Pentax IQZoom 70 IQZoom 70 Manual - Page 23

3 , 3. While pressing the shutter button half-way, reaim the camera or recompose the picture, and release the shutter. • During focus-lock operation, you cannot zoom. • You can cancel the focus lock by just releasing your finger off the shutter button. Hard-to-autofocus subjects The autofocus system of this camera is highly precise, but like many other autofocus cameras, the system is not almighty and may not properly focus on certain subjects. In such a case, use the focus-lock technique on a subject near and equidistant from the actual one. The subjects which are hard to autofocus are: 1. Black objects like hair, etc. which are hard to reflect light (infrared). 2. Wire netting, latticework, iron exercise-bar, etc. 3. Flickering light sources such as neon signs, fluorescent lamps, TV images, sunlight coming through the trees, etc., or any subject illuminated by these light sources. 4. Glass, mirrors, car bodies, etc. which are glossy and reflective. 5. Fast-moving objects like trains. 6. Water jets, surface of water, smoke, flame, fireworks, etc. which are formless. 21