Pinhole photography light metering - Sekonic Blog

Discussion in 'Pinhole Photography' started by PhotoBob, May 27, 2013.

  1. PhotoBob

    PhotoBob Subscriber

    Messages:
    540
    Joined:
    Feb 16, 2006
    Location:
    Victoria, BC
    Shooter:
    Multi Format
    -

    Modest article on measuring light with a metre.
    Sekonic blog
     
    Last edited by a moderator: May 27, 2013
  2. pdeeh

    pdeeh Member

    Messages:
    3,527
    Joined:
    Jun 8, 2012
    Location:
    UK
    Shooter:
    Multi Format
    I think he can't spell "meter :smile:
     
  3. PhotoBob

    PhotoBob Subscriber

    Messages:
    540
    Joined:
    Feb 16, 2006
    Location:
    Victoria, BC
    Shooter:
    Multi Format
    No, he knows how to spell.
     
  4. munz6869

    munz6869 Subscriber

    Messages:
    1,194
    Joined:
    May 17, 2004
    Location:
    ɐıןɐɹʇsnɐ 'ɐıɹoʇɔıʌ
    Shooter:
    4x5 Format
    Yes, the wrong meter is annoying, especially for us metric folk... Otherwise, the article is interesting!

    Marc!
     
  5. TheToadMen

    TheToadMen Subscriber

    Messages:
    3,000
    Joined:
    Sep 18, 2012
    Location:
    Netherlands, EU
    Shooter:
    Pinhole
    Hi pdeeh,
    you're wrong: Bob's Sekonic is a French model, see: http://www.sekonic.com/downloads/C-500_Operating_Manual_French.pdf
    Also called: "un instrument demesure de la lumière".
    And a beautiful language it is, French! I'm still sorry I didn't learn it properly in High School.
    If you don't know what French sounds like, watch the movie "Intouchables" (French version with English subtitles). You'll laugh your "chaussettes" off.
    intouchable.jpg

    Hi Bob,
    I like your conclusion in the article: "Even with metering, pinhole photography is not an exact process, which makes it somewhat artistically unique, challenging but enjoyable. I believe there is something significant to be said for the immediate unknown … for patience … for critical thinking … for anticipation when waiting for paper or film to be processed."
    I totally agree. Using digital aids isn't forbidden (not even for artists) but in the end, it still is only an end to a mean (or whatever the phrase is...). Pinhole is a way of live, not an technique.

    My only problem with (most of) the light meters is being unable to set for ISO 1 and f/512, thus having to make do with tables, calculating, etc.
    I now use a simple app (see also: http://www.apug.org/forums/groups/p...t-meter-app-suitable-pinhole-photography.html) or even better: guestimation. If you use your pinhole camera often enough, you'll get the hang of it.
    It worked well for me at my shoot on WPPD 2013.

    But it is always nice to be able to measure with a proper light meter, especially when I use a camera like my Leica III (1936) or my Bronica SQ-B.
    Every photographer should have a handheld light meter, just for the sake of it....
    I myself use Gossen light meters. The Gossen Digisix is very small and can even be attached onto your camera.
    digisix-on-camera.jpeg
     
  6. pdeeh

    pdeeh Member

    Messages:
    3,527
    Joined:
    Jun 8, 2012
    Location:
    UK
    Shooter:
    Multi Format
    It's amazing what people will overlook.

    Here is his first paragraph, quoted directly :

    That is not how you spell "meter" when referring to a measuring device.

    A "metre" as the rest of us Europeans know, is a measure of length

    In his next paragraph he reverts to conventional spelling of "meter", however, but then goes on to use "meter" and "metre" indifferently throughout the rest of the article.
     
  7. PhotoBob

    PhotoBob Subscriber

    Messages:
    540
    Joined:
    Feb 16, 2006
    Location:
    Victoria, BC
    Shooter:
    Multi Format
    Meter

    Why is there such a fuss over one single word.

    Unfortunately, you are missing the point about the article.
    It was about one man's experience measuring light for making pinhole exposures.

    Sorry for spelling one word wrong ... does it affect the content of the article?

    Maybe Bob should just keep all his experiences, skills and knowledge to himself ... silence is golden I guess.
     
    Last edited by a moderator: May 31, 2013
  8. Loris Medici

    Loris Medici Member

    Messages:
    653
    Joined:
    Sep 13, 2005
    Location:
    Istanbul, Tu
    Shooter:
    Multi Format
    Hi all,

    I do it (maybe) in a little more practical way:

    - My pinhole camera (Zero 45) has many different focal lengths and pinhole diameter combinations, and
    - My meter measures up to F32. (Sekonic L-208)
    Therefore,
    - I meter for F32 then multiply this with a factor determined before (more on this below), and then
    - If the resulting exposure time exceeds 1 sec. I further adjust it for reciprocity failure using this (Ilford) formula: New time = Calculated time ^ 1.48 or in Excel notation: New time = POWER(Calculated time, 1.48)

    It's hard to remember and calculate each factor, therefore I prepared a simple Excel chart, printed it, and had it laminated with PVC. I keep this chart (and a scientific calculator) with the camera all the time...

    See the chart (and the two formulas that I've used) below:

    Formula #1:
    Pinhole-Calculation-Table-Formula_1.jpg

    Formula #2:
    Pinhole-Calculation-Table-Formula_2.jpg

    Hope this helps if you ever need to make your own practical exposure calculation charts,
    Loris.

    P.S. Beware, the reciprocity failure correction formula applies only to Ilford B&W films!
     
    Last edited by a moderator: May 31, 2013
  9. PhotoBob

    PhotoBob Subscriber

    Messages:
    540
    Joined:
    Feb 16, 2006
    Location:
    Victoria, BC
    Shooter:
    Multi Format
    I can't see how one little word could be so annoying ... I just don't get it.
    Is there no substance to the article.
    Is this forum part of the issue I wonder.
     
  10. SMBooth

    SMBooth Member

    Messages:
    1,143
    Joined:
    Jun 29, 2008
    Location:
    Melbourne, N
    Shooter:
    Multi Format
    I think it come down to the fact the basically people are rude. It doesn't matter what work somebody put into some thing people will find the smallest issue and harp on it.
     
  11. Molli

    Molli Subscriber

    Messages:
    636
    Joined:
    Dec 28, 2009
    Location:
    Victoria, Australia
    Shooter:
    Multi Format
    Hi Bob,

    I'm sorry to see that your link disappeared from your original post, but tracked the article down via your blog site anyway. I found your article really interesting, concise and easily understood - not just the how, but the why of using a light meter for pinhole work. Thanks for taking the time to write up the article and also for sharing it with those of us who enjoy learning new things and hearing about how others work.
     
  12. PhotoBob

    PhotoBob Subscriber

    Messages:
    540
    Joined:
    Feb 16, 2006
    Location:
    Victoria, BC
    Shooter:
    Multi Format
    Thank You SM Booth ... that is a very sad commentary on human nature :sad:
    On the other hand, I have mitigated the word spelling, so it should be okay now.
     
  13. DWThomas

    DWThomas Subscriber

    Messages:
    2,918
    Joined:
    Jun 13, 2006
    Location:
    SE Pennsylvania
    Shooter:
    Multi Format
    Ignoring the pedantry --- in attempting to view this article, the intro (and apparently link) to it on your site is obscured by a redbubble slide show that I can't seem to get around?

    (Running Firefox 21.0 on Win7 64bit for the 2 cents that may be worth.)

    Although pinhole is not my primary interest, I have participated in WPPD every year since 2005 and keep using it as an excuse to indulge in some crazy craftsmanship on cameras! :laugh:

    Similar to what Loris describes, I normally make myself a pocket sized chart that goes from an exposure time for f/22 to what's needed for the specific film and camera; using reciprocity compensation if needed. The program Pinhole Designer can actually produce an Excel spreadsheet table** using readings at f/22 and has compensation for a few films built in. I usually reformat and truncate the chart, as a compensated exposure of 1795 hours seems unlikely, since I don't normally add a folding cot to my gear!

    ** The latest updates of Office 2007 grumble about possible security risks when opening said table, no doubt because the program dates back to the start of the millennium.