TK705STi

Quick verdict: The BenQ TK705STi brings smart 4K UHD entertainment to a shallower room, where putting a projector farther back simply isn't practical. It pairs Google TV, 4LED illumination and a manufacturer-rated 3,000 ANSI lumens with a fixed 0.8 throw ratio. That lens is its defining advantage over the standard TK705i, and also its main constraint: you get a large image at closer range, but very little optical flexibility if the projector cannot sit at the correct distance.

Best for: A smaller living room or gaming space where a conventional projector sits too far back, but a true ultra-short-throw system would be excessive.

Skip it if: You need a fixed screen and projector shelf that demand optical zoom, want a projector almost touching the screen wall, or expect native 4K120 output from the HDMI 2.1 label.

Who it fits

The TK705STi is made for the buyer who wants to turn a modest room into a big-screen movie or gaming space. You have a wall where the picture belongs, but the sofa and furniture leave little practical room for a standard-throw projector. Its short lens gives you another placement option without switching to the very different cabinet-and-ALR-screen world of ultra-short throw.

BenQ also offers the TK705i. The two are closely related in brightness, streaming software, light engine and headline gaming claims. Their difference isn't primarily an image-quality contest. The TK705i has a 1.0–1.3 throw ratio and 1.3x optical zoom; the TK705STi uses a fixed 0.8 ratio. Choose between them based on the room.

This product is not battery powered. It requires a mains outlet and space to vent heat. It can be moved occasionally, but a fixed-throw projector is happier with a stable position you can return to accurately.

What changes the decision

The 0.8 throw ratio is the main reason to buy

BenQ specifies a 0.8:1 fixed throw ratio. A typical 100-inch 16:9 screen is around 87 inches wide, so multiplying that width by 0.8 gives approximately 5.8 feet from the lens to the screen. This is an illustrative planning calculation, not guaranteed mounting clearance. The actual image, chassis size and offset should be checked with the manufacturer's own calculator.

Compare that with the standard TK705i, which would need roughly 7.3–9.4 feet for a similarly sized image within its zoom range. In a small room, saving that distance can be the difference between a practical projector and an awkward one.

The fixed lens is a trade-off. The TK705STi doesn't provide an optical zoom ring to rescue an unsuitable mounting distance. If you mount it too close or too far away, the image size may be wrong. Digital zoom or keystone can change the displayed picture, but such changes aren't the equivalent of optical flexibility and may affect detail.

Before you buy, mark the projector's real footprint on the floor or shelf—not just the lens position. Include its full depth, ventilation space and power-cord path. A projector six feet from the wall can make a great big picture and still be a terrible roommate if it blocks the doorway or the main walkway.

Short throw isn't the same as ultra-short throw

A UST projector such as the Hisense PX3-PRO sits near the wall and projects up at a steep angle to a dedicated screen. The TK705STi sends its image from several feet away, using conventional projector geometry.

That means you may not need a UST-specific ambient-light-rejecting screen or a perfectly level console directly beneath the picture. But you still need a clear light path and enough room for the body to sit safely. Placing the unit only inches from the screen wall won't create a giant picture.

A ceiling mount can solve furniture conflicts, but its position must be calculated carefully. BenQ's stated full-height offset and automatic alignment tools are specifications for the optical and digital setup, not a guarantee that any ceiling point is suitable.

The brightness and light-source story is shared with TK705i

The short-throw TK705STi uses BenQ 4LED technology and has a manufacturer rating of 3,000 ANSI lumens. That is not a verified measurement of your preferred movie mode, and the same headline brightness as TK705i doesn't mean every screen setup looks identical.

BenQ also quotes 98% Rec.709 coverage and a dynamic full-on/full-off contrast figure. The first describes an advertised color range; the second is not an independent native black-level result. Neither proves this lens produces better dark scenes than the standard model.

For family movie night, window shades and the right image size matter. A huge picture in a room with the lights on may look less satisfying than a smaller image with good light control.

BenQ estimates light-source life at 20,000 hours Normal and 30,000 hours Eco. Those are manufacturer operating-mode ratings, not guarantees that the entire projector lasts that long without servicing.

The 5ms gaming claim is mode-specific manufacturer information

BenQ quotes 5ms at 4K60, 5ms at 1080p60, and 5ms with 2K60 input downscaled to 1080p60. Those figures belong to the particular signal and settings stated by BenQ; they aren't independent PIQSY tests.

The model's published 23–60Hz scan rate also matters. HDMI 2.1 ports do not make it a native 4K120 projector simply because the connector is modern.

If you're playing story games and couch co-op at 4K60, the big picture and shorter lens distance may be more valuable than chasing a gaming headline. If competitive 120Hz or 240Hz play is essential, check a gaming-specific model with those documented modes. Don't compare its 4K60 rating directly with a rival's fastest 1080p240 reading.

Google TV makes it more than a projector-only box

The TK705STi has built-in Google TV, wireless casting and two 8W speakers, according to BenQ's US specification. These features help a family get from the home screen to a show with fewer separate components.

The speakers will be convenient for quick setup, but a soundbar may still be preferable for a dedicated movie room. The projector supports HDMI eARC and standard audio outputs. If you already use an AV receiver, check its passthrough and sound formats rather than assuming the new projector will solve every compatibility issue.

The USB-C connection carries a supported video input signal and a specified Power Delivery output profile. It isn't an alternative way to run the TK705STi from a phone charger or battery bank. Keep the actual AC requirement in the installation plan.

App availability is region-dependent and can change with streaming licensing. Verify any service that is central to your household before purchasing, even when Google TV appears on the feature list.

Short throw changes convenience, not permanent ownership costs

BenQ publishes cooling-noise figures for specific operating modes. A projector placed closer to the couch may be easier to hear, even when the rating looks modest. That is worth considering if the room is quiet and the screen is used mainly late at night.

Also plan for heat, dust exposure, firmware updates and any needed cleaning. A long-rated 4LED light engine doesn't mean every component lasts for the rated source hours. Your exact new, refurbished or bundled retail offer determines warranty and included equipment, not simply the manufacturer model name.

If you plan to move the projector frequently, remember that its fixed throw asks you to return it to a precise position every time. Automatic focus and keystone can reduce frustration, but they cannot make the lens behave like a zoom lens.

Owner feedback

There aren't enough dependable US owner reports about the exact TK705STi to judge recurring app issues or long-term reliability. Mixed retailer star scores won't answer those questions. Check support, warranty and the return window while you're measuring the room.

Who should choose something else

Choose the BenQ TK705i if your available projection distance supports a standard throw and its 1.3x optical zoom will simplify installation. The two should be judged on geometry before marketing claims about performance.

Choose the BenQ X500i if you specifically want a short-throw gaming-oriented model with documented 1080p120 and 1080p240 output modes. The X500i's lens, light-output rating and feature emphasis differ; don't substitute one gaming specification for the other.

Consider the Hisense PX3-PRO only if true UST placement near a suitable screen is the priority. That involves a different screen and cabinet budget. For completely mobile bedside viewing, a battery projector such as the BenQ GV50 is more natural.

Before you buy

Mark the intended image width and the lens position on your room plan. Check whether a fixed 0.8 ratio works without aggressive keystone or digital zoom, and reserve room for airflow and cables. Verify the exact US TK705STi, not TK705i, and the current seller's condition, bundle and warranty.

PIQSY conclusion

The TK705STi makes sense when a shallower living room needs a fixed 0.8 short-throw lens rather than the standard TK705i's optical zoom. Add Google TV, 4LED and maker-described 4K60 gaming, and it can be a practical all-around entertainment projector.

The trade-off is placement precision: the shorter lens can't optically zoom its way out of a poorly positioned shelf. Buy it because the distance works. If your existing mount is farther back, consider TK705i or another optical class instead.

Before purchasing: Check the precise US TK705STi bundle, seller warranty and current price. Performance and long-term owner results haven't been independently established for this listing.