BBot V3 Industrial camera trade study

Product	Megapixel	Image	Sensor	Price
SVS-Vistek shr661	127	Open	Sony IMX661 sensor 3.45 μm x 3.45 μm 14-bit output Diagonal 56mm format M72x0,75 lens mount Fixed focus	$18,000
Phase One 50MP Camera iXM-50	50	Open	Medium format Fixed focus but autofocus is possible	$21,000
GV-77U5WP	44		onsemi XGS 45000 12-bit output 3.2 µm x 3.2 µm Super 35mm format Fixed focus TFL lens mount	$7,590
LUCID Vision Labs Atlas™ ATL314S-CT	31		Sony IMX342 APS-C sensor format 3.45 μm x 3.45 μm Fixed Focus	$6,314
Basler ace 2 a2A5328-15ucPRO	24		Sony IMX540 1.2” sensor format 2.74 μm x 2.74 μm C-mount Fixed focus	$2,419
Sony a9 III Mirrorless Camera	24		Sony full frame sensor Stacked sensor FE mount Autofocus	$5,998

Summarized table with key differences:

The table below compares concrete metrics from each of the cameras. The most obvious column is the field of view, which can be compared with the system requirements. Depending on the physical sensor size, the lens mount varies which again decides which lenses are supported. When selecting the right lens, keep an eye out for 1) mount, 2) supported pixel size (which translates to optical resolution), 3) max supported sensor size. Then, based on the optimal focal length (determined by the ground sampling distance of 8 pixels per mm as well as the desired distance of 1.6 meters between camera and plant), find a lens which has a comparable focal length.

Comparison of set of cameras with theoretical levels of diffraction. In short, the level of diffraction is determined by the diameter of the resulting airy disk relative to the physical pixel size. As the airy disk starts covering multiple pixel lengths, a blurring effect will appear. As always, since the image sensor is divided into color specific pixels using a 2x2 bayer pattern, blurring will not be visible before the disk exceeds the size of at least to pixels. The table lists the diameter of the airy disk at given relative apertures (F-number). Although the diffraction is determined by the physical aperture dimensions, a change in focal length will magnify this effect onto the sensor. Because of that, we can disregard lens choices here, compare directly with the image sensor. Green: Airy disk < 2.5x pixel width. No visible blur from diffraction. Yellow: 2.5x < Airy disk <5x pixel width. blur might be visible. Red: Airy disk > 5x pixel width. blur is visible. The numbers below each camera sensor denotes the pixel width of the given sensor.

Comparison of depth of field in mm of different camera sensors without regards to the lens' focal length. Green denotes depth of field larger than 15 cm. Yellow denotes depth of field smaller than 15 cm. In this table, I have defined depth of field given a Circle of Confusion set to 2x the pixel depth of each camera.

Comparison of transmitted light per pixel based on a required aperture for 20 cm depth of field relative to CoC of 2x pixel width at a distance of 1.6 meters from camera to plant. Due to the difference in physical pixel size, the significant difference is relative aperture is more or less cancelled out.

Notes Jan 24, 2024

We need more space because of increased image size

• Focus

• API template scripts to interface with the camera - @Mikah Pinegar to look into that

• Company to get back on sensor options

• Any electrically adjustable lens? This doesn’t mean automatic focus regardless, these cameras don’t have auto focus

• Process with manually adjustable lens:

  • Define at what distance we need the lens from the tallest plant - We can calculate this - The camera will be 1.5 to 2 m - We need to define the exact number

  • Technician enters average height of the canopy at the beginning of the run changes the Z axes according to the canopy height (estimate)

  • Set the focus at a range that gives us the biggest FOV, what distance from the plant that is

  • Practical aperture setting:

  • Minimum depth of field:

  • We want to not adjust the lens, the user just changes the Z axis

• Can we achieve the lighting for this sensor? The one that Soren suggested is not in production anymore, we would have to get it second hand - Mark can build a flash for a later upgrade.

• We need to be able to map out where the pots are

Notes Jan 25, 2024

• SDK (Mikah): we would have to use c++ language (@Priya Jakhar best candidate for the task) - Works with Mac, Windows, Linux - Documentation looks good, well maintained

• Mechanical data sheets (Mark): mechanical, good documentation, easy to interface - You can attach 4 different flashes

• Flashes (Soren): No obvious choices for now

  • Flash tubes (We’ll have to build from scratch)

  • LEDs

  • Ring flash https://www.ebay.com/itm/256381363536?hash=item3bb1852550:g:s8MAAOSwOZNlqUjo

• Lens (Soren): needs to share more information with camera vendor to get lens recommendation

• Some specs that we want on the camera (mark):

  • not poe version

  • 10 Gig port version

• To purchase

  • Get a quote from the camera company to give to @Susan

  • Machine Vision Camera (@Chris Reberg-Horton @Susan ) - Sole sourcing

  • Ring flash (@Søren to get flash link)

  • Lens (@Søren to get recommendation from the camera manufacturer for both cameras that use this sensor) - Define the lens before placing a camera order