BenQ TH685p 3,500-Lumen Full HD Projector with 8.3 ms Input Lag for Gaming and Home Theater

BenQ TH685p – Full HD Gaming Projector with 8.3 ms Input Lag and 3,500 Lumens

The BenQ TH685p is aimed at gamers and movie fans who want a large image with low input lag. With 8.3 ms input lag at Full HD and a 120 Hz refresh rate, the projector reacts faster than most gaming displays – PS5, Xbox Series X and PC gamers benefit from this responsiveness on the screen. 3,500 lumens ensure a clearly visible image even in a living room with ambient light, while HDR10 and HLG bring streaming content to the projection surface with noticeably more depth and contrast.

Benefits at a glance

• 8.3 ms input lag at Full HD – excellent for action, FPS and racing
• 120 Hz – smooth display even in fast-paced game scenes
• 3,500 lumens – bright image even in dimmed living room light
• HDR10 and HLG – more depth and contrast for streaming and live TV
• Vertical lens shift (5%) – makes setup easier without keystone
• 3D playback via DLP Link – compatible with 3D glasses
• SmartEco mode – automatically extends the lamp life
• Only 2.79 kg – compact and easy to move

Applications: What the BenQ TH685p is suitable for

Gaming sessions with PS5, Xbox and PC

8.3 ms input lag makes the TH685p the clear choice for competitive players: shooters, racing games and action genres run without noticeable delay. The 120 Hz output ensures smooth images during fast movements – a different experience on a 100" image diagonal (approx. 254 cm) than on a 55-inch TV. Anyone who leaves digital keystone correction active should bear in mind that this can slightly increase the input lag – a physically correct setup brings out the full potential.

Movie and series nights with HDR

With 3,500 lumens and a contrast ratio of 10,000:1, the TH685p delivers a clearly visible image even in a living room with ambient light – for a fully darkened home cinema, 3,500 lumens are easily sufficient for image diagonals well over 100". HDR10 and HLG are supported: streaming content from Netflix, Disney+ or Amazon Prime appears with more headroom for brightness and depth of contrast than in SDR mode. LumiExpert automatically adjusts the brightness to the ambient light and protects the eyes during long sessions.

Football and sports in the living room

3,500 lumens are sufficient to deliver a sufficiently bright image even with half-closed blinds. The integrated 5 W speaker bridges spontaneous game nights without an external sound system – for a full stadium atmosphere, a soundbar via the 3.5 mm jack output is recommended.

Image quality

The TH685p uses DLP technology with a 0.48" DMD chip and a native Full HD resolution of 1,920 × 1,080 pixels. DLP projectors inherently deliver excellent motion sharpness and high ANSI contrast – ideal for fast game sequences and action-packed movie scenes. The contrast is 10,000:1 and brings black with clear contours to the screen even in dark scenes.

HDR10 and HLG expand the brightness and color space compared to standard SDR content. HDR10 is the most widely used HDR standard for Ultra HD Blu-ray and the major streaming platforms; HLG (Hybrid Log-Gamma) is optimized for TV broadcasts and is backward compatible with SDR devices – a plus for live sports and public broadcasting content.

Connections

• HDMI 2.0: 2 inputs – to keep game consoles, streaming sticks or laptops connected at the same time
• USB-A: 1 port – for powering a streaming stick (e.g. Fire TV Stick or Chromecast)
• 3.5 mm jack: audio output for soundbar or headphones
• LAN port (RJ-45): for a stable network connection
• RS-232: control output for external automation systems

Gaming performance

With 8.3 ms input lag, the TH685p is among the fastest Full HD projectors in the consumer market – this value is excellent and is also suitable for competitive shooters and racing games. The native 120 Hz playback benefits players who need smooth motion display. VRR and ALLM are not integrated; consoles such as PS5 or Xbox Series X can still be connected directly via HDMI 2.0 and benefit from the low lag in the projector's game mode.

Sound

The integrated 5 W mono speaker provides enough for an uncomplicated game night or sports night without external equipment. For a real home cinema experience, a soundbar or AV receiver is worth it: The 3.5 mm jack output transmits the audio signal losslessly to any external system.

Smart features & Streaming

The TH685p does not have an integrated smart OS. External media players such as Apple TV, Amazon Fire TV or Chromecast with Google TV can be connected via HDMI – the USB-A port directly powers compact streaming sticks, eliminating the need for a power supply adapter. For AirPlay, Miracast and Google Cast in one device, the EZCast Pro Dongle II is available as a casting receiver – no app installation on the projector is necessary, with the smartphone serving as a remote control.

Setup, projection & scope of delivery

The BenQ TH685p supports table, ceiling and rear projection setups. The housing measures 312 × 225 × 110 mm (W × D × H) and weighs 2.79 kg – light enough to move easily between rooms. When ceiling mounted, the projector hangs upside down; the 5% vertical lens shift allows for slight optical image correction without quality loss from keystone. Allow approx. 10–15 cm behind the housing for cable connections.

With a 1.3× zoom lens and a throw ratio of 1.13–1.46:1, the following applies for common image sizes:

The calculated projection distances are based on the manufacturer's throw ratio and serve as guidelines.

With 3,500 lumens, an ALR screen (Ambient Light Rejecting) is recommended for rooms with ambient light, as it absorbs ambient light and noticeably improves contrast. In a fully darkened home cinema, a classic gain-1.0 screen delivers the best color reproduction.

Scope of delivery: Remote control, power cable, batteries

For ceiling mounting, we recommend a suitable projector ceiling mount from our range.

Light source & operation

The TH685p uses a UHP lamp. In SmartEco mode, BenQ's automatic system detects dark scenes and automatically reduces the lamp power – this extends the lifespan without having to manually adjust the settings. The BenQ Instant-Off function allows the device to be disconnected from the power supply immediately after switching it off, without having to wait for the cooling fan to stop.

Anyone who wants to completely avoid changing lamps will find our laser projectors with up to 30,000 hours of lifespan – maintenance-free and without replacement lamp costs.

Operating noise: In Normal mode, the TH685p generates 35 dB – noticeable in a home cinema, especially during quiet movie scenes. In Eco mode, the value drops to 29 dB, which is pleasantly quiet and barely noticeable even during quiet passages. For an optimal cinema experience, Eco mode is worth it if the reduced brightness is sufficient for the room.

Power consumption: 297 W (Normal mode), 206 W (Eco mode), 0.5 W (standby). Replacement lamp (BenQ part no.: 5J.JKX05.001)

Who the BenQ TH685p is suitable for

• Gamers with a PS5, Xbox Series X or gaming PC who want fast response times on a large screen
• Movie fans in the living room who want to experience HDR streaming on 100"
• Users who prefer a flexibly positionable projector without a complicated installation
• Sports fans who want to host spontaneous game nights without major setup effort

Anyone considering longer runtimes without changing lamps, optional lens shift for greater setup flexibility or native 4K content will find the next level of home cinema projectors with lens shift – for example in our laser projector category.

Have you thought of everything?

• Ceiling mount – for a stable upside-down fixed installation
• HDMI cable – for 4K-capable signal transmission, certified according to HDMI 2.0
• EZCast Pro Dongle II – casting receiver for AirPlay, Miracast and Google Cast in one

Conclusion: BenQ TH685p

The BenQ TH685p delivers what gaming projectors in the Full HD segment must promise: 8.3 ms input lag, 120 Hz and 3,500 lumens – that is enough for a bright, responsive image on a large screen. Anyone who wants to experience streaming content with HDR on more than a 100" image diagonal will get a solid, compact device here without unnecessary complexity. Our team is happy to help with setup advice for the screen, mount and cables: Request advice now.