We've evaluated dozens of different projectors over the years for use
here on campus and here are some of the pertinent issues:
- Globe life and Cost: the globes usually only last 1500 hrs or so
and are average from $250 to $500 to replace. Also, the brightness
generally diminishes over the life of the globe, so within a few
hundred hours the brightness may be down by 30%. If you only use the
projector for special occasions, this may not be a big issue, but if
you plan to watch general TV through it, the hours can mount up
pretty quickly.
- Resolution & Inputs: make sure the Data projector supports the
highest resolution and interface connection that you wish your DVD
player to output. ie. Avoid Composite-only projectors. S-VHS goes
up to 768 x 576 on a PAL display while Component (three RCA (or BNC)
plugs labelled Y,Pr,Pb) connected to a 1080i HDTV display can output
up to 1920 x 1080. Note that DVDs are limited to a maximum of 540
scan lines so you won't achieve this resolution but it will give a
higher quality signal than S-VHS.
Also note a progressive Scan DVD player should give higher quality
output than an interlaced output DVD player connected to a data
projector. With a projector with a resolution of 800 x 600 or more,
you should get a reasonable reproduction.
- Space Considerations: note the distance particular projectors need
to be from the screen for a given size on screen. Some lounge rooms
may be too small for the desired size of image from some projectors.
Also bear in mind the problem of the audience obstructing the
projected image which isn't a problem with big-screen TVs.
- Projection Screen: If ambient light is a problem (you can't darken
the venue enough) you might like to invest in a higher quality
projection screen to boost the brightness of the projected image. A
glass-beaded screen can give a significant increase in brightness
while not restricting the viewing angle appreciably. If you need to
boost the brightness by several orders of magnitude and you don't
mind the necessity of sitting directly in front of the screen within
a fairly limited viewing angle you could purchase a Day-light screen
(note these are rigid and curved and cost a lot!).
Hope this helps.
-Mart
At 2:20 PM +0800 14/1/03, Phillip Arena wrote:
Hello all and hope you managed some sort of break (holiday variety)
over the new years. I'm looking for advice on watching DVDs (from a
DVD player, not a PC/Mac) via a projector compared to widescreen tv
etc. Any advice on quality etc would be greatly appreciated. Is it
worth buying such a projector (which I can also use for data
presentations)? I have no idea on the presentation quality for DVDs
and have only used marginally good machines at work for data
presentation. Recommended brands would be nice to know also. Thanks
again.
--
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Martin Hill mailto:[EMAIL PROTECTED]
Multimedia Consultant Home Page: http://mart.curtin.edu.au
Educational & Online Technologies, Information Services, Curtin University
Mobile: 0417-967-969 wk: (08)9266-3101 Fax: (08)9266-3826
