Pentax Spotmeter V

Discussion in 'Exposure Discussion' started by bmac, May 16, 2003.

  1. bmac

    bmac Member

    Messages:
    2,156
    Joined:
    Sep 30, 2002
    Location:
    San Jose, CA
    Hey there,

    I just got a Pentax Spot Meter V. This is the first Pentax meter I have owned. Just checking it out to make sure it is working fine. I am trying to figure out if iso speed should affect ev reading on the manual dial. Say I get a reading of EV7 with ISO 100 film, then take the same reading with the meter set to ISO 400 speed should the meter still be reading EV7? This isn't how it works on my Minolta Autometer IV.

    Brian
     
  2. Loose Gravel

    Loose Gravel Member

    Messages:
    921
    Joined:
    Feb 28, 2003
    Location:
    Santa Barbar
    The number in the viewer is not EVs, it is just a number that is used on the dial of the meter to calculate exposure. At 100 ASA, it is EV, but just consider that a coincidence. The dial and the readout are not interactive.
     
  3. bmac

    bmac Member

    Messages:
    2,156
    Joined:
    Sep 30, 2002
    Location:
    San Jose, CA
    That is what I Figured, thanks for the quick response. Can I assume that the difference between 4 and 5, etc is one stop?
     
  4. Donald Miller

    Donald Miller Member

    Messages:
    6,242
    Joined:
    Dec 21, 2002
    Shooter:
    Large Format
    Yes, the difference you described would be one stop of exposure.
     
  5. bmac

    bmac Member

    Messages:
    2,156
    Joined:
    Sep 30, 2002
    Location:
    San Jose, CA
    Thanks! Who needs a manual when you have you guys!

    Brian
     
  6. Donald Miller

    Donald Miller Member

    Messages:
    6,242
    Joined:
    Dec 21, 2002
    Shooter:
    Large Format
    Brian, I don't know about your Pentax V...but on my Pentax digital there are also marks that determine 1/3 stop differientations. On my meter they occur as dots in the read out following the number.
     
  7. fhovie

    fhovie Subscriber

    Messages:
    1,247
    Joined:
    Mar 20, 2003
    Location:
    Port Hueneme
    Shooter:
    Large Format
    I bought a no-name analog spot meter a few months ago and did a test with it to calibrate it with the film-developer-paper-paper developer combo I am using and it all seemed to match up fine - all ten zones. I then found a digital pentax with zone vi mods for $150 and couln't pass it up. They agree on the highlights almost always but from ev9 and down, they can be as much as 2 ev different. The Pentax showing lower values. I tried to determine if color was the issue and maybe the Pentax views greens differently. I am thinking that the clone goes in the kit for color and the pentax will be my main-stay.

    How different is a zone vi mod unit from the regular ones?

    Has anyone had trouble with a Pentax spot meter?

    Frank
     
  8. juan

    juan Subscriber

    Messages:
    1,699
    Joined:
    May 7, 2003
    Location:
    St. Simons I
    Shooter:
    Multi Format
    According to his newsletter, Fred Picker had trouble metering green, particularly, with his meters, including the Pentax. That's what led him to develop his own. The Zone VI modifications, AFAIK, included filtration and a new sensor that reads light more like film does.
    I have an unmodified Pentax, and I don't trust the low readings. I usually meter and place at Zone VI or above and let the low values fall where they will. I still meter the low values, but it's more intuitive there.
    That was with Tri-X, HC-110b and the old Zone VI graded paper and the old Oriental Seagull (it's been a while since I've done much photography.)
    I'm testing the ABC, Azo, Amidol process (or will be when all the stuff gets here) so I may change my mind about the process.
    I'd recommend making proper proofs, keeping records of your meter readings and paying attention. I think our analog stuff will always require intuition.
    j
     
  9. Donald Miller

    Donald Miller Member

    Messages:
    6,242
    Joined:
    Dec 21, 2002
    Shooter:
    Large Format
    The Zone VI modifications that Fred Picker, along with Dr. Horowitz, developed amounted to UV and IR filters, sharp cutting filters that allow the meter to read colors more accurately (as they are read by panchromatic film emulsions), and internal baffling to be resistant to adjacent bright light sources. I have used both the Pentax digital (unmodified) and the same meter later modified by Zone VI. My experience indicates that the modifications are beneficial in metering for black and white photography. I have no experience using the meter for color, since I do not do color photography any longer.

    The matter of accurately metering green foliage is one of the IR emissions. If you will refer to an IR film photograph involving foliage, you will note that the foliage is very light in tonality. The reason is that foliage emits a large amount of IR. The unmodified meter will be sensitive to this IR and give a higher reading then what panchromatic film is capable of exposing (since it is not sensitive to IR). Therefore in using an unmodified meter when exposing foliage, the negative when developed will have lower densities. The print, from this negative, consequently does not well differentiate the tonalities in the foliage.
     
  10. Aggie

    Aggie Member

    Messages:
    4,925
    Joined:
    Jan 1, 2003
    Location:
    So. Utah
    Shooter:
    Multi Format
    ..
     
  11. JHannon

    JHannon Member

    Messages:
    969
    Joined:
    Sep 7, 2002
    Location:
    Boston, MA
    Shooter:
    Multi Format
    Richard Ritter worked for zone VI and still does repairs and has parts for the Pentax and Soligor spot meters. He should be able to answer your questions.

    http://www.lg4mat.net/

    Regards,
    John
     
  12. Loose Gravel

    Loose Gravel Member

    Messages:
    921
    Joined:
    Feb 28, 2003
    Location:
    Santa Barbar
    Industrial Light and Metric calibrates meters. I think they are in Hollywood or Burbank. Meters don't go out of cal unless you drop them or otherwise abuse them and even then sometimes they're ok.

    Some new meters, Pocket Spot for one, have no means to calibrate, in the conventional sense. They are digital all the way to the very front end of the electronics and there is nothing to adjust.