Optoma ZK521ST-B 4K UHD Short-Throw Laser DLP Projector - Black

Classrooms and meeting rooms get a sharp 4K UHD image from a short distance with the Optoma ZK521ST, a compact 5,000-lumen laser DLP projector.

Its 0.79:1 lens fills a 100-inch screen from about 5.5 feet, and Robertson AV can quote multi-room orders.

Key Features

• Brightness: 5,000 lumens
• Resolution: 4K UHD (3840 x 2160)
• Laser light source: 30,000 hours
• Throw ratio: 0.79:1, Fixed short-throw lens lens
• Operation: 24/7
• Connections: 2 x HDMI 2.0, VGA in, 3.5 mm audio, 2 USB-A 2.0, 3D sync out, RJ-45, RS-232, 12V trigger
• Built-in sound: Mono speaker
• Network control: LAN, RS-232 and 12V trigger

Ideal For

• Classrooms: low-maintenance laser
• Meeting rooms: tight installs
• Training rooms: easy setup

Optoma ZK521ST-B 5,000-Lumen 4K UHD Short-Throw Laser DLP Projector (Black) Specifications

Optoma ZK521ST technical specifications, grouped by feature

Specification	Details
Picture & Optics
Resolution	4K UHD (3840 x 2160)
Brightness	5,000 lumens
Contrast Ratio	300,000:1 (2,000,000:1 dynamic)
Throw Ratio	0.79:1
Lens	Fixed short-throw lens
Projection Distance	0.89 – 2.93 m (optical travel)
Keystone Correction	Horizontal and vertical +/-15 degrees
Light Source
Light Source	Laser, 30,000 hours
Power & Environment
Noise Level	29 dB(A)
Power Consumption	147 W eco; 196 W bright; 0.5 W or less standby
Physical
Dimensions (W x D x H)	216 x 274 x 108.5 mm (10.8 x 8.5 x 4.3 in)
Net Weight	3.0 kg (6.6 lb)
Additional Features
Display Technology	DLP
Focal Length	11.6 mm
Screen Size	30 – 300 in
Native Offset	Vertical 104% – 125%
Connections	2 x HDMI 2.0, VGA in, 3.5 mm audio, 2 USB-A 2.0, 3D sync out, RJ-45, RS-232, 12V trigger
Operating Conditions	0 to 40°C, up to 80% humidity
General
Brand	Optoma
Model	ZK521ST
Manufacturer Part Number	ZK521ST-B

Specifications are verified against the Optoma manufacturer data sheet (October 2026) and may change without notice. Confirm critical requirements with Optoma before ordering.

What’s in the Box

• AC power cord
• Remote control
• Batteries
• Quick start guide

Warranty & Support

Planning a multi-room or multi-site install? Request a quote from Robertson AV for 5 or more units, or call us at 800-919-6548 or email orders@robertsonav.com. Free ground shipping on U.S. orders. Schools, businesses, government agencies and houses of worship: ask us about project and quantity pricing.

Optoma documents the ZK521ST; this listing is the black model ZK521ST-B.