"Dave Plowman (News)" wrote in message
...
In article ,
Calvin Sambrook wrote:
Er, no. While I wouldn't defend individual relamp prices as I don't
know the specifics of individual projectors I do know that lamp
technology in DLP is nothing like that used in other projector
technologies. DLP demands really short arcs and very precise alignment
if the image on screen is going to look good. Manufacturers go to a
lot of trouble to get it right and if you're prepared to spend £10k on
a projector in order to get a superb image why on earth would you ruin
it at relamp time?

Well, I have a Sagem DLP rear projector, and a new lamp for that costs
nothing like 600 quid. And surely any type of projector requires both a
precision light source and optics to give the best results?


Yes and no, DLP requires much shorter arc lamps than LCD et al, it's
fundamental to the design. As the arc gets shorter the other complicating
factors get harder to handle so the cost goes up. If you're using a small,
cheap DLP, the sort you might buy in the high street, then the power is
relatively low which makes things significantly easier, the complexity rises
exponentially with power. Compare your friend's projector power consumption
with yours, most of the power goes into the lamp and very little comes out
the lens, then think what's got to happen to keep that internals of the lamp
cool.
With cheaper projectors you're expectations are lower and tolerance to
imperfections higher. You probably feel pleased to have saved a few (lots
of) £s even if the image isn't quite as good. Indeed you may not even
notice.
If you've paid £10k then presumably you want a big, bright image and you
care about the image quality. Things like roll-off where the image gets
darker towards the edges because the lamp isn't aligned quite correctly and
loss of brightness are probably not acceptable after a relamp, certainly not
if you buy an OEM part.

I guess it's a bit like tyres on a car. I don't buy expensive cars, when it
comes to replacing tyres I tend to buy cheap as I'm not looking to get the
last little bit of performance and I can tolerate quite a lack of refinement
if I save cash.
You might buy an expensive performance sports car in which case you'd
probably be quite prepared to pay for expensive tyres in order to keep the
benefits which go with them. Putting cheap tyres on means it doesn't
perform as well so why spend the money on it in the first place?