The Knowhow
3D projectors use either active or passive 3D. You can enjoy 3D films on both designs, but the accessories they come with are slightly different and the quality of the projected image varies.
| PASSIVE 3D | ACTIVE 3D | |
|---|---|---|
| MAIN USE | Mainly used commercially for cinemas, businesses and classrooms | Mainly used in the home for 3D films and gaming |
| No passive projectors are currently on the market for home use in the UK, but you can buy passive 3D TVs, or convert active 3D to passive 3D by using a special adaptor | ||
| 3D GLASSES | Don't need to be re-charged | Need re-charging (on average once every 40 hours) |
| TECHNOLOGY USED | Originally: Anaglyph 3D. The original passive (anaglyph) proejctors aren't used much these days - they were the ones with the blue and red-lensed 3D specs. They offered a good, low-cost way to show 3D images to a large audience, but the colour definition was poor. | Active shutter: Uses a high-speed projector, along with shuttered glasses (the lenses interact with the projector, opening and closing on command) |
| The latest: Polarised lenses: The latest passive 3D uses new technology - polarized lenses - to show better-quality 3D. It's the technology of choice for 3D screenings at the cinema, but you won't find it on home projectors, because it needs two projectors to work | Integrated colour filter: Uses a colour filter close to the projector lamp. | |
| ADVANTAGES | Extra pairs of glasses are inexpensive | Higher screen resolution (achieved by showing the images in sequence, rather than at the same time) |
| Glasses are lightweight and don't need to be charged | Can also be converted to passive 3D using TruD technology. | |
| No flickering effect with polarised lenses (the viewer doesn't lose the 3D image) | More flexible - offers 2D as well as 3D viewing on the same screen. | |
| Brighter image | Any matte white projector screen can be used, even a blank wall. | |
| DISDVANTAGES | Lower image resolution - one image has less than half the resolution of shutter 3D (because the left and right eyes both see a flat image of 540 lines of resolution at the same time), but when the two images are combined, the resolution for both images is high (1080 resolution) | The 3D specs need re-charging |
| Needs a special silver screen, which can only be used for 3D media | Glasses can be quite heavy and clunky to wear, but there are lightweight designs available | |
| Glasses are expensive to replace | ||
| Dimmer screen brightness | ||
| Shuttered 3D sometimes reveals the two separate images to the viewer, losing the 3D illusion (the 'judder' effect). It's a syncing problem between the Bluetooth commands opening and shutting the glasses, and the glasses receiving the commands. | ||
| The judder effect tends to happen in high-speed scenes, so if you want a 3D projector to screen films with fast car chases or action-packing gaming, don't choose a model which uses active shutter technology. | ||
| PRICE RANGE | Passive projectors are currently only available commercially in the UK (because of the high cost involved), but with Tru3D you can convert your active 3D projector to passive 3D. Instead of using bulky active 3D specs, you can use the lightweight passive 3D glasses. | Projector: £250 - £2000 |
| The adaptor costs: £1,000 - £2,000 | Glasses: £100 | |
| With the adaptor, you will also need a silver screen: £500 - £2,000, but if this exceeds your budget, you can buy polarising silver paint instead. This is a good DIY alternative for a mere £70 - £100. | Screen: £75 - £200 | |
| Lamp replacement: £70 - £200 (every 3000 hours, depending on how often you use your projector) | ||
| BRANDS | Mitsubishi | LG (TV only) |
| Panasonic | RED 1 (expected 2011) | |
| Samsung | Tru3D (adaptor; converts to passive 3D) | |
| Sharp |
