BenQ W4100i Smart Projector

Brightness and picture modes

ProjectorCentral measured 3,240 ANSI lumens in Bright Normal, 2,106 in Bright Cinema, 2,009 in Cinema, 1,119 in Filmmaker SDR, 2,009 in HDR10 and 1,166 in Filmmaker HDR. The Bright preset is green-biased, so read that number as what the light source can do rather than what you should watch in. A separate test unit supplied by BenQ measured roughly 1,046:1 on/off contrast in Cinema Normal and about 1,704 lumens, which puts native contrast far below the figure printed on the box. Size your screen against the mode you will live with: Filmmaker SDR at 1,119 lumens across 100 inches wants a dark room and a high-gain surface.

Installation and placement

The throw ratio is 1.15–1.50:1, so a 100-inch 16:9 screen (about 87.2 inches wide) needs roughly 8.4–10.9 feet between lens and screen, and a 120-inch screen needs about 10.0–13.1 feet. Vertical lens shift covers 0–60% of the image, while horizontal shift reaches only ±15% and only at a 20.9% vertical position, so the two extremes cannot simply be combined. Digital keystone works out to ±30 degrees in each direction, but it costs sharpness and can disable Fast gaming mode. Measure the room and work from the official throw chart before drilling for a ceiling mount. The manual also asks for around 50cm of clearance at the inlets and outlets, and the 13.45lb chassis needs an anchored mount with room for heat.

Gaming and inputs

BenQ rates input lag at 17.9ms for 4K/60 and 1080p/60, 13ms for 1080p/120 and 6.5ms for 1080p/240; ProjectorCentral measured roughly 19ms, 15ms and 7ms in the same three modes. The catch sits on HDMI3: it takes a 4K/120 signal and then renders the picture at 1080p/120, so a 4K/120 console is not the experience the port label suggests. HDMI1 and HDMI2 carry 4K/60 with ALLM, and HDMI2 adds eARC for a soundbar or receiver. Fast mode is available, but it drops keystone correction and some processing.

Owner reports and image quirks

Single-chip DLP can throw red, green and blue flashes onto bright highlights and small text, and ProjectorCentral and What Hi-Fi? both caught them on this model. Presets will not remove them, so if you are sensitive to rainbows, look at real content in person first. Owners in r/projectors describe the same picture on their own units. One detailed owner reported rainbows, disappointing letterbox blacks, light spilling onto the wall next to the screen and a sluggish built-in streamer, and still kept the projector. Another posted a photo of light spill beyond the image on a 150-inch screen while showing a 120-inch image, with lens shift appearing to move the spill. A third thread covers clicking during picture-mode changes, which some owners read as an iris or mode-switching sound rather than a fault. Two owners compared the W4100i with the XGIMI Horizon 20 Pro and the Valerion VisionMaster Pro 2: one preferred the BenQ color but found the Valerion’s blacks deeper, another preferred BenQ color and sharpness and less rainbow than the XGIMI while finding it louder and slower. The Dynamic source modes can also shift color on some 4K scenes; Normal avoided that in ProjectorCentral’s testing, and a lower Dynamic setting weakens HDR punch. These are individual reports, not failure rates.

Store snapshots from October 2026 put the W4100i at $2,499 on BenQ’s own shop, a $500 cut from the $2,999 launch price, at $2,379 on promotion at B&H and at $2,799.99 at Best Buy. The captures disagree with each other, so check the cart at the store you plan to use. Electricity is the running cost: BenQ lists 330W typical at 110V and under 0.5W in standby, and three hours a day for 365 days works out to 1,095 hours and 361.35kWh, about $72.27 a year at an assumed $0.20 per kWh, with standby adding at most 3.83kWh (roughly $0.77). There is no lamp to buy and no paid streaming tier; the LED block is rated 20,000 hours in Normal and 30,000 in ECO, and the manual says it is not user-serviceable. BenQ listed a replacement RCI074 remote, a QS02 dongle at $149 and a CMG3 ceiling mount at $79 in October 2026, so confirm the mount’s thread pattern and weight rating before ordering. The US warranty covers eligible new units for three years parts and labor, one year on refurbished units, with a free shipping label to an authorized service center for covered claims, though the owner supplies the packaging. Coverage can be affected by dust, temperatures outside 0–35°C, humidity outside 10–90% and elevations above about 4,920 feet.

Sources

Manufacturer:

• BenQ W4100i user manual (PDF)
• BenQ W4100i official specifications
• BenQ US projector store
• BenQ US projector warranty terms
• BenQ US shopping FAQ
• BenQ QS02 Android TV dongle specifications
• BenQ W4100i launch release

Independent reviews:

• What Hi-Fi?: tested W4100i with rainbow, black level and noise reduction findings
• r/BenQ: color, contrast and brightness measurements on a BenQ-supplied sample

Store listings:

• Best Buy: W4100i listing

Owner reports:

• r/projectors: an owner on rainbows, blacks, light spill and the streamer
• r/projectors: light spill beyond the screen
• r/projectors: clicking during image mode changes