Densitometer Dilemma

Discussion in 'Darkroom Equipment' started by Doc W, Oct 9, 2013.

  1. Doc W

    Doc W Subscriber

    Messages:
    514
    Joined:
    Nov 7, 2009
    Location:
    Ottawa, Cana
    Shooter:
    Large Format
    My old MacBeth densitometer was getting a little wonky so I just bought an Xrite 820 from ebay and I think I made a mistake. I retired from hi tech in the hope that I would never again have to read a turgid manual. Holy SMOKES! All I want to do is find the density of test strips on black and white negatives. I think that this machine probably solves the four colour map theorem while making coffee. It is wAAAAY over my head.

    Does anyone else use one of these for the very limited purpose of black and white negs? I could use some advice.
     
  2. Chan Tran

    Chan Tran Member

    Messages:
    2,374
    Joined:
    May 10, 2006
    Location:
    Aurora, IL
    Shooter:
    35mm
    Should be easy to use. Just read the visibility channel.
     
  3. Prof_Pixel

    Prof_Pixel Member

    Messages:
    1,487
    Joined:
    Feb 17, 2012
    Location:
    Penfield, NY
    Shooter:
    35mm
    You can get the manual at http://bit.ly/1e9MIHd if you don't already have one. And, yes, it's a bit complicated
     
  4. AgX

    AgX Member

    Messages:
    11,951
    Joined:
    Apr 5, 2007
    Location:
    Germany
    Shooter:
    Multi Format
    X-Rite:
    Well...
     
  5. Doc W

    Doc W Subscriber

    Messages:
    514
    Joined:
    Nov 7, 2009
    Location:
    Ottawa, Cana
    Shooter:
    Large Format
    AgX, you got it! That is a bit like saying "Briefly look through the local library..."

    If anyone has one of these things, I could use some help.

    Chan: what IS the "visibility channel" and how do I find it?
     
  6. Prof_Pixel

    Prof_Pixel Member

    Messages:
    1,487
    Joined:
    Feb 17, 2012
    Location:
    Penfield, NY
    Shooter:
    35mm
    Lots of densitometers have V,R, G and B channels. V is for 'visible'. I see mention in your manual to a 'Black' channel.
     
  7. Bill Burk

    Bill Burk Subscriber

    Messages:
    4,984
    Joined:
    Feb 9, 2010
    Shooter:
    4x5 Format
    Looks like you need to push button 5, then push button 2 until it says tranM.

    Then push the read head button and look at the result on the display...

    If that works, you've got it. If not, then the instructions are too complicated for me too.
     
  8. Doc W

    Doc W Subscriber

    Messages:
    514
    Joined:
    Nov 7, 2009
    Location:
    Ottawa, Cana
    Shooter:
    Large Format
    I seem to be getting somewhere - thanks for the tips. Now how do I calibrate the damn thing? I tried a step wedge with known values and it reads very low.
     
  9. Europan

    Europan Member

    Messages:
    146
    Joined:
    May 21, 2009
    Location:
    Basel, Switzerland
    Shooter:
    Multi Format
    This is what I use. Simple and reliable

    Komparations-Densograph_ICA,_1920er_Jahre_001.jpg
     
  10. ic-racer

    ic-racer Member

    Messages:
    7,473
    Joined:
    Feb 25, 2007
    Location:
    Midwest USA
    Shooter:
    Multi Format
    Page 60 and 61. Press the appropriate buttons on the machine and enter your value from your step wedge around 2.0 to 3.0 or so.

    But, you say your step wedge 'standard' only has a single density number indicated for each step?? Then enter that same number for all the color channels on the machine.
     
  11. Doc W

    Doc W Subscriber

    Messages:
    514
    Joined:
    Nov 7, 2009
    Location:
    Ottawa, Cana
    Shooter:
    Large Format
    I don't have the step wedge shown in the manual. The step wedge I have is the one I used with my old MacBeth and as far as I know, it was made by the previous owner. It is more of a test strip really, with 9 steps from 0.04 to 1.77. Not really enough I don't think. I have a Stouffer step wedge which I read with my MacBeth. I still have those values (21 steps, 0.05 to 3.05).

    I am still baffled by the calibration procedure. I only want to use this device for b&w.

    Does anyone in APUG own one of these? I think I need to be walked through this procedure. It sure isn't intuitive.
     
    Last edited by a moderator: Oct 10, 2013
  12. ic-racer

    ic-racer Member

    Messages:
    7,473
    Joined:
    Feb 25, 2007
    Location:
    Midwest USA
    Shooter:
    Multi Format
    RE- read page 61 please. Press the buttons indicated on that page. Then enter 1.77 for all color values. Then make a reading with nothing under the probe then make a reading with your 1.77 under the probe. According to the manual that is all there is to calibrate it.


    Then read the strip as in page 19 to see that it reads 1.77 and you know it is calibrated. Use status A and BLACK channel for all your readings.
     
    Last edited by a moderator: Oct 10, 2013
  13. Doc W

    Doc W Subscriber

    Messages:
    514
    Joined:
    Nov 7, 2009
    Location:
    Ottawa, Cana
    Shooter:
    Large Format
    Success!

    ic, you got me very close, but it still didn't work. The manual neglects to tell the poor user that you must hit the "continue" option between two crucial steps or it just doesn't work. I admit to being somewhat dyslexic when it comes to manuals (seriously! it's no joke) but this manual is really one of the worst.

    However, all's well that ends well. Thanks to all for your efforts. A special thanks to ic for encouraging me to focus on being meticulous in following the procedure. It is too bad that all of you can't be here. We could crack open a bottle of ... something... and measure some negatives!!! :D
     
  14. ic-racer

    ic-racer Member

    Messages:
    7,473
    Joined:
    Feb 25, 2007
    Location:
    Midwest USA
    Shooter:
    Multi Format
    Good to see it working. You might want to write down how you did it. I'm good with this sort of thing, but if I don't write it down, a year later I go through all the same exploratory steps to figure it out again (and repeat all the mistakes!).