Setup

Remote into the Minicomputer

Setup Tailscale (a piKVM)

1. Priya Jakhar needs to send you an invitation to your email

2. Once the invite has been accepted, create an account with your github account

3. Follow the on-screen instructions to setup tailscale

Connecting to the Minicomputer

4. Once you’re tailscale account is setup, go to your dashboard and you should see your account and the benchbot account.

5. The benchbot account needs to be “connected”, indicated by a green bullet

6. Then copy and paste the mini computers IP address into a new browser window address bar.

7. You need to sign into the KVM using a username and password and then sign into the mini computer “benchbot” user with another password. These 2 passwords should be provided to you privately.

To take an image from the mini-computer

1. Open up a browser on the mini computer and copy and paste this into address bar:

localhost:5000/image

2. You should see an image appear in the browser window

Flash Setup

1. Set up the flash with the desired settings, as settings influence the flash duration. My assumptions are:

   1. Manual mode

   2. 1/1, 1/2+0,3-0,6 or 1/2 flash power level

   3. Not sure about "stable color temperature" and it's impact to the frequency at which the flash can fire.. Should be tried out. We'd like a constant color temperature, but not sure what the downside is here, since it's not turned on always.

      1. stable color temperature should be on

   4. "stand by" should be turn off, or set to something like 120 min.

   5. "Delay flash" should be turn off

   6. Modeling lamps should be turned off

   7. Observe the flash duration time t=0.1. This is presumably done with the "TIMES" function of the flash.

Camera Setup/Config

1. Turn off all auto settings.

   1. This includes exposure times, gains, white balancing, etc.

2. Set exposure time to half of t0.1 from the flash. Pay attention to difference in units.

3. While you have a non-changing level of ambient light:

   1. Capture a series of images with a varied camera-set delay between flash trigger and image exposure. The entire scene has to stay constant.

   2. If the images are overexposed in this experiment, modify the aperture on the lens accordingly.

   3. Note the delay that resulted in the brightest image and put that delay into the camera.

4. Color and focus calibration.

   1. Place a color checker below the camera, preferably the big one. If the camera cannot move in the z-axis, place the color checker 15 cm above the pot soil level.

   2. Refocus the camera to ensure that focus is accurate. This is done with the color checker by zooming in on the millimeter markers. Open up the aperture all the way and repeatedly make tiny adjustments -> image capture -> zoom in and evaluate until focus is just right.

   3. Reset the aperture to an appropriate level based on the brightness of the image at the designated flash power.

   4. Capture a good quality image of the colorchecker to be used for color calibration (specifically to determine the color calibration matrix used for DNG-formatting of the images)

To determine the effect of the stable color temperature, it makes sense to run a stress test with and without it at our desired flash power. That would also help answer whether the flash will bottleneck the bbot at the given power level (edited) 

Protocols

Camera testing

• place the camera lens 170cm above the pot surface

• place colorchecker card 15 cm above the pot surface

• set the aperture to the lowest number (f/4)

• adjust exposure

• start finding the right focus so that the milliliter scale on the colorchecker are incredibly clear, adjust by millimeter. For example here is how the scale bar should look -

• after the right focus has been identified, set it using the set screw

• now adjust aperture and exposure as needed

• Set max camera height ~1.7 meters above pot top ->

• set focus according to the color checker at aperture=F4 ->

• Increase flash power + increase F-number to around 10.

• Set exposure time to 250 uS.

• Modify aperture up or down until an appropriate exposure level is reached.

• if too much light, increase aperture to f/11 or f/12

• as f number increase, image quality generally increases but as it get too high image quality decreases

• The camera should stay at 170 +- 5 cm

• only moving up as plant grow taller

• generally don’t want images to be too bright because you risk over exposure with flowers or wet pots

• only thing that changes would be the height of the camera (z-axis) in the upward 20cm direction. The camera should only move up with the increase height of plants

• adjust strobe delay 50, 100, 150, 200 while the exposure time stays at a constant 100

  • if it’s darker 50, decrease to 25, then if it’s still darker we stay at 0 and move exposure back to 250

• use a second color checker card at pot level to confirm that images are in focus with above adjustments

• what if the small color checker is not in focus?

  • Maybe we need to increase the F-number then, and increase the exposure time slightly. As well as the flash power

• what if the image is still dark at f/10?

Camera Settings Definitions

• Aperture and focus done manually on site

• Exposure setting configured in the .txt file

Resources

SVCam

• https://www.svs-vistek.com/en/industrial-cameras/svs-camera-detail.php?id=shr661CXGE

• 

Flash

• AD1200 Pro Battery Powered flash system

• Ring flash Head for AD1200 Pro

• High-Capacity battery for AD1200 Pro

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Lens

• Linos Inspect XL 60mm (link)

Color Checker Chart

• XRite ColorChecker calibration data sheet -