ACTi Q550 vs Vivotek IT939-HTVW-1Y: Specification Comparison
Both the ACTi Q550 and the Vivotek IT939-HTVW-1Y are 8MP outdoor turret cameras targeting perimeter and building-edge surveillance. The Q550 is a dual-sensor 180° multi-imager design, while the IT939-HTVW-1Y is a single-sensor 4K unit with a motorized varifocal lens. Despite sharing the same resolution class and turret form factor, they serve meaningfully different deployment profiles—wide-area coverage versus flexible single-scene zoom—making them a legitimate cross-shop for integrators evaluating an 8MP outdoor turret.
In This Guide
How do the imaging specs compare?
The ACTi Q550 uses two 4MP sensors behind dual fixed 4mm f/1.0 lenses, delivering a combined 180° panoramic field of view from a single housing. Each sensor is a 1/2.7" chip with Extreme WDR rated at 130 dB and Adaptive IR LEDs operating at 850nm with an IR range of 50m. Minimum illumination reaches 0.0005 lux at F1.0 (AGC on), reflecting the very fast f/1.0 aperture. The Vivotek IT939-HTVW-1Y pairs a larger 1/1.8" sensor with a motorized varifocal 2.8–12mm lens (remote focus capable), covering a single adjustable scene rather than a fixed panoramic arc. Its WDR is listed as WDR Pro with no dB value specified. IR range is 40m with a supplemental warm-light illuminator reaching 30m.
On low-light performance, the Q550's 0.0005 lux at F1.0 is numerically stronger than the IT939-HTVW-1Y's 0.04 lux at F1.6 (color) and 0.005 lux at F1.6 (B/W), though the IT939-HTVW-1Y can reach 0 lux with IR active. The IT939-HTVW-1Y's 1/1.8" sensor is physically larger than the Q550's 1/2.7" chips, which typically benefits dynamic range and color fidelity in daylight. Maximum frame rate for the IT939-HTVW-1Y is specified at 15 fps; the Q550's maximum frame rate is not stated in the provided specifications.
What about installation and environment?
The Q550 carries an IP67 rating (dust-tight, temporary immersion) and IK10 impact resistance in a metal housing, operable from -40°C to 60°C. The IT939-HTVW-1Y is rated IP66 (dust-tight, powerful water jets) and IK10, with an operating range of -30°C to 50°C (IR off) or -30°C to 45°C (IR on). The Q550's -40°C lower bound is a meaningful advantage for cold-climate installations where the IT939-HTVW-1Y's -30°C floor may be insufficient without supplemental heating.
Both cameras support single-cable PoE 802.3af deployment. The Q550's spec sheet lists DC 12V or PoE (IEEE 802.3af) as power inputs, while the IT939-HTVW-1Y is specified as PoE 802.3af Class 3 with a maximum draw of 12.4W (9.6W with IR off). The Q550 also appears in specifications referencing PoE+ (802.3at), though the primary datasheet lists 802.3af—installers should verify the actual power budget requirement before switch selection. The Q550 supports pole and pendant mounting; the IT939-HTVW-1Y is listed for wall/soffit turret mounting. The IT939-HTVW-1Y includes an industrial microSD card (up to 512GB) pre-installed; the Q550 does not list on-board storage.
Which fits your VMS and analytics better?
The Q550 is ONVIF Profile S, Profile G, and Profile T certified and includes an on-board Deep Learning Processing Unit (DLPU) running people detection, vehicle detection, line crossing, and intrusion protection—edge analytics that reduce VMS server load and minimize false alerts. The IT939-HTVW-1Y is ONVIF-compliant (profile level not specified) and lists Object Analytics; detailed analytics categories are not enumerated in the provided specifications. Both cameras offer two-way audio with built-in microphone and speaker. The Q550 additionally lists line-in and line-out interfaces; the IT939-HTVW-1Y specifies full-duplex two-way audio but does not list separate line-in/line-out ports.
The IT939-HTVW-1Y includes notable cybersecurity features—secure boot, signed firmware, HTTPS/TLS encryption, and video encryption—that are not listed in the Q550's provided specifications. It also supports WebRTC and RTSP/RTP/RTCP in addition to ONVIF, and ships with up to 512GB industrial-grade microSD storage pre-installed, enabling edge recording without a dedicated NVR. The IT939-HTVW-1Y carries a stated 10-year warranty; no warranty term is listed for the Q550 in the provided specifications.
Which should you choose: the Q550 or the IT939-HTVW-1Y?
Our take: The Q550 is the stronger choice when panoramic 180° coverage, colder operating environments, or superior low-light sensitivity are the primary requirements. Its dual-sensor design replaces two single-scene cameras on one PoE run, its -40°C cold floor outperforms the IT939-HTVW-1Y's -30°C limit by 10°C, and its 0.0005 lux minimum illumination at F1.0 undercuts the IT939-HTVW-1Y's 0.04 lux color threshold by roughly 80×. The IT939-HTVW-1Y is the better fit when scene flexibility, long-term TCO, or cybersecurity compliance drive the decision: its motorized 2.8–12mm varifocal lens allows remote reframing without a site visit, its 1/1.8" sensor is larger and may yield stronger daylight image quality, it ships with 512GB edge storage pre-installed, and it carries a stated 10-year warranty versus an unstated term for the Q550. Specify the Q550 for wide-area or extreme-cold perimeter work; specify the IT939-HTVW-1Y for single-scene deployments requiring lens flexibility, onboard recording, or hardened cybersecurity posture.
Side-by-Side Comparison
Spec-for-spec, from manufacturer data.
| Specification | ACTi Q550 | Vivotek IT939-HTVW-1Y |
|---|---|---|
| Resolution | 8MP (dual 4MP sensors) | 8MP (3840 × 2160) |
| Image Sensor | 1/2.7" (×2) | 1/1.8" |
| Lens / Focal Length | 4mm f/1.0 fixed (×2) | Motorized varifocal 2.8–12mm, remote focus |
| Field of View | 180° panoramic (2-sensor) | Single scene (angle not specified) |
| Min Illumination | 0.0005 lux @ F1.0 (AGC on) | 0.04 lux @ F1.6 (Color); 0.005 lux @ F1.6 (B/W); 0 lux (IR on) |
| IR Range | 50m (850nm Adaptive IR) | 40m IR; 30m warm light |
| WDR | Extreme WDR (130 dB) | WDR Pro (dB not specified) |
| Max Frame Rate | Not specified | 15 fps |
| Video Compression | H.265; H.264; MJPEG | Not specified in provided specs |
| IP Rating | IP67 | IP66 |
| IK / Impact Rating | IK10 | IK10 |
| Operating Temperature | -40°C to 60°C | -30°C to 50°C (IR off); -30°C to 45°C (IR on) |
| Power Input / PoE Class | PoE 802.3af / DC 12V (802.3at also referenced) | PoE 802.3af Class 3; 12.4W max |
| Edge Storage | — | microSD/SDHC/SDXC up to 512GB (pre-installed) |
| Audio | Two-way; Built-in mic; Line-in; Line-out | Two-way full duplex; Built-in mic; Built-in speaker |
| Edge Analytics | DLPU: People Detection, Vehicle Detection, Line Crossing, Intrusion | Object Analytics (categories not enumerated) |
| ONVIF | Profile S; Profile G; Profile T | Yes (profile level not specified) |
| Cybersecurity | Not specified | Secure boot; Signed firmware; HTTPS/TLS; Video encryption |
| Weight | Not specified | 780 g |
| Warranty | Not specified | 10 years |
Frequently Asked Questions
Which should you choose: the Q550 or the IT939-HTVW-1Y?
The Q550 is the stronger choice when panoramic 180° coverage, colder operating environments, or superior low-light sensitivity are the primary requirements. Its dual-sensor design replaces two single-scene cameras on one PoE run, its -40°C cold floor outperforms the IT939-HTVW-1Y's -30°C limit by 10°C, and its 0.0005 lux minimum illumination at F1.0 undercuts the IT939-HTVW-1Y's 0.04 lux color threshold by roughly 80×. The IT939-HTVW-1Y is the better fit when scene flexibility, long-term TCO, or cybersecurity compliance drive the decision: its motorized 2.8–12mm varifocal lens allows remote reframing without a site visit, its 1/1.8" sensor is larger and may yield stronger daylight image quality, it ships with 512GB edge storage pre-installed, and it carries a stated 10-year warranty versus an unstated term for the Q550. Specify the Q550 for wide-area or extreme-cold perimeter work; specify the IT939-HTVW-1Y for single-scene deployments requiring lens flexibility, onboard recording, or hardened cybersecurity posture.
Is the Q550 or IT939-HTVW-1Y better for low-light performance?
Based on the provided specs, the Q550 reaches 0.0005 lux at F1.0 (AGC on) versus the IT939-HTVW-1Y's 0.04 lux at F1.6 (color) and 0.005 lux at F1.6 (B/W). The Q550's faster f/1.0 aperture gives it a substantial edge in starlight or near-dark conditions. The IT939-HTVW-1Y can reach 0 lux only when its IR illuminator is active.
Can either camera record locally without an NVR?
The IT939-HTVW-1Y supports microSD/SDHC/SDXC cards up to 512GB and ships with an industrial-grade card pre-installed, enabling standalone edge recording. The Q550's provided specifications do not list any on-board storage capability, so it would require a VMS or NVR for continuous recording.
Which camera covers a wider field of view?
The Q550 uses two fixed 4mm sensors arranged to deliver a combined 180° panoramic field of view from a single housing. The IT939-HTVW-1Y uses a single motorized 2.8–12mm varifocal lens covering one adjustable scene; its specific field-of-view angle is not stated in the provided specifications. For replacing multiple fixed cameras on a wide perimeter, the Q550's multi-imager design has a structural advantage.
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