It may be a bit odd to consider how the AF (auto-focus) illuminator can be used as a creative tool to change the emphasis in your images especially with portraits, candid’s and street photography.
In Fine Art Photography, there is often a lot of discussion as to wether the subject is, or was, camera aware! Meaning; did they know they were, or might be photographed. Non of which maters outside the elite fine art schools however, so I am not going into a philosophical debate here as there is no right or wrong answer, but look at ways on how you can make the subject respond to your wishes.
AF Illuminator off: The idea with candid photography is they are ‘not’ aware of your presence OR intentions, so the AF illuminator should be off! The Canon G9 still focuses fine unless in low contrast situations like dingy, dark conditions or foggy, misty mornings as the AF illuminates and adds contrast to a scene.
AF Illuminator On: I discovered quite by accident that the AF illuminator light works constantly unless you turn it off. It’s not the same as my Nikon which automatically switches on, in low light conditions.
So there I am photographing people from the bus as it goes by, and realising they all keep looking up, puzzled, with some occasional angry glares. I only realised when taking a picture of myself in a mirror just how intense that green light is, and it was on! Oops… (well that will make my friend a bit happier over on ‘Adventures of an Idiot-occasional notes of a photo freak’ who writes about his photography mistakes, as it shows we all make them and it not just him, honest Mike!)
From that, now happy accident (a fine art term) I found the interaction is quite interesting as more random strangers were looking directly at me in a very natural way. So it has potential for some interesting shots. It also gets the attention form small children and the occasional pet when they are not expecting it and gets them to look at the camera, but don’t over do it all in one session, even pets and children will get bored of being dazzled with intense green light unless they are weird or are trying really hard to please you photographic endeavour.
If you are wanting to use the optical viewfinder as a way of composing and shooting, it is hard to give advice as to wether the AF Illuminator should be on or off, that said if you are shooting dark subjects the AF Illuminator will show a little green dot on the subject (like a laser sight from the movies, but green and un-focused; OK, so its not like that at all!) but it is easier to see than the black un-illuminated cross hairs in the viewfinder against dark subjects. so it might be best to have it switched on.
AF Illuminator On: As I mentioned above, if the G9 is struggling to focus like in a night club, a foggy day or even in macro shooting (you may be blocking available light) it’s best to leave switched on. The AF illuminator won’t help focus over very long distances such as landscapes and you may need to switch to Manual Focus (MF) That said if there is light the lens should focus at infinity, or if you can’t see well enough yourself set the lens manually to infinity and all should be good.
The AF Illuminator can also be used as an emergency torch as it always switches on when AUTO is set on the mode dial and the shutter button is pressed half way down, ideal for a quick search in your camera bag, or looking for the key hole. All you have to remember in the number 4 as its four clicks from the gap in the shooting modes on the mode dial going anti-clock wise, play with it and you will see what I mean.
The down side to all this is there is no easy method to change the AF Illuminator without going into the menu and scrolling through.