Elphel Eyesis4Pi

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The newer version EYESIS4PI-26-393 is available. Jump to Eyesis4Pi-393 article.


  • new 10393 system boards
    • faster recording
    • more powerful
  • more compact - the pole is 2 times shorter

Compare 3D models:

NEW Eyesis4PI-26-393 3D
Eyesis4PI-26 3D


Dimensions (mm)
Head Contents Schematic
Pole Contents Schematic
Assembly Drawing, Download JPEG,PDF
FOV of sub-cameras in Eyesis4Pi, color shows time of acquisition (from red to blue):1-8 horizontal sensors; 1t-8t top sensors;1b-8b bottom sensors

Elphel Eyesis4Pi is an open hardware / free software panoramic camera solution that is able to capture high-resolution - 64 MPix total (120 MPix before stitching) - 360° panoramas at a rate up to 5 frames per second at full resolution. It is the successor of the Elphel Eyesis. Images are recorded to 8 solid-state-discs (Eyesis4Pi Data Storage) which can store up to 11 hours of footage at full resolution. Meta-data like GPS-coordinates (geotags), viewing direction, movement speed, etc. are directly embedded into the images EXIF fields. Eyesis4Pi uses 24+2 sensor-front-ends and high-grade lenses that are triggered simultaneously with microsecond accuracy to ensure a full homogeneous spherical snapshot.

Usage Scenarios

The system was designed to be small and lightweight with a minimal distance between the entrance pupils (46.5mm) to achieve lowest possible parallax.

The primary usage scenario is to mount Eyesis4Pi on the roof of a vehicle. When driving at 50 mph (22.3 m/s) and recording at 5 FPS a full panorama is captured every 4.46 meters.

Operation & Monitoring

Eyesis4Pi is controlled from a laptop, via a web-based interface (Eyesis4Pi GUI). Which also displays real-time previews of your captured panorama footage.

Eyesis is supplied with 110V/220V AC and can be used with car power adapter (inverter), when mounted on a car roof. Power consumption is about 50W.


4π (or 4Pi) corresponds to a full spherical (360°x180°) field of view in steradians.

There are 2 version of the camera Eyesis4Pi with 24+2 image sensors and full spherical field of view and Eyesis3Pi with 16+2 sensors (without 8 bottom modules) with slightly smaller field of view.

Comparison between Eyesis and Eyesis4Pi



(Eyesis 3Pi without 8 bottom modules)

Combined field of view (steradians)
4*π (3*π)
Number of image sensors
24+2 (16+2)

Angular resolution +/-30° from the horizon
Angular resolution +30° to +90°(zenith)
≥4.2Mpix/steradian 1
Angular resolution -30° to -90°(nadir) none ≥4.2Mpix/steradian (none) 1
Combined megapixels 45.0 120.0 (80.0)
Combined megapixels (w/o overlapping areas) 34.0 64.0 (48.0)
Combined megapixels (w/o overlapping areas,
worst case resolution)
29.0 52.8 (39.6) 1,2
Distance between entrance pupils
of adjacent horizontal lenses
34.5mm 46.5mm
Distance between entrance pupils
of horizontal and top/bottom lenses
75mm 50mm 3
Maximal frame rate 5fps 5fps 4
Maximal recording data rate 48MB/s 128MB/s (96Mb/s)
Maximal direct network data rate 30MB/s 80MB/s (60MB/s)
GPS receiver external, USB External/internal, USB/RS232
GPS pulse-per-second input no

IMU none ADIS163xx,ADIS164xx
Data unload removable SSD in cradles eSATAx2
Storage devices type 2.5″ SSD 1.8″SSD
Number of storage devices 3
8 (6)


  1. Angular resolution per pixel differs in the sub-camera FOV, minimal resolution is used.
  2. Zenith area for Eyesis (covered by fisheye lens) is calculated separately.
  3. For Eyesis the distance is measured from the entrance pupil of the horizontal lens to that of the top fisheye, for Eysis-4pi – to the entrance pupil of the lens immediately above/below the first one.
  4. Frame rate may be limited by the recording (or network if the SSD are not used) datarate for high compression quality (>0.3 bytes/pixel), required for the aberration correction.


We have developed full calibration process and post-processing software to compensate for optical aberrations, allowing to preserve full sensor resolution over the camera FOV, and distortions – for precise pixel-mapping for photogrammetry and 3D reconstruction. Check out this Elphel Development Blog post for more details.

Tech specs

Eyesis4Pi Camera

  • 24x Color 5MPix CMOS sensors in array that covers the sphere
  • 2x Color 5MPix CMOS sensors in the pole that make stereo pairs with corresponding sensors in the camera head.
  • Resolution - 64MPix (120MPix before stitching)
  • Up to 5 FPS at full resolution (120Mpix) - only if equipped with SSDs
  • Web-based GUI
  • GPS powered geo-tagging
  • IMU powered 3D inertial measurement
  • Precise image capture synchronization
  • RAW or compressed image formats
  • High resolution lenses: 26x M12 lens mount
  • Very small parallax - distance between entrance pupils: 46.5 mm
  • Weatherproof camera body and camera pole
  • Highly Customizable

Eyesis Data Storage

  • located inside weatherproof camera pole
  • 9x 128 GB - 1.8" - SSDs
  • Enough space for 3 hours of full Resolution/FPS footage (depending on quality settings and actual image content)

Eyesis4Pi Computer

The Eyesis Computer is a high-end-workstation in a small form factor. It is intended for image post-processing and not required for recording footage.

It comes with all Elphel developed software and tools required for processing panoramic images preinstalled.

  • Small form factor Shuttle PC
  • Intel Core i7-950 Quad-Core Processor
  • 16 GB DDR3 RAM
  • GeForce GTX 465 (Fermi) 1GB
  • 2 TB HDD

Tech Specs of a Single Image Sensor (Eyesis4Pi uses 24+2 of these, Eyesis4Pi-24 uses 24, and Eyesis4Pi-16 uses 16)

Color Image Sensor 1/2.5" bayer-pattern CMOS
Effective number of pixels 2592x1936 (5,018,112 pixels)
Aspect Ratio Chip 4:3, Region of interest freely adjustable in 16 pixel steps
Sensor Output 12 Bit ADC
Sensor Features Region of interest, on-chip binning and decimation
Dynamic Range 70 db (76 db at 2x2 binning)
Electronic Shutter 1 us to "very long" (~3h) in 1us steps
Gain Analog & Digital (0 db to 12 db continuous)

Image Samples

More Information


Elphel Development Blog:


Why are there 9 SSDs and not just a single bigger one?

There are 26 sensor-front-ends. There are 9 system boards each connected to 3 sensor-front-ends and a one SSD. The shots of a single panorama are split up on 9 SSDs. 3 images to SSD1, 3 images to SSD2, 3 images to SSD3... and the last 2 - to SSD9

Can I also use Eyesis4Pi with HDDs instead of SSDs?

We initially tested the system with HDDs but due to strong vibrations when using Eyesis mounted to a car roof we experience massive write-rate drops with HDDs. After we switched to SSDs all these problems were gone. If your Eyesis application does not involve bumby roads or vibrations HDDs should work just fine though.

How do I unload the data from Eyesis4Pi?

The camera pole has 2 eSATA ports in a weatherproof sealed connector. With this connector you can connect to the SSDs inside the camera pole like to any external hard-drive with any laptop/computer.

What software do I need on my laptop/computer to control Eyesis?

Eyesis GUI requires a locally running webserver (apache2 + PHP5) and the Eyesis User Guide software.

How do I connect my laptop/computer to Eyesis and how do I control image recording?

The Eyesis4Pi hosts a Gigabit Ethernet switch so all you need is one Ethernet cable from the camera pole hose to your laptop/computer.

The Eyesis GUI is completely browser based so after you connected to the network you just start a browser type in the correct URL and you are ready to go.

See Eyesis4Pi User Guide