Frame Quadrat

About: Paul Illsley

50cm X 50cm Frame Quadrat
(with GoPro Hero10 Black Camera)

50cm X 50cm frame quadrat with 50cm leg tubes

Parts List (3/4 inch PVC rigid conduit):

    GoPro Hero 10 camera with underwater housing and tripod mount
    1/4-20 threaded bolt to attach the tripod mount to the upper frame (1)
    90 degree elbows (8)
    T adaptors (6)
    5cm top tubes (6)
    12.5cm top tube (1) with a 1/4 inch hole drilled 4.3cm from one end for the tripod mount
    50cm bottom tube (1)
    23.7cm bottom tubes (6)
    50cm or 32cm leg tubes (3)
    Rubber washers for tripod mount (2)
    Zip Ties or Stainless Steel Tent Pole / Kayak Paddle Spring Snap Clips (at least 34 clips)
    Epoxy or another type of glue (optional)
    Drill with a 1/4 inch drill bit

GoPro Hero 10 camera in GoPro underwater housing with camera tripod mount attached

IMPORTANT: I found that adding a rubber gasket (or rubber washer) between the tripod mount and the tube helps to keep the camera secure.

I decided to go with a three-leg design because it was easier to mount the camera on the top plate assembly and it allows easy access to the study area in case you need to do so. I could have gone with a four-leg design but the 3/4 inch PVC conduit offers good rigidity and it seemed more than adequate for this application.

This design allows for the use of different cameras (not GoPro) by varying the location of the tripod mounting hole and the length of the two tubes leading to the camera mounting tube (so the lens can be centered in the top frame).

Components connected with Zip Ties.

You can drill small holes through the connection areas and use zip ties to secure the setup so it will not come apart when in use. These holes will also help release trapped air inside the tubing and allow for water drainage after use. I suggest you add thick tape over the trimmed zip ties so the user does not get injured from any sharp edges on the trimmed ends of the ties. The tube extends 2 cm inside the connector so if you drill your holes 1 cm from the edge of the connector you will be good. I used the same 1/4 inch drill bit for these holes and placed 2 zip ties in each hole. Or you could simply glue everything together and leave it permanently assembled.

Components connected with Tent Pole or Kayak Paddle Spring Snap Clips.

If you want a quick method of assembling your quadrat in the field, you can use stainless steel tent pole / kayak paddle spring snap clips. These work great and make a smooth connection surface. Make sure you mark each connection point with a unique identifier so you will be able to place the correct tube in the matching connector. This will ensure all the holes line up.

You will want to drill a few holes around the frame to allow air to escape and water to drain.

When using the waterproof housing you will probably want to place anti-fog inserts inside the housing along with the camera to lessen the chance of condensation forming inside when it is submerged. This is often a problem in humid climates or when the atmosphere is relatively damp. When the air inside the housing comes in contact with the housing (which is being cooled by the surrounding water), condensation can form on the lens area which will show up in your images.

Image using 50cm legs and the “Narrow” photo mode on the GoPro Hero10 Black
(distortion is corrected in the camera before the image is saved)
Images can only be saved as .jpg files in this mode.

Image recorded underwater with 50cm leg length (no distortion correction applied)
(GoPro Hero10 Black, RAW mode)

Painting your quadrat frame matte black (nonreflective) will help decrease the reflectance “glow” from the frame in murky, dark or sediment filled water.

50cm X 50cm frame quadrat with 32cm legs

GoPro cameras have a pre-focused lens and are not really designed for recording images at this close distance. These images will not be as sharp as ones recorded with a more traditional camera but they could be useable for many applications.

Image recorded above water with 32cm leg length (no distortion correction applied)
(GoPro Hero10 Black, RAW image setting)

The same image after lens distortion has been corrected using Adobe Camera Raw (Photoshop)
(GoPro Hero10 Black, RAW image setting)

Distortion correction tool in Adobe Camera Raw (Photoshop) software
(default settings for a GoPro Hero10 Black model)

Lens cap to protect the front lens port on the GoPro underwater housing for the Hero 9, 10, 11 and 12 Black cameras.
Here’s the STL file if you want to 3D print one for your housing: GoPro_10_Housing_Lens_Cap.stl

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