Optoma ZK431ST 4K UHD Short Throw Laser Projector
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Optoma ZK431ST – 4K UHD Short Throw DuraCore Laser Projector

The Optoma ZK431ST is one of Optoma's most compact and hassle-free 4K UHD DuraCore laser projectors. Designed for maintenance-free continuous operation, this 4,100-lumen short throw projector delivers powerful image performance with flexible installation features and extensive connectivity in a sleek form factor — up to 34% smaller than previous Optoma models.
Supporting Optoma's commitment to sustainability, the ZK431ST cuts power consumption by up to 45% compared to lamp-based projectors. Energy-saving DuraCore laser technology ensures a long product lifespan of up to 30,000 hours without additional lamps, requires minimal maintenance, and is mercury-free.
Geared for conference rooms, boardrooms, and corporate spaces, the ZK431ST's short throw lens can be positioned less than half a metre from any wall. Remote management is available via Optoma Management Suite (OMSC)™ and the Optoma Smart Control App for Android and iOS.

Technical Specifications
| Specification | Detail |
|---|---|
| Display Technology | DLP® |
| Resolution | 4K UHD (3840 x 2160) |
| Brightness | 4,100 lumens |
| Contrast Ratio | 300,000:1 |
| Native Aspect Ratio | 16:9 |
| Compatible Aspect Ratios | 4:3, 16:9, 16:10, 21:9, 32:9 |
| Displayable Colours | 1,073.4 million |
| Screen Size | 0.91 m – 7.62 m (36" – 300") diagonal |
| Horizontal Scan Rate | 15 – 150 kHz |
| Vertical Scan Rate | 24 – 240 Hz |
| Uniformity | 75% |
| Keystone Correction (H/V) | ±15° / ±15° |
| Light Source | Laser (DuraCore) |
| Laser Lifespan | 30,000 hours |
| Throw Ratio | 0.496:1 |
| Projection Distance | 0.4 m – 3.3 m |
| Zoom Type | Fixed |
| Focal Length | 7.51 mm |
| Native Offset | 114% |
| Inputs | 1 x HDMI 2.0, 1 x HDMI 2.0 (eARC) |
| Outputs | 1 x Audio 3.5 mm, 2 x USB-A power 1.5A |
| Control Ports | 1 x RS232, 1 x RJ45, 1 x 12V trigger, 1 x 3D sync |
| Speaker | 1 x 15W built-in |
| 3D Support | Full 3D (DLP 3D; PC frame sequential 120Hz, Blu-ray DVD 3D) |
| IP Rating | IP6X (dust-proof) |
| Noise Level | 29 dB (min) / 35 dB (max) |
| 24/7 Operation | Yes |
| 360° Operation | Yes |
| Operating Conditions | 0°C – 40°C, Max. Humidity 80%, Max. Altitude 2,500 ft |
| Security | Security bar, Kensington Lock, Password protected interface |
| OSD Languages | 25 languages |
| Power Supply | 100V – 240V, 50–60 Hz |
| Power Consumption (Standby) | <0.5W |
| Power Consumption (Min/Max) | 124W / 178W |
| Dimensions (W × D × H) | 274 × 216 × 114 mm |
| Net Weight | 2.9 kg |
| Gross Weight | 4.3 kg |
| Country of Origin | China |
What's in the Box
- Optoma ZK431ST projector
- AC power cord
- Remote control
- 2 x AAA batteries
- Basic user manual
Why Choose the Optoma ZK431ST?
The ZK431ST combines true 4K UHD resolution with a ultra-short throw ratio of 0.496:1, making it ideal for space-constrained boardrooms and conference rooms. DuraCore laser technology eliminates lamp replacements, delivers consistent brightness over 30,000 hours, and reduces total cost of ownership. With IP6X dust protection, 24/7 operation capability, and full remote management via OMSC™, the ZK431ST is engineered for demanding professional environments.
Caring for your Speakers and Amplifiers
To Keep your equipment safe these are some best practices to note. Please be advised that this is only to reduce the risk of misuse and is not an exhaustive list.
Speakers
- Speaker terminals are marked red and black, ensure your amplifier to the speakers are wired on the same colours
- Ensure no loose speaker wire from the red touches a loose wire from the black as this will lead to a short circuit and damage either the speaker, the amplifier or both.
- Not all speakers are designed to play at max volume, kindly consider the pairing of your amplifier and speakers
- Speaker cabinets cannot be replaced please handle with care.
AV & Stereo Amplifiers
- If your amplifier has HDMI ports, ensure all devices are off before plugging in the HDMI cable
- Turn off the amplifier before swoping out or adding speaker cable
- Amplifiers generate heat, place them in a well ventilated space. if possible avoid having anything on top of the unit.
- adding a surge protector can assist with power dips which are likely to damage your devices. Isotek and Furman are industry standard.
- Dusty environments can sometimes lead to accumulation of dust in the electronic components that might affect heat regulation
Shipping & Returns
- Free shipping on orders over R500 within the country.
- Standard delivery within 2–5 business days. Delays will be communicated. This might vary slightly depending on your location.
- Return items in original condition for a full refund. (unopened state)
- Returns that are open/unboxed will be subject to a handling fee. Refunds will only be processed after testing the unit.
