Switch to English Language Passer en langue franšaise Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,556   Posts: 1,573,158   Online: 772
      
Page 2 of 2 FirstFirst 12
Results 11 to 18 of 18
  1. #11

    Join Date
    Jun 2004
    Shooter
    Medium Format
    Posts
    396
    Hmm...
    I havn't used my densitometer for some time now. (Testing film after film after film for various developers just became too much...) But now I have found a very good use for it again.
    Thanks guys and have a happy new year.

    //Bj÷rn

  2. #12

    Join Date
    Nov 2005
    Location
    Cheshire UK
    Shooter
    Medium Format
    Posts
    1,905
    Dear All,

    It is highly dependant on the amount of use ( exposure to light ) and care of the filters, we always were told that they had a 5 to 8 year life and to change them for optimal performance after approx 5 years.

    Simon. ILFORD Photo / HARMAN technology Limited.

  3. #13
    PeterB's Avatar
    Join Date
    Apr 2005
    Location
    Sydney, Australia.
    Shooter
    Medium Format
    Posts
    600
    Thanks Simon ! My new ones are arriving tomorrow.

    I have thought of an easy way to determine when the filters being fading. When I first take the new ones out of their packet, I take a set of photos of them on my light box as I did here, then every year I check to see how subsequent photos compare. With my dig*t*l camera I set it to do a custom white balance on the light box - this way it should take into account any changes to the light box's spectral composition over time. Visual comparison or even numeric comparison of the RGB values in an image editor will tell me plenty. Voila a poor man's colour densitometer !

    regards
    Peter

  4. #14
    Martin Aislabie's Avatar
    Join Date
    Nov 2007
    Location
    Stratford-upon-Avon, England
    Shooter
    4x5 Format
    Posts
    1,413
    Peter, it might not be quite so simple

    I found my old MG Filters flared a bit too

    So you might need to come up with a cunning flare test too

    Martin

  5. #15
    PeterB's Avatar
    Join Date
    Apr 2005
    Location
    Sydney, Australia.
    Shooter
    Medium Format
    Posts
    600
    I'm using my filters above the lense so flare shouldn't be a problem. Martin can you explain what changes about a MG filter over time to cause it to flare ?
    rgds
    Peter

  6. #16
    Martin Aislabie's Avatar
    Join Date
    Nov 2007
    Location
    Stratford-upon-Avon, England
    Shooter
    4x5 Format
    Posts
    1,413
    Hi Peter, I'm just guessing about the decay mechanism

    I suspect the surface of the filter (gelatine?) starts to microscopicaly flake and becomes uneven - so would scatter light

    My old bellow the lens filter set had a slightly milky appearance when compared to the new ones

    Because the decay is so gradual its a bit hard to notice - only by holding the old & new filters next to each other were the differences apparent

    Also looking at the filter surface at an oblique angle - the new ones were mirror like & shinny but the old ones were more of a semi-matt finish

    Sorry, its the best I can do

    Martin

  7. #17
    scinysnaps's Avatar
    Join Date
    Sep 2008
    Shooter
    Medium Format
    Posts
    55
    Peter,
    Just got my new filters today..
    The #4 was faded compared to the new set,so hopefully the problem is solved!

  8. #18
    PeterB's Avatar
    Join Date
    Apr 2005
    Location
    Sydney, Australia.
    Shooter
    Medium Format
    Posts
    600
    Yeah, mine arrived yesterday too and my old#4 was really faded. In fact there were sufficient differences between the other numbers too to make me think I had the older style referred to here by Ilford which are "likely to give poor or unpredictable results" anyway !

    Soon I'll post photos comparing the two sets.

    rgds
    Peter

Page 2 of 2 FirstFirst 12


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  Ś   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin