Optoma GT3900UHD vs ViewSonic PX749-4K
Bold marks the better figure where both are stated to the same standard. “—” means the manufacturer doesn't state it.
 Optoma GT3900UHDMSRP $1,899 |  ViewSonic PX749-4KMSRP $1,199.99 | |
|---|---|---|
| Display system | ||
| Imaging technology | DLP | DLP |
| Technology brand | DLP | DLP |
| Number of imaging devices | 1 | 1 |
| Chip / panel diagonal | — | 0.47 in |
| Native aspect ratio | 16:9 | 16:9 |
| Addressable resolution | 3840 × 2160 | 3840 × 2160 |
| Optics | ||
| Throw ratio | 0.5:1 | 1.13–1.47:1 |
| Projection distance table | 30″: 0.33 m · 40″: 0.44 m · 50″: 0.55 m · 60″: 0.66 m · 70″: 0.77–0.77 m · 80″: 0.88 m · 90″: 0.99 m · 100″: 1.1–1.1 m · 120″: 1.32 m · 150″: 1.65 m · 180″: 1.98 m · 200″: 2.2 m · 250″: 2.75 m · 300″: 3.3 m | 60″: 1.5–1.95 m · 70″: 1.75–2.27 m · 80″: 2–2.59 m · 90″: 2.25–2.92 m · 100″: 2.49–3.24 m · 110″: 2.74–3.57 m · 120″: 2.99–3.89 m · 130″: 3.24–4.22 m · 140″: 3.49–4.54 m · 150″: 3.74–4.86 m · 160″: 3.99–5.19 m · 170″: 4.24–5.51 m · 180″: 4.49–5.84 m · 190″: 4.74–6.16 m · 200″: 4.99–6.49 m |
| Zoom type | None | Optical |
| Zoom ratio | — | 1.3× |
| Focus | Manual | Manual |
| Vertical lens shift | 0% | 0% |
| Horizontal lens shift | 0% | 0% |
| Fixed offset | 114% | 10% |
| Focal length | 7.51 mm | 12–15.6 mm |
| F-number | 2.8 | 1.94–2.12 |
| Image size range | 30–150 in | 30–300 in |
| Vertical keystone | -15–15° | -40–40° |
| Horizontal keystone | -15–15° | -40–40° |
| Corner / warp correction | Warp | 4pt |
| Light source | ||
| Light source type | Laser (phosphor) | Lamp |
| Light source detail | Laser (Optoma DuraCore) | 240W UHP lamp (E20.7i); replacement RLC-127 |
| Lamp wattage | — | 240 W |
| Light source life | Eco: 30,000 h | Normal: 4,000 h · Super eco: 20,000 h |
| Constant brightness mode | Yes | — |
| Warm-up time | 10 s | — |
| Cool-down time | 10 s | — |
| Light-source dimming | Manual steps | Manual steps |
| Brightness | ||
| ISO light output | 4,000 lm | — |
| ANSI lumens | — | 4,000 lm |
| Brightness uniformity (centre-to-corner) | 75% | — |
| Contrast & black level | ||
| Dynamic contrast | 2,000,000:1 | 12,000:1 |
| Colour | ||
| Colour temperature presets | — | D65, Custom |
| Gamma / EOTF presets | 2.2, 2.4 | 2.2 |
| Bit depth / 'number of colours' | 30 bitDerived | 10 bit |
| Calibration & picture control | ||
| Colour management system | 6-axis | — |
| ISF certified | Yes | — |
| HDR | ||
| HDR formats | HDR10, HLG | HDR10, HLG |
| Tone mapping type | — | Adjustable |
| Motion & gaming | ||
| Max refresh rate | 1920×1080: 240 Hz · 3840×2160: 60 Hz | 1920×1080: 240 Hz · 3840×2160: 60 Hz |
| Input lag (rated) | 3840×2160 @ 60 Hz: 16.7 ms · 1920×1080 @ 60 Hz: 16.7 ms · 1920×1080 @ 120 Hz: 8.6 ms · 1920×1080 @ 240 Hz: 4.3 ms | 1920×1080 @ 240 Hz: 4.2 ms |
| Audio | ||
| Speaker power | 15 W | 10 W |
| Speaker count | 1 | — |
| Audio channels | Mono | Mono |
| Audio partner | — | Harman |
| Audio outputs | 3.5 mm, HDMI eARC | 3.5 mm |
| HDMI eARC | Yes | — |
| Inputs, control & connectivity | ||
| Max input signal | 3840 × 2160 | 3840 × 2160 |
| HDMI port count | 2 | 2 |
| HDMI ports (feature-level) | HDMI 2.0: HDMI 2.0; HDMI 2.0 (eARC): HDMI 2.0, eARC | HDMI 1: HDMI 2.0, HDCP 2.2; HDMI 2: HDMI 2.0, HDCP 2.2 |
| Horizontal scan frequency | 15–150 kHz | 15–135 kHz |
| Vertical scan frequency | 24–240 Hz | 23–240 Hz |
| USB-C video (DP Alt Mode) | — | Yes |
| RS-232 | Yes | Yes |
| LAN control | Yes | Yes |
| 12 V trigger | Yes | Yes |
| PJLink class | Class 1 | — |
| Control ecosystem drivers | Crestron | — |
| Ethernet | Yes | Yes |
| 3D | ||
| 3D support | Yes | Yes |
| 3D sync method | DLP-Link | — |
| 3D formats | Frame packing, Side-by-side, Top-bottom, Frame sequential | Frame sequential, Frame packing |
| Glasses included | 0 | — |
| Setup automation | ||
| Auto keystone | — | Yes |
| Acoustic noise | ||
| Fan noise (sound pressure) | Eco: 28 dB(A) · Bright: 35 dB(A) | Normal: 33 dB(A) · Eco: 28 dB(A) |
| Environment & power | ||
| Operating temperature | 0–40°C | 0–40°C |
| Operating humidity | 10–85%RH | 0–90%RH |
| Altitude / high-altitude mode | 2,500 m | 3,000 m |
| High-altitude mode | Yes | Yes |
| Operating orientations | Table, Ceiling, Rear, 360°, Portrait | Table, Ceiling, Rear |
| Rated voltage | 100–240 V | 100–240 V |
| Rated frequency | 50–60 Hz | 50–60 Hz |
| Power consumption (max) | 178 W | — |
| Power consumption by mode | Eco: 125 W · Bright: 178 W | Normal: 310 W |
| Standby power | 0.5 W | 0.5 W |
| Power supply | External brick | — |
| Physical & installation | ||
| Width | 274 mm | 312 mm |
| Depth | 216 mm | 222 mm |
| Height | 114 mm | 108 mm |
| Weight | 2.9 kg | 3 kg |
| Ingress protection | IP6X | — |
| Colours / finishes | Black | — |
| Mount hole pattern | — | Thread: M4 · Max screw length mm: 8 |
| Safety & compliance | ||
| Photobiological risk group | RG2 | RG2 |
| Hazard distance | 1 m | — |
| Laser product class | Class 1 | — |
| Safety & market certifications | FCC, CE | CE, FCC |
| Support & ownership | ||
| Warranty | 🇺🇸 US 5 yr or 12,000 h | 🇺🇸 US 3 yr |
| Light-source warranty | — | 1 year on the original lamp (North and South America; 90 days under heavy use of more than 14 hours daily) |
| User manual | https://region-resource.optoma.com/products/documents/CWqYJUpb2tPRrTwMj1QGYRcPXH2q7xeKXHsKXAZ4.pdf | https://www.viewsonicglobal.com/public/products_download/user_guide/projector/PX749-4K/PX749-4K_UG_ENG.pdf |
| In the box | ||
| Box contents | Projector, Remote, Batteries, Power cord, Power adapter, Quick start guide, Warranty card | Projector, Power cord, Remote, Quick start guide |
| Remote type | IR | Backlit |
| 3D glasses in box | 0 | — |