Pentax IQZoom 70R IQZoom 70R Manual - Page 19

While continuing to press the shutter release button half-way, re-aim the camera or recompose the picture, then release the shutter. Notes: • You can cancel focus lock simply by taking your finger off the shutter release button. • When in the Consecutive Shooting mode (IQ), focus lock cannot be used. Hard-to-autofocus subjects Like many other autofocus cameras, this camera's autofocus system is highly precise, but is not almighty, so it may not focus as you wish on certain subjects. In such cases, use the focus-lock technique on a subject which is both near the actual one and equidistant from the lens. Subjects which are hard to autofocus include: 1. Black objects like hair, which don't reflect much light (and therefore don't reflect infrared autofocus beams). 2. Wire netting, latticework, iron exercise-bars, etc. 3. Flickering light sources such as neon signs, fluorescent lamps, TV images, sunlight coming through trees, etc., and subjects illuminated by these light sources. 4. Glossy and reflective surfaces like glass, mirrors, car bodies, etc. 5. Fast-moving objects, like trains in motion. 6. Water jets, water surface, smoke, frame, fireworks, etc., which have no distinct or consistent form, or a subject in mist. 15