Optoma ZK551: Specs, Throw Distance & Alternatives
A 4K laser phosphor DLP projector rated by Optoma at 5,100 ISO lumens. Optoma publishes lag claims of 17 ms at 4K/60 and 4.4 ms at 1080p/240. It has a 1.6x zoom and a small vertical lens shift, but no smart TV system; casting uses Miracast, AirPlay or Chromecast.
Is the Optoma ZK551 right for you?
Good for
- Bright rooms: 5,100 ISO lumens rated
- Console gaming at 4K/60 or 1080p/60 (Optoma claims 17 ms)
- High-refresh PC gaming at 1080p/240 (Optoma claims 4.4 ms)
- Placement flexibility: a 1.6x manual zoom plus vertical lens shift
What to plan for
- No smart TV system: casting uses Miracast, AirPlay or Chromecast, and Wi-Fi needs a USB dongle (Optoma does not confirm one is included)
- 4K comes from DLP pixel shift, and 4K input is HDMI 2.0
- Lens shift is vertical only, +15%
- Manual focus, a single 15 W mono speaker and 3.5 mm audio out, with no ARC listed
- Light source life is published for Eco mode only (30,000 hours)
Based on manufacturer specifications and published reviews (sources below). We don't do hands-on testing.
Optoma ZK551 specs
| Resolution | 4K UHD (3840 × 2160, DLP pixel shift) |
|---|---|
| Brightness | 5,100 ISO lumens (Optoma rating, ISO 21118) |
| Display technology | DLP |
| Light source | Laser phosphor (DuraCore) |
| Light source life | 30,000 hours (Eco mode, Optoma rating) |
| Contrast ratio | Not confirmed (Optoma lists both 3,000,000:1 and 300,000:1) |
| Throw ratio | 1.4-2.24:1 |
| Lens shift | Vertical +15% (101.5% to 116.6% offset); no horizontal shift |
| Max refresh rate | 240 Hz |
| HDMI ports | 2 (HDMI 2.0) |
| Speakers | 15 W |
| Weight | 7.7 lb |
How far from the screen?
Lens-to-screen distance for a 16:9 image, calculated from its 1.4-2.24:1 throw ratio. The zoom lets you place it anywhere in the range.
| Screen | Closest | Farthest |
|---|---|---|
| 80″ | 8' 2" | 13' 0" |
| 100″ | 10' 2" | 16' 3" |
| 120″ | 12' 2" | 19' 6" |
| 150″ | 15' 3" | 24' 5" |
Optoma ZK551 input lag by mode
| Signal | Input lag |
|---|---|
| 1080p / 240 Hz | 4.4 ms |
| 1080p / 120 Hz | 8.6 ms |
| 1080p / 60 Hz | 17 ms |
| 4K / 60 Hz | 17 ms |
Source: Optoma’s published claims; no independent measurement is listed. Its fastest figure (4.4 ms at 1080p / 240 Hz) is quicker than 76 of the 96 projectors with a lag figure in our input lag database, which lists each model's fastest mode.
Optoma ZK551 alternatives at a similar price
In-stock 4K projectors priced closest to it on Amazon today.
| Model | Price today | Amazon rating | Compare |
|---|---|---|---|
| Optoma ZK551 (this one) | $2,089 | — | — |
| XGIMI HORIZON 20 Pro 4K RGB Triple Laser Home Projector | $1,999 | 4.3★ | — |
| BenQ TK710STi 4K HDR Laser 3200 Lumens Movie and Gaming Shor | $1,999 | 4.3★ | — |
| JMGO N3 Ultimate 4K Triple Laser Projector | $2,199 | — | — |
| JMGO O2S Ultra UHD 4K Ultra Short Throw Projector | $2,199 | — | — |
Where it fits
Optoma ZK551 FAQ
- How far from the screen should the Optoma ZK551 be for a 100-inch image?
- Between 10' 2" and 16' 3" from lens to screen, depending on the zoom setting (throw ratio 1.4-2.24:1).
- What is the input lag of the Optoma ZK551?
- 1080p / 240 Hz: 4.4 ms; 1080p / 120 Hz: 8.6 ms; 1080p / 60 Hz: 17 ms; 4K / 60 Hz: 17 ms. Source: Optoma’s published claims; no independent measurement is listed.
- Is the Optoma ZK551 native 4K?
- No. Its resolution is 4K UHD (3840 × 2160, DLP pixel shift). It builds the 4K image with pixel shifting instead of a native 3840 × 2160 chip or panel.
- Does the Optoma ZK551 have lens shift?
- Yes, but only vertically: +15%, taking the offset from 101.5% to 116.6%. It has no horizontal lens shift.
Sources
Price, stock and rating come from Amazon and update automatically (last checked Nov 14, 2026, 10:00 PM).
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