The Old Calibrated Eyeball

Back in the olden days, when we geezers walked five miles to school, up hill each way in the snow – you know, before digital photography – each roll of film came with an instruction sheet.  That rarely read sheet had tons of useful information, including exposure instructions for daylight photography. Back then, most cameras did not have built in light meters or automatic exposure systems.  For those who had been at the game long enough, outdoor exposures were made mostly by “calibrated eyeball”, and for most of us the process of calibrating our eyeballs started with reading the film instruction sheet and memorizing what is commonly known as the Sunny 16 method of exposure. Basically intended for amateur photographers shooting vacation photographs, Sunny 16 was a table of suggested exposures for a range of daylight conditions:  if you were shooting Kodak Plus X film with an ASA (ISO) of 125, your settings in bright sun would be 1/125th of a second at f/16; slight overcast 1/125 at f/11; overcast 1/125 at f/8; you get the drift. If f/11 was your favorite f/stop, then you would adjust your shutter speed up to 1/250th of a second for exposures in the bright sun.  If you got good at this, you could easily begin to mentally do the compensations to account for the use of Wratten filters in black and white photography.  Which brings us to today’s photograph:

_DSC1779 Gallery

I took a short drive into Old Town Alexandria to photograph the old Jones Point light house.  I had my multi-megapixel, auto-everything camera with me, but it was set, as usual, to manual, all Auto systems off.  As I walked from the parking lot to the light house I found myself almost subconsciously computing the Sunny 16 exposure:  it was a bright day and I wanted to use ISO 64, giving me an initial exposure of 1/60th second at f/16.  But, I wanted to shoot at f/11 (it is my favorite f/stop, bar none), so my starting shutter speed had to be adjusted to 1/125th instead of 1/60th, meaning I could comfortably shoot handheld if I chose to do so.  Because the light house is white clapboard, and I didn’t want to blow out my highlights, I built in 1/3 stop of underexposure by increasing my shutter speed to 1/160th.  That was it – my exposure settings for the entire session were ISO 64, 1/160, f/11.  I will confess to “chimping” the image histograms on the preview screen from time to time, which is a feature of digital I truly like.  But, all my exposures were pretty much spot on without resorting to a light meter, and the proof is today’s photograph – a full tonal range image with details in both the highlights and the shadows.

Two lessons came out of this exercise for me: that no matter how much our equipment changes or how sophisticated it becomes, for the most part, the actual act of making a photograph really hasn’t changed; and, that as long as we have that big fireball in the sky (without intervening clouds) a perfect daylight exposure will always be the reciprocal of your ISO (1/ISO) at f/16. Or, thereabouts.

Thanks for stopping by.