Originally Posted by David Susilo
and that's my point exactly. 4K projectors have 2x zoom at f/1.8 or f/2.0 (depending on the projector) and to manufacture a lens with that large of an aperture with 2x zoom is insanely expensive. My 70-200 f/2.8L lens is $2500 (it was $3000+ a decade ago)/ So how a good quality 4K projector can be priced below $4000 I don't think it's going to happen. Even to this day, the cheapest HD projector with good glass lens still cost $5,000 street (at least in Canada).
You can't really use prices of photographic lenses as an argument that projector lenses for 4K projectors, that are good enough, will be prohibiting expensive.
Prices on optics doesn't really reflect the cost of manufacturing good quality optics.
In this day and age, with computer simulated optical designs and laser guided robotic machines grinding and building optics, they don't need to be so epxpensive as the prices of Camera lenses seems to show.
Photo lenses are priced based on what the manufacturer believe they can get for them and how much they can hype the quality. Photographers are gullible people.
Lets look at some examples of Lens prices.
Canon EF 50mm f/1.4 USM Lens is at $399.99 reckoned optically as almost as good as the Canon EF 50mm f/1.2L USM Lens at $1,619.00, and the same optics that is in the 50mm L, is probably in the Canon CN-E 50mm T1.3 L F Cine Lens at $4700.
The largest difference between these three lenses with such large price difference are the lens mechanics.
They are still cheap compared to the Arri / Zeiss 50mm LDS Master Prime T1.3 at $22,850, which is not much sharper at all.
The Canon EF 70-200mm f/2.8 L Mark II is reckoned as one of the sharpest Canon lenses and maybe the sharpest zoom ever, even compared to Cine Zooms.
A Fujinon HK7.5x24 24-180mm T2.6 Premier PL 4K+ Cine Zoom cost $87,300.
Anybody really think that the cost of manufacturing the optics of the Fujinon is really reflected in the price compared to the Canon?
Sigma make a really sharp 18-35mm f/1.8 and sell it for $799, while Canon want around $1200 for their EF-S 17-55mm f/2.8 IS USM and Nikon 17-55mm ƒ/2.8G ED-IF AF-S DX takes the "high" road at whopping $1400.
When they find a solution to using RGB lasers in projectors they can also benefit by using smaller diameter optics that don't need to have larger aperture than f/4 - f/6, which will lower the cost of manufacturing optics significantly.
I hope the projector manufacturers are wise enough to keep the imagine chips large as that will benefit the resolution quality.
At least with 4K you are guarantied to get at least a minimum of 2 megapixel resolution, something you don't get with 2K~HD projectors.
For the future, if the rumour that printing OLED has had a breakthrough recently, in ten years time we might be able to throw out our projectors and just buy a roll of OLED screen with 500PPI and mount it.