Instruction manual

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4.1.6 Image Stabilization
Camcorders with an image stabilization feature helps to reduce (but not
completely eliminate) camera shake that is most noticeable on telephoto photos.
This will give you noticeably better results when recording from aircraft.
The two most common types of image stabilization in use are:
• Electronic Image Stabilization (EIS) uses one of two methods to reduce
shake. The digital method increases the size of the image by digitally
"zooming" in on the image so that it is larger than the CCD; this
decreases picture resolution somewhat. The other method uses
electronic motion sensors to sense the motion of the camera; this may
slow the autofocus function and may cause a slight “jump” at the
beginning of a scan.
• Optical Image Stabilization (OIS) uses a lens/prism assembly moves in
opposition to camera shaking. This results in little or no change to
camcorder efficiency or quality.
Although image stabilization adds to the cost of the camcorder, it is a very
valuable feature. If you have a choice, choose OIS.
4.1.7 Autofocus
Although autofocus (AF) lenses can be a help in following moving subjects or
filming a target from a moving aircraft, you will encounter problems unless you
fully understand how they work.
Most autofocus devices assume that the area you want in sharp focus is in
the center of the picture. If the area you want to focus on does not remain in the
center of the frame, autofocus is not useful. Some camcorders allow you to
center the subject matter in the autofocus zone and then lock the autofocus on
this area; you can then reframe the scene for the best composition.
Autofocus systems have other weaknesses. Most can be fooled by
reflections and by flat areas with no detail. Most autofocus systems also have
trouble determining accurate focus when shooting through glass (e.g., an aircraft
window). And, finally, autofocus devices (especially under low light) can keep
readjusting or searching for focus as you shoot, which can be quite distracting.
However, for most CAP uses autofocus is a valuable feature. Just be sure to
shoot through an open window and keep the target centered in the frame. [Note:
Many camcorders have an ‘infinity focus’ feature that helps alleviate this problem.]
4.1.8 Video Resolution
The term resolution refers to the ability of an imaging system to capture fine
details; the higher the resolution, the sharper the photos. In digital video,
resolution is calculated differently than it is for digital cameras.
The vertical resolution of a digital video image is determined by the number of
scan lines in the image. The horizontal resolution is the rate at which the moving
beam can turn on and off to paint "dots" of color on the screen (this can happen
only so fast because it takes time for the circuits to switch from black to white).