet cites a speed of ISO P500, which is clearly a different ISO standard from that of film.

    I have it in the back of my mind that it's something like ISO 4-6, but I wonder if anyone can confirm this. I plan to use some Multigrade paper in a pinhole camera, though the camera instructions (it's the Ilford Obscura) don't give any guidance on this. It'd also be good if anyone can give me advice on how to approach the problem of reciprocity failure with such paper.

    Many thanks.
     
  2. Roger Hicks

    Roger Hicks Well-Known Member

    About 3-6 in film terms. Yes, you're right, paper ISO is completely different. Don't worry about reciprocity, though: remember, paper is designed for long exposures.

    Cheers,

    R.
     
  3. alindsay

    alindsay Well-Known Member

    Many thanks, that's perfect.

    Oooooh, here cometh today's slap-forehead moment. Of course, of course!
     
  4. taxor

    taxor Well-Known Member

    As per darkroom use, just do a couple of test strips (exposures)
     
  5. gray1720

    gray1720 Well-Known Member

    This was metered at ISO 6, with a grade 2 1/2 or a 3 contrast filter over the lens (elderly Kodak folder rather than a pinhole):

    http://s726.photobucket.com/user/gray1721/media/No3.jpg.html
    (changed to a link, as I think it's over 800 pixies tall)


    So if you work on around ISO 6 you probably won't go far wrong.

    Adrian
     
  6. 0lybacker

    0lybacker In the Stop Bath

    Hi Roger,

    Not sure that's right. IIRC what I was taught, it's just that the limits are so far away from normal use for normal print sizes we do not notice it. In contrast (NPI :rolleyes::D) film reciprocity can kick in - depending on film make/type/developer - at quite quick long exposures, such as 1/8 or 1/4 sec.

    Cheers,
    Oly
     
  7. Zou

    Zou Well-Known Member

    I've used it in large format pinhole cameras rated as ISO 6 which was fine. The issue when being used photographically is long exposure (as within a pinhole camera due to very small apertures) leads to excessive contrast and a lack of midtones. If using with a lens this would not really be such an issue.
     
  8. alindsay

    alindsay Well-Known Member

    I've just done a quick meter reading outside my window, and with the meter set to ISO 100 it's about 1/60 at f/11. By just doubling all the way down to the approximately f/250 of the pinhole and an ISO 6 rating, that seems to work out at about a minute's exposure. Does that sound about the right order?

    (I do have a set of Multigrade filters, but they're the old style, from many years ago when MG first came out, and I think the filtration system changed since then.)
     
  9. Roger Hicks

    Roger Hicks Well-Known Member

    Sounds about right.

    MG filters changed little if at all. At least, I assume you don't mean "First came out" in 1940...

    Cheers,

    R.
     
  10. alindsay

    alindsay Well-Known Member

    Too early even for me! I hadn't realised MG was that old. Just goes to show that not everything that's high-tech was invented last Tuesday.

    I'm racking my brains (well, the duty neurone) to recall when I started using MG paper, for I remember buying the below-the-lens carrier thing for my old Gnome enlarger (a mere sixteen guineas in 1968), probably very late seventies, when resin-coated MG appeared. There was a MG II a few years later which had a different filter set, about a dozen I recall, where my set just had seven, and I couldn't get particularly contrasty prints from them.
     

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