Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,840   Posts: 1,582,587   Online: 988
      
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 22
  1. #11
    Greg Davis's Avatar
    Join Date
    Feb 2004
    Location
    Crestview Hills, KY
    Shooter
    8x10 Format
    Posts
    1,950
    Quote Originally Posted by RalphLambrecht View Post
    Greg's tests verifies my and other people's experience. Love to see the prints!
    Ralph, you wanted to see my prints, so here they are. I put the same filters together for easy comparison and labeled each print with the grade and light source. In case it's too small in the picture, diffusion is on the left, condenser on the right. The prints may have more or less contrast than the screen image since your monitor may not be calibrated like mine, but it will give you a good sense of the relationships.
    Attached Thumbnails Attached Thumbnails 01.jpg   02.jpg   03.jpg   04.jpg   05.jpg  

    06.jpg   07.jpg   08.jpg   09.jpg   10.jpg  

    11.jpg   12.jpg  
    www.gregorytdavis.com

    Did millions of people suddenly disappear? This may have an answer.

    "No one knows that day or hour, not even the angels in heaven, nor the Son, but only the Father." -Matthew 24:36

  2. #12
    RalphLambrecht's Avatar
    Join Date
    Sep 2003
    Location
    Central florida,USA
    Shooter
    Multi Format
    Posts
    6,804
    Images
    1
    Greg

    Thanks for the effort. It's a good comparison.

    I have a suggestion for when you do this next time. Pick a tone (maybe a highlight around Zone VII or VIII) and make sure to keep the exposure that tone consistent. That will give a more relevant comparison between the pictures. If no tone in the two pictures are the same is harder to quantify the change.

    I attached an example where the density of the white wall in the wood-frame building is constant in both pictures.
    Attached Thumbnails Attached Thumbnails KottenDif2.jpg   KottenCon2.jpg  
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  3. #13
    Greg Davis's Avatar
    Join Date
    Feb 2004
    Location
    Crestview Hills, KY
    Shooter
    8x10 Format
    Posts
    1,950
    There are tones that are constant. Particularly the skin between my eyebrows, which is what I was using as a basis. The Zone VIII tones blew out very quickly as the contrast went up, so I chose more of a midtone that stayed consistent from print to print and from one light source to another.
    www.gregorytdavis.com

    Did millions of people suddenly disappear? This may have an answer.

    "No one knows that day or hour, not even the angels in heaven, nor the Son, but only the Father." -Matthew 24:36

  4. #14

    Join Date
    Feb 2005
    Location
    Richmond, VA
    Shooter
    Multi Format
    Posts
    1,066
    Greg - which diffusion head did you use? An Arristo V54 lamp performs very differently from an older Aristo lamp.

  5. #15
    Greg Davis's Avatar
    Join Date
    Feb 2004
    Location
    Crestview Hills, KY
    Shooter
    8x10 Format
    Posts
    1,950
    It is an Omega D5 with the dichroic color head.
    www.gregorytdavis.com

    Did millions of people suddenly disappear? This may have an answer.

    "No one knows that day or hour, not even the angels in heaven, nor the Son, but only the Father." -Matthew 24:36

  6. #16
    RalphLambrecht's Avatar
    Join Date
    Sep 2003
    Location
    Central florida,USA
    Shooter
    Multi Format
    Posts
    6,804
    Images
    1
    Quote Originally Posted by Greg Davis View Post
    There are tones that are constant. Particularly the skin between my eyebrows, which is what I was using as a basis. The Zone VIII tones blew out very quickly as the contrast went up, so I chose more of a midtone that stayed consistent from print to print and from one light source to another.
    I see, I see!
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  7. #17
    Greg Davis's Avatar
    Join Date
    Feb 2004
    Location
    Crestview Hills, KY
    Shooter
    8x10 Format
    Posts
    1,950
    I have to admit, it was a darker tone than I had expected. I was always taught that the highlights would remain similar as the contrast changed and the lower tones would get even lower (when going up in contrast). I wanted to test Ilford's claim that the printing time was constant when changing filters, so I made the best grade 2 I could, then printed a grade higher and lower, expecting the highlights to stay and everything else move. I found that the lighter midtones matched, but highlights (Zone VIII) blew out, while shadows got very dense when going up in contrast, and everything got muddy when lowering contrast.
    www.gregorytdavis.com

    Did millions of people suddenly disappear? This may have an answer.

    "No one knows that day or hour, not even the angels in heaven, nor the Son, but only the Father." -Matthew 24:36

  8. #18
    RalphLambrecht's Avatar
    Join Date
    Sep 2003
    Location
    Central florida,USA
    Shooter
    Multi Format
    Posts
    6,804
    Images
    1
    Quote Originally Posted by Greg Davis View Post
    ... I was always taught that the highlights would remain similar as the contrast changed and the lower tones would get even lower (when going up in contrast). I wanted to test Ilford's claim that the printing time was constant when changing filters, so I made the best grade 2 I could, then printed a grade higher and lower, expecting the highlights to stay and everything else move. I found that the lighter midtones matched, but highlights (Zone VIII) blew out, while shadows got very dense when going up in contrast, and everything got muddy when lowering contrast.
    Greg

    Paper curves are non-linear. Hence, exposure during contrast changes can only be constant for a fixed paper density. The ISO standard for photographic papers picks a fixed density of 0.6>base+fog to do that. This is a medium gray between Zone V and VI, and darker than I would hope for. For this density, the Ilford and Kodak 'claims' are valid (see 1st attachment). If you like to calibrate your papers for a different density, you need to make your own tables (see 2nd attachment).
    Attached Thumbnails Attached Thumbnails PaperSpeedPoint.jpg   ExpTable.jpg  
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  9. #19
    Greg Davis's Avatar
    Join Date
    Feb 2004
    Location
    Crestview Hills, KY
    Shooter
    8x10 Format
    Posts
    1,950
    Thanks, Ralph. I have no plans on changing how I print as it has always worked for me, but my findings contradict, or at least put into doubt, the common saying, "print for the highlights and change filter for the shadows." Doing so, as demonstrated by my prints, would increase the highlight density, as well, if I use the same printing time as per the manufacturer's instructions. The main point, however, is to visually demonstrate the effects of the contrast filters with two different light sources so the photographer (or my students) can choose the most appropriate tool for their work. I have plans for other visual tools, such as a set of negatives developed with no agitation, standard agitation, and constant agitation to show the effects on image density and contrast. I also plan to add to the original batch a set of prints using the color head filtration vs. Ilford's filters vs. Kodak's filters.
    www.gregorytdavis.com

    Did millions of people suddenly disappear? This may have an answer.

    "No one knows that day or hour, not even the angels in heaven, nor the Son, but only the Father." -Matthew 24:36

  10. #20
    RalphLambrecht's Avatar
    Join Date
    Sep 2003
    Location
    Central florida,USA
    Shooter
    Multi Format
    Posts
    6,804
    Images
    1
    Quote Originally Posted by Greg Davis View Post
    ... but my findings contradict, or at least put into doubt, the common saying, "print for the highlights and change filter for the shadows." Doing so, as demonstrated by my prints, would increase the highlight density, as well, if I use the same printing time as per the manufacturer's instructions. ...
    The method is called 'exposing for the highlights and adjusting the shadows with contrast', and it is solid advise. Your findings and prints don't contradict it, because you obviously did not change the exposure to keep the highlights at a consistent density. The manufacturer's claim that exposure does not change with filter changes is not true for highlights. It's true for midtones as demonstrated by your prints.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

Page 2 of 3 FirstFirst 123 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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