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Answer: |
All
Digital type projectors and Plasmas have a native rate
resolution ñ that is, exactly how many pixels are
built into the display device that can be used in the
projected image. Today, the typical native rates for
these projectors are 800 x 600 and 1024 x 768. The
higher end products run at 1280 x 1024, while the DILA
(resolution champions) start at 1365 x 1024 and soon
will be available at an astonishing 2048 x 1600 (at an
equally astonishing price).
If the input source differs
in resolution from the projectorís native rate, then
the projector uses a process internally, called
ìscalingî. This is a process, by which the projector
automatically extrapolates, line by line, additional
picture information (if the input resolution is lower
than the native rate) through algorithms and then is
able to address all pixels available, giving you a full,
seamless picture. This process is greatly beneficial on
standard video, yielding a high quality, no scan-line
picture. If the input resolution is higher than the
native rate, the projector again uses scaling to perform
ìcompressionî, or a mathematical elimination of
pixels. If the input resolution is significantly higher
than the native rate, the image starts to deteriorate
badly, so it is wise to always use a display technology
that has the same, or nearly the same native rate as the
highest rate you intend to display.
CRT projectors, on the other hand, do not suffer
from a native rate restriction by virtue of their analog
properties. Since they use a scanning beam to sweep
across a phosphor coating to produce light, they
inherently are true multi-sync display devices. This
simply means that, as long as the electronics are up to
the task, the CRT projector can display any resolution
thrown at it without the need for any kind of scaling.
Of course, all CRT projectors have a resolution limit
(generally 1280 x 1024 for 7î CRTís, 1600 x 1280 for
9îers), and when input with a signal that exceeds this
limit, the projector naturally eliminates pixel
information due to the scanning beamís inability to
turn on/off fast enough and the phosphorís fade
characteristics. This results in a generally good but
softer picture lacking the extreme detail that a higher
quality projector would reproduce. CRT projectors also
benefit from artifact free performance, whereas all the
digital projectors will create image artifacts in the
process of scaling (some, very annoying). |
