Optoma · 3,000–4,999 lumens · 4K
Optoma ZK420UST
4,200lumens
3840×2160native
0.25–0.25throw ratio
4.5 kgweight
The Optoma ZK420UST is a DLP x 1 projector rated at 4,200 lumens with a native resolution of 3840×2160. It uses a laser phosphor light source rated for 30,000 hours. Its lens has a throw ratio of 0.25:1. Released May 2025.
Throw distance table
Distance from lens to surface for each image width (16:9 (4K HD)). Calculated as throw ratio × width; check the manufacturer's lens calculator before installation.
| Image width | Height | Standard lens 0.25:1 |
|---|---|---|
| 2 m (6.6 ft) | 1.12 m | 0.5 m |
| 3 m (9.8 ft) | 1.69 m | 0.8 m |
| 4 m (13.1 ft) | 2.25 m | 1.0 m |
| 5 m (16.4 ft) | 2.81 m | 1.2 m |
| 6 m (19.7 ft) | 3.38 m | 1.5 m |
| 8 m (26.2 ft) | 4.5 m | 2.0 m |
| 10 m (32.8 ft) | 5.62 m | 2.5 m |
| 12 m (39.4 ft) | 6.75 m | 3.0 m |
| 15 m (49.2 ft) | 8.44 m | 3.8 m |
| 20 m (65.6 ft) | 11.25 m | 5.0 m |
| 25 m (82.0 ft) | 14.06 m | 6.2 m |
| 30 m (98.4 ft) | 16.88 m | 7.5 m |
Open in the throw-distance calculator →
Maximum image size for projection mapping
Largest image that keeps a 10:1 contrast against ambient light on a light, matte surface (80% optical efficiency). See how this is calculated.
| Ambient light | Max area | Max width × height |
|---|---|---|
| Dark rural site (1 lux) | 373 m² | 25.8 × 14.5 m |
| Quiet street at night (5 lux) | 75 m² | 11.5 × 6.5 m |
| Lit city square (15 lux) | 25 m² | 6.7 × 3.7 m |
| Bright urban area (30 lux) | 12 m² | 4.7 × 2.6 m |
| Indoor, lights dimmed (50 lux) | 7 m² | 3.6 × 2.0 m |
Full specifications
| 3D Modes | Full HD 3D |
|---|---|
| Aspect Ratio | 16:9 (4K HD) |
| Audible Noise | 34 dB / 29 dB (Eco) |
| Best Used For | K-12 Education Corporate/Business |
| Brightness | 4,200 Lumens (ISO) 2 |
| Color Processing | 10-bit |
| Connection Panel | Audio Out: Mini Jack HDBaseT: RJ-45 HDMI 2.0 x 2 Network: RJ-45 RS232: DB-9pin USB: A |
| Contrast | 1,800:1 (full on/off) |
| Data Modes | MAX 3840x2160 |
| Digital Keystone | Horizontal & Vertical |
| Digital Zoom | Yes |
| Display Type | DLP x 1 |
| Dynamic Contrast | 500,000:1 |
| Features | Short-Throw 24/7 Operation Full HD 3D Geometric Correction HDR HDMI CEC Blackboard Mode Crestron RoomView™ |
| Image Size | 99.68" - 150.35" |
| Included Lens | Fixed focal length , manual focus |
| Input Lag | 4K/60: 16.9ms | 1080p/60: 17ms | 1080p/120: 8.6ms |
| Internal Speakers | 15.0 Watts Mono |
| Lens Shift | No |
| Light Source | Laser Phosphor |
| Light Source Life | 30,000 hours |
| MSRP | n/a |
| Power | 255 Watts 100V - 240V |
| Projector Size | 3.35" x 12.87" x 12.91" (HxWxD) |
| Released | May 2025 |
| Resolution | 3840x2160 |
| Status | Shipping |
| Street Price | $3,839 (USD) |
| Throw Distance | 1.8' - 2.7' Calculate Throw Distance |
| Throw Ratio | 0.25:1 (D:W) |
| Video Modes | 720p, 1080i, 1080p/60, 1080p/50, 2160p/60, 576i, 576p, 480p, 480i |
| Warranty | 3 Years |
| Weight | 9.9 lbs |
Specifications compiled from ProjectorCentral and manufacturer data. Prices change — verify with dealers.
Similar projectors
| Model | Lumens | Resolution | Light source | Throw ratio | Street price |
|---|---|---|---|---|---|
| Optoma ZK450 | 4,200 | 3840×2160 | Laser Phosphor | 1.4–2.24:1 | $1,999 |
| Optoma ZK431ST | 4,100 | 3840×2160 | Laser Phosphor | 0.5:1 | |
| Optoma ZK431ST-B | 4,100 | 3840×2160 | Laser Phosphor | 0.5:1 | $1,799 |
| Optoma GT3900UHD | 4,000 | 3840×2160 | Laser Phosphor | 0.5:1 | $1,499 |
| Optoma UHZ66 | 4,000 | 3840×2160 | Laser Phosphor | 1.4–2.24:1 | $1,895 |
| Optoma 4K400STx | 4,000 | 3840×2160 | 240W Metal Halide bulb | 0.5:1 | $1,999 |
| Optoma 4K400x | 4,000 | 3840×2160 | 240W Metal Halide bulb | 1.5–1.66:1 | $1,424 |
| Optoma GT4000UHD | 4,000 | 3840×2160 | Laser Phosphor | 0.25:1 | $3,499 |