Optoma ZH451ST vs Optoma ZK420UST
 $1,499 | | |
|---|---|---|
| Key differences | ||
| White light output | 4,200 lm ISO | 4,200 lm ANSI |
| Native resolution | 1080p (1920 × 1080) | — |
| Throw ratio | 0.5:1 | 0.25:1 |
| Lowest input lag | 8.4 msDerived | 4.3 msDerived |
| Fan noise | Normal 36 dB(A) · Eco 29 dB(A) | Max 34 dB(A) · Eco 29 dB(A) |
| Price | $1,499 | — |
| Room fit | ||
| Distance to screen | 1.1 m | 0.55 m |
| Brightness | ||
| Rated brightness | 4,200 lmDerived | 4,200 lmDerived |
| White light output | 4,200 lm ISO | 4,200 lm ANSI |
| Brightness uniformity | 75% | 75% |
| Display system | ||
| Imaging technology | DLP | DLP |
| On-screen resolution | 1080p (1920 × 1080)Derived | 4K UHD (3840 × 2160)Derived |
| Native resolution | 1080p (1920 × 1080) | — |
| Native aspect | 16:9Derived | 16:9Derived |
| Pixel shift | — | XPR 4-way |
| Addressable resolution | — | 4K UHD (3840 × 2160) |
| Contrast | ||
| Dynamic contrast | 2,000,000:1 | 500,000:1 |
| Colour | ||
| Colour bit depth (per channel) | 10 bit | — |
| Gamma / EOTF presets | 2.2, 2.4 | 2.2, 2.4 |
| HDR | ||
| HDR formats | HDR10, HLG | HDR10, HLG |
| Calibration | ||
| Colour management (CMS) | 6-axis | — |
| Picture certifications | ISF, Filmmaker Mode | — |
| 3D | ||
| 3D | Yes | Yes |
| 3D formats | Side-by-side, Top-bottom, Frame sequential | + Frame packing, Side-by-side, Top-bottom, Frame sequential |
| 3D glasses sync | DLP-Link | DLP-Link |
| Light source | ||
| Light source | Laser (phosphor) | Laser (phosphor) |
| Emitter | Blue laser + phosphor | — |
| Light engine | DuraCore | — |
| Light-source life | 30,000 h | 30,000 h eco |
| Light output control | Steps | Steps |
| Constant brightness mode | Yes | — |
| Cool-down time | 90 s | — |
| Optics | ||
| Throw ratio | 0.5:1 | 0.25:1 |
| Image size | 30–300 in | 100–150 in |
| Projection offset | 116% | 120% |
| Zoom | Digital | None |
| Focal length | 7.51 mm | 3.7 mm |
| Aperture (f-number) | 2.8 | 2.44 |
| Focus | Manual | Manual |
| Autofocus | No | — |
| Vertical keystone | 15° | — |
| Horizontal keystone | 15° | — |
| Corner correction | 4-corner | 4-corner |
| Grid warp | — | Yes |
| Interchangeable lens | — | No |
| Motion & gaming | ||
| Input lag | About 1080p: 60 Hz 16.7 ms · 120 Hz 8.4 ms · 4K UHD: 60 Hz 16.7 ms | 1080p: 60 Hz 17 ms · 120 Hz 8.6 ms · 240 Hz 4.3 ms · 4K UHD: 60 Hz 16.9 ms |
| Lowest input lag | 8.4 msDerived | 4.3 msDerived |
| Input lag at 4K 60 Hz | 16.7 msDerived | 16.9 msDerived |
| Inputs & control | ||
| HDMI inputs | 2 × HDMI 2.0 | 2 × HDMI 2.0 |
| HDMI inputs (count) | 2Derived | 2Derived |
| Newest HDMI version | HDMI 2.0Derived | HDMI 2.0Derived |
| Other video inputs | + VGA | + HDBaseT |
| Max input resolution | 4K UHD | 4K UHD |
| Control ports | RS-232, + Wired IR, + 12 V trigger | RS-232 |
| PJLink | Class 1 | — |
| Control-system drivers | Crestron | — |
| Horizontal scan | 15–135 kHz | 15–150 kHz |
| Vertical scan | 24–120 Hz | 24–240 Hz |
| Smart platform | ||
| Ethernet | Yes | Yes |
| Audio | ||
| Speaker power | 15 W | 15 W |
| Speakers | 1 | 1 |
| Layout | Mono | Mono |
| Audio outputs | — | 3.5 mm, HDMI eARC |
| HDMI audio return | — | eARCDerived |
| Physical & installation | ||
| Dimensions (W × D × H) | 274 × 216 × 114 mm | 327 × 328 × 110 mm |
| Weight | 3,000 g | 4,200 g |
| Orientations | Portrait, 360° | Portrait, 360° |
| Ceiling mount | M4, 10 mm screws | M4, 10 mm screws |
| Ingress protection | IP6X | IP6X |
| Environment & power | ||
| Operating temperature | 0–40°C | 0–40°C |
| Operating humidity | — | 10–85%RH |
| Altitude | 2,500 m · high-altitude mode | 3,048 m · high-altitude mode |
| Power draw | Max 170 W | Max 255 W · Eco 180 W |
| Standby | Up to 0.5 W | 0.5 W |
| Power supply | External adapter | External adapter |
| Mains input | 100–240 V · 50/60 Hz | 100–240 V · 50/60 Hz |
| DC input | — | 24 V |
| Noise | ||
| Fan noise | Normal 36 dB(A) · Eco 29 dB(A) | Max 34 dB(A) · Eco 29 dB(A) |
| Safety & compliance | ||
| Laser class | Class 1 | Class 1 |
| Risk group | RG2 | RG2 |
| Hazard distance | 1 m | — |
| FDA laser notice | — | Notice 57 |
| Marks | FCC | FCC |
| Support & ownership | ||
| Warranty | — | 3 yr (light source 5 yr or 12,000 h) |
| User manual | https://region-resource.optoma.com/products/documents/0NL94Q0vvVEJVe7dxQKlMzhtuURlT8FwUXNkLi8y.pdf | — |
| In the box | ||
| In the box | Power cord, Remote, Remote batteries, Quick start guide | Power cord, + Power adapter, Remote, Remote batteries, Quick start guide |
| Remote | IR | IR |