Why are resolutions on projectors so bad and expensive?

jn77

Distinguished
Feb 14, 2007
587
0
18,990
I have been looking a projectors for a while and traditional projectors of any decent quality are at least $1499. But their resolution stinks.

Then it looked like a new market appeared..... the Pico projectors.... Less than $499, usually small form factor, some even fit in pockets, can be mounted to cell phones (Moto), etc.

But then there is the hangup. Screen resolution and maybe a close second is the lumen output.

I have a vague idea how projectors work but do not understand the technical details.

What I am looking for is a "Native" not some algorithm that "fakes" true 4K resolution in an affordable projector with decent lumen output.

It seems like what ever TFT/ LCD panel they use to pass the light source though is so prohibitively expensive that no one can built, mass market and sell a sub $2999 4k projector......

I mean that LCD panel cannot cost that much to produce. They are just greedy (Insert words here).

I mean, monitors have gotten so cheap over the years, I remember when a 24 inch Sony wide screen CRT for CAD work in the 1990's was $4000 and now you can get LED/LCD 24 inch monitors for under $300.

So what is the deal with projectors? It's like they are asking for 10,000% profit margin on them. There is no way they cost as much as they do.

Even the lenses are not that expensive.... My DSLR lenses cost way more than the cheap crappy lenses do that they put on projectors.
 
Solution
A typical monitor backlight is about 10-15 Watts, 30 Watts max. A 20+ inch diagonal panel means that heat is spread so it's around 0.1 Watt per square inch.

A projector's backlight is typically about 1200-1500 Watts. All that power and heat is sent through an LCD an inch or two diagonal. That means you're talking about 250-1000 Watts per square inch. It's a much harder problem to design a panel system which can withstand that amount of light and heat. It's partitioned to try to isolate the heat from the light before it ever hits the LCDs (there are 3 LCDs for the better projectors btw, to avoid throwing away 67% of the light like monitors do).

There's also economies of scale. LCD monitor sales are close to 100 million per year...
A typical monitor backlight is about 10-15 Watts, 30 Watts max. A 20+ inch diagonal panel means that heat is spread so it's around 0.1 Watt per square inch.

A projector's backlight is typically about 1200-1500 Watts. All that power and heat is sent through an LCD an inch or two diagonal. That means you're talking about 250-1000 Watts per square inch. It's a much harder problem to design a panel system which can withstand that amount of light and heat. It's partitioned to try to isolate the heat from the light before it ever hits the LCDs (there are 3 LCDs for the better projectors btw, to avoid throwing away 67% of the light like monitors do).

There's also economies of scale. LCD monitor sales are close to 100 million per year. Projector sales are around 1 million per year. So you can amortize monitor design and engineering costs over 100x as many units. If it costs $500,000 to design a monitor and you sell 100,000 units, the design costs add $5 to the cost of each monitor. If it costs $500,000 to deign a projector and you sell 1,000 of them, the design costs work out to $500 per projector.

The lenses are more expensive than your camera lenses too. Your camera lens only has to take a spherical world view and focus it onto a flat sensor. If the corners of the focal plane don't exactly fall in a plane, it's ok because usually what you're photographing doesn't fall exactly in a plane. Some field curvature is acceptable.

https://en.wikipedia.org/wiki/Petzval_field_curvature

Projectors don't have that luxury. They have to take an image on a perfectly flat sensor and project it onto a perfectly flat screen. There can be absolutely no field curvature. The large image size also means there's less tolerance for other common aberrations like chromatic aberration (smearing of colors near the edges and corners).
 
Solution