The ACSL SOTEN ships as one airframe with four interchangeable camera payloads, and the payload you choose matters more than almost any other decision you will make about the aircraft. A standard camera and a thermal payload turn the same drone into two different tools serving two different departments. This article walks through all four options, what each one actually does, and which mission each is built for, so you can spec the aircraft correctly the first time.
You are not choosing between four drones. You are choosing which sensors your team needs in the air, and buying an extra payload instead of an extra aircraft.
One aircraft, four payloads
Every SOTEN camera mounts through the same one-touch swappable interface. No tools, no disassembly, no recalibration flight. A crew can land, change payloads, and be back in the air in the time it takes to swap a battery. That design is the reason a single SOTEN can serve a fire department's night operations on Friday and a public works mapping request on Monday.
Here is how the four compare at a glance.
| Payload | Primary sensor | Captures | Built for |
|---|---|---|---|
| Standard Camera | 1-inch, 20 MP | 20 MP stills, 4K video | Mapping, documentation, general survey |
| Optical Zoom Camera | 1/2.3-inch, 12 MP | 2.5x optical zoom, 4K video | Standoff inspection and identification |
| SAMO Thermal-Optical | 640 x 512 radiometric thermal plus 64 MP visible | Thermal and visible imagery | Search and rescue, fire, night operations |
| Multispectral Camera | 1-inch, 20 MP | 16-bit TIFF stills, three spectral bands | Crop health and vegetation analysis |
Standard Camera: the default for mapping and documentation
The Standard Camera carries the largest sensor in the lineup: a 1-inch, 20 MP sensor with a fixed 28 mm equivalent lens at f/2.8 to f/11. It shoots 5448 x 3632 stills in JPEG, DNG, or both simultaneously, and records 4K video at 30fps.
The specification that matters most for survey work is the mechanical shutter. A mechanical shutter exposes the entire frame at once. Electronic rolling shutters read the sensor line by line, which can skew subjects while the aircraft is moving. For photogrammetry and mapping passes, that difference shows up directly in the quality of your reconstructed model.
Who should choose it: public works and engineering departments doing site documentation, surveyors building orthomosaics and 3D models, insurance and claims teams photographing damage, and any agency that needs one general-purpose camera to cover most of its flying.
Optical Zoom Camera: reach without getting close
The Optical Zoom Camera trades sensor size for reach. It pairs a 1/2.3-inch 12 MP sensor with an 18 to 45 mm equivalent lens, giving 2.5x optical zoom, and records 4K video at 30fps. Optical zoom preserves image quality across the range, which is the difference between reading a serial plate and guessing at it.
Reach changes how close the aircraft has to fly. On a live incident, over water, near an energized substation, or above a crowd, the safest distance is often not the distance that gives you the best picture. Zoom resolves that conflict.
Zoom versus resolution. The Standard Camera's 20 MP sensor lets you crop into a wide shot after the flight. The Zoom Camera lets you frame the detail live, while the operator is watching. If your crew needs to make decisions in the air rather than at the desk, the zoom is the better fit even though its sensor is smaller.
Who should choose it: utility and infrastructure inspectors working bridges, towers, and lines, law enforcement doing overwatch and identification at a standoff distance, and inspection crews who need to read labels, gauges, and defects without closing the gap.
SAMO Thermal-Optical Payload: seeing heat and detail together
SAMO is the dual-sensor payload: a radiometric 640 x 512 Teledyne FLIR Boson thermal core alongside a 64 MP visible camera in one gimbal. The thermal side resolves temperature differences below 20 mK typical, with ±5°C accuracy across the 0°C to 100°C range. Because it is radiometric, it reports actual temperature values per pixel rather than showing relative heat only.
The visible sensor matters more than it first appears. Thermal imagery alone can be hard to interpret and harder to present later, whether to a commander, a property owner, or a court. Having a 64 MP visible frame of the same scene gives context that a thermal frame by itself cannot.
±5°C accuracy is appropriate for locating heat sources, tracking spread, and finding people and anomalies. It is not a substitute for calibrated contact instruments where a precise temperature reading is the deliverable.
Who should choose it: search and rescue teams working at night or in heavy cover, fire crews assessing hot spots and spread, law enforcement running night operations, and utility inspectors looking for overheating components on lines, transformers, and solar arrays.
Multispectral Camera: measuring plant health
The Multispectral Camera is the outlier in the lineup, and the one most often bought for a single specific purpose. It uses a 1-inch 20 MP sensor behind a field-attachable triple bandpass filter that isolates 550 nm green, 680 nm red, and 850 nm near-infrared. Output is 16-bit TIFF, which carries the bit depth that analysis software needs to calculate NDVI and similar vegetation indices.
Healthy vegetation reflects near-infrared strongly and absorbs red. Comparing those two bands is how you find stress in a field before it is visible to the eye, and it is why a multispectral pass over a crop can be worth more than a far higher resolution visible photograph of the same acreage.
The Multispectral Camera captures stills only. It does not record video. Live view is available to the operator at Full HD, but nothing is written to the card except TIFF frames. If your workflow needs video, plan on carrying a second payload.
Who should choose it: agricultural operators and agronomists doing crop scouting, university and agency research programs, conservation and land management groups monitoring vegetation, and environmental compliance teams documenting site conditions over time.
How to choose
Three questions usually settle it.
- What do you need to see that you cannot see now? Heat points to SAMO. Plant stress points to multispectral. Detail at a distance points to the zoom. Everything else points to the standard camera.
- Are you making decisions in the air or at the desk? Live decision-making favors zoom and thermal. Post-flight analysis favors the larger sensors on the standard and multispectral payloads.
- Do you need imagery, or do you need measurements? The standard and zoom cameras produce imagery. SAMO produces temperature values. The multispectral camera produces spectral data. Measurement work has a right answer and it is usually not the general-purpose camera.
Most departments we work with start with one payload and add a second within the first year, rather than buying a second aircraft. The swappable design is what makes that the cheaper path.
What all four have in common
- One-touch swappable mounting on the same SOTEN airframe
- 3-axis stabilized gimbals with ±0.02° control accuracy
- microSD recording, up to 512 GB on the optical, zoom, and multispectral payloads
- NDAA compliant, manufactured by ACSL in Japan
- IP43 or better ingress protection when installed on the aircraft
Common questions
Can I fly more than one payload at a time?
No. The SOTEN carries one payload per flight. Swapping is fast enough to change payloads between flights on the same battery rotation, but a single sortie captures from one camera.
Is the zoom camera's 12 MP sensor a downgrade from the standard camera?
On paper, yes. In practice they answer different questions. The 1-inch 20 MP standard sensor produces better image quality and better mapping output. The 1/2.3-inch 12 MP zoom sensor produces a usable picture of something far away. Choose by the mission, not by the pixel count.
Which payload is right for solar or electrical inspection?
SAMO. Failing cells, loose connections, and overheating components show up as thermal anomalies well before they are visible. The 64 MP visible sensor in the same payload then documents exactly which panel or component it was.
Do the payloads need different controllers?
The standard, zoom, and multispectral cameras operate with the SOTEN's smart controllers. SAMO operates with the TAITEN Smart Controller and the ACSL TAKEOFF ground control app. If you are adding SAMO to an existing SOTEN, confirm your controller before ordering.
Are all four payloads NDAA compliant?
Yes. ACSL manufactures the SOTEN and its payloads in Japan. As we covered in our overview of the aircraft, NDAA compliance refers to the manufacturer and its supply chain rather than a single certification on the camera itself.
If you are new to the platform, start with our overview of why agencies that cannot fly DJI are choosing the SOTEN, then come back to pick a payload. For the cameras themselves, see the Standard Camera, the Optical Zoom Camera, the SAMO Thermal-Optical Payload, and the Multispectral Camera. If you are weighing two options against a specific mission, contact us and we will walk through it with you.
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