I had an epiphany whiles shopping with my daughter - I was thinking about why I am always over exposing. My main concerns were with aperture and shutter speed and I did not rate ISO as a terribly important factor, maybe that's being harsh. I did know that it was relevant I just didn't realise how much. I think most of these shots that I have taken were on a 400ISO setting, when it should of been on 100, 200 at max (Outside, harsh light shots).

I joined up to a Photography forum, where over the last few days I have been spending my time, getting familiar with the navigation of the site and posting comments and images. Today I even posted to a competition - looking at the other entrants, I'm not holding my breath. Anyway this forum also has learning material and activities to do, so I have been reading up. The biggest lesson this week is the ISO and what it means.

Each digital camera has a light sensor and this acts in a similar way to the age old film. I often wondered why film had this ISO terminology - I just new that it stood for International standards and that it ranged from 100 to 400. In high, harsh light use 100ISO film, in cloudy and dark areas use 400ISO film.

What I have linked today is that that film had grades of sensitivity. 100ISO film was less sensitive to light than 400ISO film. This is also true with the digital sensor in a DSLR camera. The 100ISO setting will set the cameras sensor as less sensitive to light, therefore use in well lit, sunny day environment (outdoors). The 400ISO setting will set the cameras sensor at a higher sensitivity, therefore best used when light is at a minimum, e.g cloudy overcast days or inside a darkish house.

In fact as I reflect and write, the ISO setting should be the first thing you consider when taking a shoot or picture. Evaluate the light in the environment - not only the light source itself and direction but also the saturation of light.

So if I was to write a 10 point checklist of what to do when taking an image - evaluating the light and light source and selecting the appropriate ISO setting would be in the top three in the list, maybe even number 1.

For me if I want to take a quick shot of my daughter especially in a setting where I will not get time to think or prep the best setting for me to use would be a scene mode - because everything is set for me.

I would like to thank the members of Ausphotography for the information and learning modules and for the feedback and advise.