Our take
BenQ's TH685 is a source-verified Full HD gaming and home theater model with 3500 ANSI lumens and a 1.3× conventional zoom lens. It offers a clearer brightness basis than several other projectors in this batch, but still needs a measured room and external source plan.
A conventional home theater or gaming setup with enough throw distance and external HDMI sources.
It is not a close-wall UST model, native 4K projector, battery device, or app-streaming replacement; plan for a lamp and an external player.
Pros & cons
What could work for you, and what to consider before buying.
What works in its favor
- BenQ specifies native 1920 × 1080 DLP imaging and 3500 ANSI lumens.
- The 1.127–1.46:1 throw ratio and 1.3× zoom support several conventional room layouts.
- BenQ positions the model for home entertainment and gaming.
What to weigh up
- Its native panel is Full HD rather than 4K.
- A lamp-based design adds a condition and replacement-lamp check for used examples.
- No built-in streaming platform or lens shift is documented in the reviewed specifications.
The key details
| Model covered | TH685 |
|---|---|
| Image format | Native Full HD 1920 × 1080 DLP |
| Rated light output | 3500 ANSI lumens |
| Placement | 1.127–1.46:1 throw; 1.3× manual zoom |
Performance figures are manufacturer claims. Source checked October 5, 2026. Regional models and included accessories can differ.
What the features mean for you
Native Full HD gives the TH685 a clear home role
BenQ specifies native 1920 × 1080 resolution through a DLP imaging system and positions the TH685 for home entertainment and gaming. This makes it a straightforward match for Full HD consoles, movies, and sports where a Full HD panel is sufficient. A 4K input or marketing badge should not be mistaken for a native 4K imaging device; this model's saved specification is explicit about 1080p. Source timing, screen size, focus, and viewing distance still affect the visible result. If most of your content is 4K and you sit close to a very large screen, compare a model with documented higher native resolution. For standard HD use, its format is easier to evaluate.
3500 ANSI lumens is a defined comparison point
The TH685's manufacturer page lists 3500 ANSI lumens, which gives buyers a stated measurement basis rather than an unlabeled lumen headline. That number can help screen options, but it does not guarantee a bright image under every room condition. Image size, lamp mode, screen surface, room light, and the condition of the specific lamp all matter. Used or renewed units should be checked for lamp hours and uniformity, and a seller demonstration should use an image size close to the planned setup. If the room is bright, compare actual screen and ambient-light constraints as well. The ANSI label is useful evidence, not an independent measurement of an individual projector.
Conventional placement leaves room to plan
BenQ gives a 1.127–1.46:1 throw ratio and 1.3× manual zoom. This is a conventional lens: measure the distance from the projector to the target screen width before choosing a shelf or mount. The zoom ring supplies bounded optical adjustment, while digital correction cannot relocate the projector or add lens shift. BenQ lists lens shift as unavailable for this model, so vertical and horizontal mount placement deserve attention. Check the projected image height, ceiling clearance, cable path, and seating before installation. The TH685's geometry is flexible enough for several rooms, but it is not a substitute for a room measurement and cannot solve a close-wall constraint.
Build an external source chain for apps and games
The TH685 accepts external sources, which is natural for a console-oriented home setup. BenQ's saved materials do not document integrated streaming apps, so connect a console, media player, or streaming device for services and games. Confirm resolution and refresh behavior for the exact source and choose an audio route that fits the room. An external player provides its own service updates and can be replaced separately, but adds another device and cable. The projector's game-oriented positioning does not mean the streaming platform is built in. Check available HDMI ports, remote operation, and sound-system connections before installing. For a fixed theater, planning the whole source and audio chain often matters as much as the projector shortlist.
A lamp projector calls for inspection
A TH685 can be an appealing home model when Full HD and the documented ANSI figure match the plan, but each used projector has its own lamp and hardware history. Verify the model label, lamp hours, cold start, fan and color-wheel sound, image focus at the corners, uniformity, ports, remote, and shutdown sequence. The manual explains operation; it cannot certify the state of a seller's unit. Check that the throw distance works before buying a mount and that the projector has ventilation space. This is a feature-based comparison, not a personal picture-quality test or a statement about current listings. Buyers should weigh the lamp's remaining life with the purchase price and service needs.
What else to compare
For UHD output at close-wall placement, compare Optoma CinemaX D2 Smart; for documented native 4K and conventional throw, compare AAXA 4K1 while noting its non-ANSI light-output figure.
Before you buy
Is the TH685 native 4K?
No. BenQ lists native Full HD 1920 × 1080, although higher-resolution input support is a separate issue.
What is its ANSI rating?
BenQ specifies 3500 ANSI lumens for the TH685.
Can it sit right next to the screen?
No. Its 1.127–1.46:1 ratio is conventional throw and requires a measured projector-to-screen distance.
Where can I check the current price?
Use the Amazon link for current offers. Check the exact model, seller, product condition, delivery, and return terms. This page does not display a live price or confirm stock.
Sources & review basis
We use the following manufacturer documentation for the product features above. Our suitability notes and buying advice are editorial judgments based on those features, not measured performance results.
- BenQ TH685 specifications and user manual ↗ — checked October 5, 2026.
- BenQ TH685 official specifications ↗ — checked October 5, 2026.
- BenQ TH685 user manual ↗ — checked October 5, 2026.
The decision
The TH685 is a strong fit for a measured Full HD gaming room when 3500 ANSI lumens and conventional placement satisfy the actual screen and lamp condition.
Is it the right fit?
Check the exact model and today’s offers on Amazon.