A wire sculpture figurine, with Bondi Beach in the background.

All Wired Up

"Chaos and Order" by Barbara Licha, Sculpture By The Sea, Bondi 2009

Bondi Beach, Sydney, New South Wales
Canon EOS 50D, 70-200mm f/4L @70mm, 1/2500 sec, f/4, ISO100

This photo was taken last year in October, at the Scultpure By The Sea exhibition at Bondi, Sydney.
This particular piece is titled "Chaos and Order", and is by Barbara Licha.

I was in Sydney for a few weeks for business, and on the weekend Igot together with a fellow photographer from OCAU, and spent an afternoon wandering around Bondi, and various other locations around Sydney.

This is the third article in a series on "understanding your camera" that I am writing as I teach camera basics and camera operation to my children.



Historically, ISO refers to the numerical scale used to measure the sensitivity of photographic film to light. Sensitive film (with a higher ISO rating) required less light to produce an image than less-sensitive film (with a lower ISO rating).

Several other scales were used in times past for measuring film sensitivity, but these were combined into a single standard, ISO 5800:1987, from the International Organization for Standardization (ISO).

The ISO system is now also used to measure the sensitivity of the sensors in digital cameras, but it is now set digitally, with the camera adjusting the signal gain of the sensor to provide similar results as would be achieved with film of the same ISO rating.



This table (taken from the first article in this series on understanding your camera) provides a summary of the effect of varying the ISO:

impact of varying the ISO

Doubling the sensitivity of a digital camera's sensor (or doubling the sensitivity of photographic film) equates to doubling the ISO number, and doubling the sensitivity will require half the amount of light to achieve the same exposure.

The ISO ratings on cameras typically starts at ISO 100 (some start at ISO 50), and then continually doubles, as follows:

            100, 200, 400, 800, 1600, 3200, 6400, etc

Here's another photo from July, taken on the Worldwide Photo Walk in Perth.
This is St Mary's Cathedral, in East Perth. Major expansion and repair work was completed in December 2009, and was one of the final places we visited on the photowalk.

St Mary's Cathedral

East Perth, Western Australia
Canon EOS 50D, 10-22mm @10mm, 1/125 sec, f/6.3, ISO100

I took this photo shortly after we left the Cathedral, as we were heading back to the car.
While the photo above is portrait orientation, I have also previously published a photo taken from almost the same spot in landscape orientation, and with a tighter crop.

A portrait of one of my nieces, shot at a family function a few months ago.

Allanah

Southern River, Western Australia
Canon EOS 50D, 24-70mm f/2.8L @70mm, 1/100 sec, f/4.5, ISO500