Night Exposures - In A Jiffy

Discussion in 'General Discussion' started by Chris Dodkin, Jan 23, 2014.

  1. Chris Dodkin

    Chris Dodkin West Coast Correspondent

    After Hamish posted his night shots with the Fuji Klasse the other day, I remembered a little exposure aid that helped me in such situations.

    I love shooting after sunset – the limited dynamic range of twilight, the rich colors in the sky after the sun has long gone, the twinkling lights of a distant city, the trails of car lights along a freeway.

    The problem comes when you try and estimate the exposure in these lighting conditions. If you have an old school film camera, your meter may not work at such low light levels, or you may not even have a light meter on the camera.

    Your hand-held light meter might get you a reading – but it’s most likely going to have to be a spot meter (not cheap), and even then, you have to figure out what to point it at, and what that reading would mean for a ‘correct’ exposure.

    Your modern digital camera might be a good bet – the metering is more advanced, you often have a live view histogram to view exposure information, and you can at least review your shots as you go, and make adjustments accordingly. But even modern meters can be easily fooled by bright point sources, or highly contrasty scenes – and photography after dark is full of both!

    So here’s where you roll back the clock to 1968, and pick up The Jiffy Calculator – For Night-Light Exposures.


    This is a cardboard ‘slide rule’ – given away on the cover of Popular Photography in 1968, and originally designed by one S. P. Martin.

    Mr Martin’s idea was simple – list out a range of possible lighting conditions that the night-time photographer might face – number them from lightest to darkest.


    You go down the list and find the nearest fit to your lighting conditions, then find that scene number on the front of the calculator, and slide the internal ASA film speed card to match your film ASA against the selected scene number.


    So in this case, maybe I’m shooting a night scene, dimly lit – and I’m using 50 ASA film.

    I’ve matched 50 ASA against scene #19.

    Now I look across to the F-Stop column, and find the aperture I’m using.

    Let’s say f/22 in this case – so looking at f/22 I see an exposure time of 4 minutes next to it.

    I transfer these settings across to my camera, and take my shot.

    Now if this is digital – I’m probably good to go.

    But if it’s film, then I need to take film’s reciprocity failure into account – unfortunately film’s response in low light is anything but linear, so a good practice is to take additional shots at 1 stop either side of the recommended settings.

    This bracketing should get me a clean, well exposed shot.

    Now this may all seem terribly old fashioned, but time hash’t changed the basic physics behind these exposures, so information from 1968 is just as relevant in 2014.

    And it gets you in the ballpark on the first shot – no more guessing and cursing.

    You can find the original Jiffy Calculator on EBAY, or modern printed versions in online stores, or you can go DIY and print and make your own.

    Just download and print this PDF, and you could have your own Jiffy Calculator, in a jiffy!

    Worth slotting into your camera bag – it’ll save you a lot of time and frustration.
  2. Beth Anthony

    Beth Anthony Well-Known Member

    thanks chris. just saved this to my phone so i don't have to print it.
    Chris Dodkin likes this.
  3. Dan Cattermole

    Dan Cattermole Dan Down - The Steampunk Womble

    Well thank you very much for that Chris. Very useful stuff that....
  4. Lesley Jones

    Lesley Jones Otherwise know as Zooey

    I was about to do the same, but I'm thinking it does need to be printed and used as it was originally...:confused:
  5. Kev Pugh

    Kev Pugh Well-Known Member

  6. Chris Dodkin

    Chris Dodkin West Coast Correspondent

    I was looking for an APP version of this but have yet to find one - would be a winner!

    You're most welcome Dan :)

    Very true - hard to slide the sliding bit on a PDF!

    Thanks Kev
  7. Beth Anthony

    Beth Anthony Well-Known Member

    i looked too and couldn't find one so i started one last night using mit's app inventor 2.. we'll see how/if it turns out.
  8. Chris Dodkin

    Chris Dodkin West Coast Correspondent

  9. Brian Moore

    Brian Moore Moderator

    Excellent, Chris. Thanks.
  10. Pete Askew

    Pete Askew Admin

    Thanks Chris. Crystal clear as always! :)
  11. Hamish Gill

    Hamish Gill Well-Known Member

    Cracking post, some great descriptions of the light level on that thing!
  12. Chris Dodkin

    Chris Dodkin West Coast Correspondent

    you're welcome

    Clear as mud eh Pete ;)

    Thanks Hamish - they are a little old fashioned aren't they! :D
  13. Pete Askew

    Pete Askew Admin

    But they don't need re-charging as often as an iPhone! ;)
    Chris Dodkin likes this.
  14. Ahmad Bhai

    Ahmad Bhai Well-Known Member

    Chris I really like this. Even though im a tech nut (thus checking out latest cameras & gadgets ... go gadget go o_O)
    anything printed, handwritten (analogue) just greases my gears.
  15. Chris Dodkin

    Chris Dodkin West Coast Correspondent

    Me too - and for some reason I think it's cool that advice from the 60's still applies! :D
  16. Dave Young

    Dave Young Active Member

    Perfect! Thanks Chris, could have done with this just recently on my travels to Budapest.
    Chris Dodkin likes this.

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