Hanwha SLA-T-M1250DN 12MP DC-Iris Megapixel Lens
The Hanwha SLA-T-M1250DN is a professional varifocal lens engineered for 12MP and 4K surveillance cameras. It delivers a 12-50mm focal range with DC auto-iris control, enabling consistent exposure across dynamic lighting conditions without manual adjustment. The compact form factor—under 64mm TTL—fits tight spaces where standard lenses won't, yet maintains the optical performance required for large-area monitoring and facial detail capture.
Key Features
- 12-50mm Varifocal Focal Length: Covers both wide-area overview and targeted close-range detail in a single lens. The 2.0m minimum focus distance handles typical indoor and outdoor surveillance layouts without requiring multiple lens swaps during initial deployment.
- DC Auto-Iris Control: Responds to changing light throughout the day without user intervention. This means backlit loading docks, bright storefronts, or dimly lit warehouse aisles all receive proper exposure automatically—no need for separate cameras or manual stops.
- 12MP Native Resolution Support: Captures full detail from modern megapixel sensors. In practice, this supports 4K frame rates and allows post-installation digital zoom during review without significant quality loss.
- IR Corrected Day/Night Operation: Optical correction for infrared pass-through means images remain sharp when the camera switches to IR illumination at night. This is more than "night vision capable"—it ensures usable detail in darkness, not just shadow outlines.
- Compact 64mm TTL Design: Fits recessed mounts, compact turret housings, and covert installations where depth budget is tight. Saves you redesigning enclosures or switching to shorter lenses that would shrink your field of view.
- CS Mount Standard: Direct compatibility with the broadest range of IP cameras and sensor modules on the market. No mount adapters, no registration tolerances—install and focus.
- Wide Aperture Range F/1.8–F/2.4: The fast F/1.8 opening at 12mm (widest focal length) gathers more light, which matters in low-light scenes before IR activates. The narrower F/2.4 at 50mm maintains shutter speed and reduces optical aberrations at the telephoto end.
- 30cm Iris Control Cable: Flexible wiring lets you route the DC iris connection cleanly in camera housings or turret designs without cable strain.
Integration & Compatibility
The SLA-T-M1250DN works with any CS-mount camera that supports DC iris control—a standard feature on Hanwha IP cameras and most professional surveillance platforms. If you're upgrading from older fixed-lens systems or retrofitting a surveillance array, this lens integrates without firmware updates or driver changes. Pair it with a network video recorder or edge-based storage system; the lens itself is passive and adds no bandwidth or processing load.
Operating Environment
The lens operates reliably from –20°C to +60°C (–4°F to +140°F) with less than 70% humidity—suitable for indoor facilities, covered outdoor structures, and temperate climates. Storage tolerance extends to –30°C to +70°C, so it survives warehouse shelving or shipping in uncontrolled spaces. For truly harsh outdoor duty (direct rain exposure, freeze-thaw cycles, or high humidity), verify that your camera body carries an IP67 or IP68 rating; the lens itself does not have an independent environmental rating.
Frequently Asked Questions
Q: What camera brands does the SLA-T-M1250DN work with?
A: Any camera with a CS mount and DC iris control input. This includes Hanwha models, as well as many third-party cameras from manufacturers supporting standard CS mounts. Verify your specific camera body supports DC auto-iris before ordering.
Q: Can I use this lens on an indoor and outdoor camera?
A: The lens itself operates indoors and outdoors under normal conditions (–20°C to +60°C, <70% humidity). However, for outdoor mounting, the camera body must carry at least IP66 weather sealing. The lens has no independent IP rating.
Q: What is the minimum focus distance?
A: 2.0m (approximately 6.5 feet) across the entire 12-50mm focal range. This is typical for professional surveillance varifocals and suits most facility layouts. If you need closer focus, consider fixed short-focal-length alternatives.
Q: Does the DC iris cable length matter for installation?
A: The included 30cm cable offers moderate routing flexibility within camera housings and mounts. Longer runs require an external iris driver module (not included). Plan cable paths during mount selection to avoid sharp bends.
Q: Is the SLA-T-M1250DN suitable for facial identification at distance?
A: At 12MP with a 50mm telephoto end, it captures good facial detail at moderate range (roughly 15–25 meters depending on lighting). For longer-distance identification, consider a higher megapixel camera body (16MP or greater) paired with this lens, or a dedicated PTZ lens with greater optical zoom.
Q: What happens if I use this lens on a non-megapixel camera?
A: It will work mechanically, but you lose the advantage of the 12MP design. The lens is optimized for full-resolution sensors. Using it on a 2MP or 5MP camera underutilizes the optics and adds unnecessary cost.
Marty AllisonPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The SLA-T-M1250DN is one of those lenses that solves a real problem: you need varifocal range for flexible deployment, but your mount or housing won't accept a standard 80mm+ lens. The sub-64mm TTL is genuine—I've confirmed it against data sheets from comparable Hanwha lines—and it doesn't come at the cost of optical performance. The DC auto-iris handling is straightforward electronics that integrate cleanly with any camera that supports standard iris control, no firmware nonsense required.
Technical Highlights:
- F/1.8 @ 12mm aperture: Delivers measurably better low-light performance than typical F/2.0 designs. In a dimly lit warehouse or retail aisle before IR activates, that extra stop means the difference between a usable 30 fps exposure and a dark, grainy frame. Test this in your actual lighting before deployment.
- IR-corrected optics: Not every lens is. Standard designs shift focus when the IR filter flips out. The SLA-T-M1250DN compensates, so your sharpness doesn't degrade when the camera switches to night mode. Matters most in areas with borderline lighting (dusk, shaded outdoor zones).
- 2.0m minimum focus: Respectable for a 12-50mm varifocal. Means you can use this on overhead mounts or recessed domes without blind spots in the near field. Beyond 50 feet, focus becomes less critical anyway.
Deployment Considerations:
- Verify your camera body actually supports DC iris control. Some budget or older models don't. Requesting the camera's spec sheet is faster than discovering this on-site.
- The 30cm iris cable is adequate for most compact housings but gets tight if you're routing through strain-relief conduit or multiple 90-degree turns. Plan the path during design, not during installation.
- This lens will not fix a poorly chosen camera body. If your megapixel sensor is noisy at high ISO or lacks sufficient dynamic range for your lighting environment, a better lens won't rescue the image.
Fit this lens into mid-size facility upgrades where you're retrofitting turret or compact dome cameras and need flexibility without redesigning the mounting infrastructure. Pair it with a 12MP sensor and you get genuinely useful detail across a typical 15-meter indoor or well-lit outdoor perimeter. Don't force it onto a low-megapixel body or expect it to work miracles in extreme low-light without proper IR support from the camera.
