Our take
Consider the BenQ TK850i when a home theater needs 4K UHD output and an included Android TV source. BenQ's specification distinguishes it from the similarly named TK850 and gives a 3,000 ANSI-lumen rating plus vertical lens shift.
Home viewing when 4K UHD output and a supplied Android TV source are both useful.
It is not for buyers who require a documented native 3840-pixel panel, battery use, or a guarantee that a particular streaming service remains supported.
Pros & cons
What could work for you, and what to consider before buying.
What works in its favor
- BenQ specifies 4K UHD 3840 × 2160 output and a 3,000 ANSI-lumen rating.
- The standard QS01 Android TV dongle and Google Cast reduce the need for a separate streaming box.
- A 1.3× zoom and +10% vertical lens shift allow installation adjustment.
What to weigh up
- The saved specification does not establish a native 3840-pixel imaging panel.
- Streaming service support and software behavior can change; check the current unit and region.
- The lamp requires condition and hours checks on a used projector.
The key details
| Model covered | TK850i |
|---|---|
| Image format | 4K UHD 3840 × 2160 output |
| Rated light output | 3,000 ANSI lumens |
| Placement | 1.13–1.47:1 throw, 1.3× zoom, +10% vertical shift |
Performance figures are manufacturer claims. Source checked October 8, 2026. Regional models and included accessories can differ.
What the features mean for you
Treat 4K output precisely
BenQ specifies a 3840 × 2160 4K UHD image for the TK850i. The saved product page establishes that output format but does not establish that the imaging device has 3840 native horizontal pixels. That distinction helps avoid transferring a native-panel claim from the output label. For a home cinema, the 4K UHD format may be central to the desired source chain; compare it with other output-based models using the same careful language, and check the source device's supported signal format before installing the projector.
The light rating helps frame the room
The TK850i is specified at 3,000 ANSI lumens. That is a higher stated ANSI figure than the UHD51A's 2,400, but room light, image size, screen surface, and lamp condition still affect the picture. The rating helps frame a comparison; it does not make every large screen suitable for daylight use. Check the intended image dimensions and how much room light can be controlled. Keep the number tied to the official model specification and avoid treating it as a measured result from an individual unit.
A supplied source changes setup
BenQ lists Android 10 and a standard QS01 Android TV dongle, along with Google Cast and three HDMI inputs. This can simplify a home setup that otherwise needs a streaming stick, but it is not a permanent promise about app availability or subscriptions. Confirm current service support on the exact device and region. HDMI remains useful for a console, receiver, or separate player, and the dongle's inclusion should be checked on a used offer rather than assumed from the model name alone.
Use the lens range in a measured installation
The official specification gives a 1.13–1.47:1 throw ratio, 1.3× zoom, and +10% vertical lens shift. These controls can make it easier to adapt a ceiling mount or shelf to the screen, while still requiring a measured distance and height. The lens is conventional rather than ultra-short-throw, so it needs room behind the screen. Vertical shift can adjust optical placement; it does not replace checking the projection chart or make horizontal alignment unlimited.
Check the exact variant and lamp
The final letter matters: the TK850i is not the same catalog identity as the released TK850. BenQ's page documents the i model's standard dongle and its own specification set, so do not transfer facts across suffixes without evidence. As a lamp projector, an older unit's hours and condition also matter. Confirm the model label, remote, power lead, dongle, firmware behavior, and working connections for the actual offer. This is a feature-based assessment, not a claim that a used unit is in a particular condition.
What else to compare
Compare Optoma UHD51A for 4K UHD output with a different lens and source arrangement, or BenQ HT3050 for Full HD and a documented vertical shift.
Before you buy
Is the TK850i native 4K?
BenQ specifies 4K UHD output, but the saved page does not establish a native 3840-pixel imaging panel.
Does the TK850i include Android TV?
BenQ lists a standard QS01 Android TV dongle with Android 10; verify that the dongle is present on a used unit.
Will every streaming app work?
The documented platform does not guarantee current service availability, certification, or subscription access for every region.
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 TK850i specifications ↗ — checked October 8, 2026.
- BenQ TK850i specifications ↗ — checked October 8, 2026.
The decision
The TK850i suits a planned home setup that values 4K UHD output, a supplied Android TV dongle, and lens adjustment, with current app support verified separately.
Is it the right fit?
Check the exact model and today’s offers on Amazon.