Friday, May 23, 2008

G9: Focus on Focusing

The G9 is an extremely versatile camera. Among its many options are (at least) five different choices for automatic focusing methods plus manual focus. I’ve always used the same method in the past but it is past time to learn the others so the next several posting will be about focusing the G9.

The G9 automatic focus methods are:

Flexizone – a single rectangular frame normally in the center of the display but which can be moved as desired. The frame can be large or small. The G9 focusing logic sets the focus distance so that the object in this frame is in focus.

AiAF – A 3x3 matrix of rectangular frames in the center of the display. These frames can be large or small. Only the small frame matrix can be moved off center. The G9 focusing logic somehow selects one or more of these frames and sets the focus distance accordingly. (“AiAF” apparently means “Artificial Intelligence Auto Focus” but I can’t find that definition in the manual.)

Face Detection – Magically, the G9 detects faces (or objects resembling faces) and sets the focus accordingly.

The autofocus mode is a menu setting (page 116 of the manual) as shown above but can also be set with a few button presses on the back of the G9 as shown here. First, with the G9 in shooting mode, press the AF frame button (numbered 19 on page 42 of the manual) shown circled here. The display will change as shown (but with the current AF frame selection). The AF frame selection is then toggled between Flexizone, AiAF and Face Detection by pressing the Menu button, examples are shown below.

For Flexizone and AiAF, the size of the frame can be changed by pressing the Display button, the smaller frames are shown below. Both Flexizone and the small AiAF frames can be moved with the Control Dial.

When in Face Detection mode, pressing the Display button indicates how many faces are detected.

When using the G9, I always recommend pressing the shutter button halfway to achieve focus. Once focus is achieved, the G9 gives two quick beeps and the focus frame turns green.

My normal practice is to use the small Flexizone frame in the center position to obtain focus on the subject of interest. I press the shutter button halfway to achieve focus, hold the button at the halfway position, recompose and shoot. To get a second or similar shot, I might switch to manual focus because the manual focus position is retained until the next autofocus.

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