Optoma GT1080HDR vs BenQ TH685: short throw face-off

A short throw projector can create a cinematic picture without the deep room needed by a conventional home theatre projector. The Optoma GT1080HDR and BenQ TH685 both suit lounge rooms, rented spaces and Australian homes where every metre of sofa-to-wall distance counts, but they prioritise different features. One focuses on straightforward gaming value, while the other adds higher brightness, faster refresh rates and built-in streaming.

The Optoma GT1080HDR is a 1080p gaming projector with a 120Hz refresh rate, 8.3ms input lag and a 0.65:1 throw ratio. The BenQ TH685 also has a native 1920x1080 resolution, but adds 4K pixel-shifting, a 240Hz gaming mode, 4.4ms input lag and a smart-TV platform. Those differences make the TH685 more versatile for mixed entertainment, while the Optoma can be the more economical choice for a dedicated gaming setup.

The core difference at a glance

Both projectors use lamp-based DLP technology and produce a 1920x1080 image. Their short throw lenses are also similar in principle: the GT1080HDR has a 0.65:1 throw ratio, while the TH685 uses 0.69:1. In practical terms, both can place a large picture relatively close to the screen, although their zoom controls, lens positions and exact image dimensions differ.

Optoma rates the GT1080HDR at 3,200 lumens, while BenQ quotes 3,500 ANSI lumens for the TH685. Different brightness measurement methods make these figures imperfectly comparable, but the BenQ has the stronger published specification. Its smart-TV features also distinguish it clearly from the Optoma, which needs an external streaming device or a connected set-top box.

Gaming speed and picture quality

The TH685 is the stronger choice for demanding console gamers. It supports 1080p gaming at 240Hz with an advertised input lag of 4.4ms, giving it plenty of headroom for fast shooters, sports games and competitive multiplayer. The GT1080HDR runs at up to 120Hz with 8.3ms input lag. That remains perfectly responsive for most players, including a Friday night FIFA session with mates, although it is less future-proof than the BenQ.

The TH685 accepts 4K signals and creates enhanced 4K images using pixel shifting, while the GT1080HDR remains a straightforward 1080p projector. The enhancement can make supported content appear more detailed, particularly on a large screen, but it does not give either model native 4K imaging. Gamers should choose according to their console output and priorities: the BenQ offers more processing flexibility, while the Optoma delivers the core experience without a premium specification sheet.

Both projectors support high refresh rates, but neither combines native 4K with ultra-fast gaming. HDR compatibility and strong colour reproduction also require suitable source material to have much impact. For sport, DLP’s sharp image and low smear are useful, but the picture should be judged in a darkened room rather than by specification alone. A clean 1080p image with sensible settings can look more convincing than a brighter picture carrying too much motion processing.

Size, throw distance and screen placement

The TH685 can display a 100-inch image at approximately 1.3 metres from the screen, while the GT1080HDR typically needs around 1.4 metres for a similar width. The difference is modest, but it can determine whether the projector fits behind a sofa, on a narrow console or beneath a wall-mounted television. Use each model’s throw-distance chart before buying, and measure from the intended lens position rather than from the projector’s front edge.

This is particularly relevant in Sydney and Melbourne terraces and compact apartments, where a standard throw projector may sit too far from the available screen wall. A 100-inch picture is usually practical for a mixed-use living room, while 120 inches works well for a dedicated cinema space or a large dedicated screen. Short throw does not mean ultra short throw: these models still need meaningful separation from the wall and sufficient clearance for vents, cables and manual adjustment.

Avoid relying on heavy keystone correction to force an awkward installation. It reduces the usable image area and can introduce brightness and sharpness compromises. A level projector, properly positioned lens and correctly sized screen will produce the cleanest result. If the room is too shallow for either model, a smaller screen or a different mounting arrangement may be a better buying decision.

Setup, streaming and the Australian home

The TH685’s integrated Google TV platform provides access to major streaming services without another device taking up an HDMI port. It suits households wanting Netflix, Disney+ or other apps alongside console gaming, and casting can handle casual viewing from compatible phones. The Optoma is less demanding in some respects because it can be controlled through whatever streaming box or console the household already owns, though that extra equipment adds clutter and another remote.

Australian mains electricity runs at 220–240V, and both projectors are sold locally with suitable power leads and accessories. Check the supplied items with an authorised Australian retailer, particularly if buying an imported unit. Local warranty support and GST-inclusive pricing are also worth comparing, since grey-market stock may not carry the same consumer protections as a locally supplied model.

Strong daylight and Australian summer heat can make a living room less cinema-like than expected. Even the brighter TH685 works best with curtains closed and direct sunlight removed from the screen. An ambient-light-rejecting screen can help in a bright space, but it costs more and only solves part of the problem. Neither projector’s built-in speakers will fully replace a soundbar for commentary, so existing television audio may be the practical choice for match nights.

Choosing the right projector for your room

Choose the GT1080HDR when gaming at 1080p is the priority, the budget is fixed and the household already has a streaming device. Its 120Hz mode and 8.3ms lag are suitable for competitive play, and its short throw capability reduces the distance required for a large screen. It offers the essential features of this pairing with fewer smart-TV extras to configure, update or eventually replace.

Choose the TH685 when the projector will handle more than gaming. Its higher gaming refresh rate, lower input lag, enhanced 4K processing and greater published brightness suit a mixed family setup, larger displays and regular movie nights. A 100-inch or 120-inch projected footy match can look outstanding on a properly adjusted screen, provided the room is dark enough and the sound comes from a capable system.

Measure the intended screen and available lens-to-screen distance, then compare current GST-inclusive prices from authorised Australian retailers with clear local warranty terms. Buy the Optoma for focused 1080p gaming value, or choose the BenQ for the more complete feature set—and bring the big-screen match night home.