To reduce backscatter from suspended particles in the water I am considering mounting the lights on arms to get them further away from the camera and then angle them in. Has this been done? Also I am concerned about having enough cord length to do so. I am aware that this will effect the hydrodynamics of the ROV.
I mounted arms lengthwise along the top sides of my ROV. A servo mounted on the ROV pulls a cable which makes them swing out and forward. Spring return. I mounted 4 624 lumen LED lights to a square piece of polycarbonate. One square on the end of each arm. I coated the LED’s with epoxy resin to waterproof them, no case required. Two waterproof servos mounted on the ROV pull bicycle shift cables which run out along the arms to pan/tilt the LED squares as the camera inside the WTC pans and tilts. This insures the camera is never blinded. https://www.amazon.com/gp/product/B07678LQ57?pf_rd_p=183f5289-9dc0-416f-942e-e8f213ef368b&pf_rd_r=0EAMCA1SJ0ZZWW9EBRGA
My newest design is for each arm to be two-piece, and scissor-telescope out, like the first two sections of a bird’s wing. This way i can stop them partway and still have the lights pointing forward.
To reduce hydrodynamic drag, you might try building the arms with minimal cross-section. Less surface area means less drag. Try using carbon-fiber arrow shafts. Remember to sand then clean carbon-fiber with isopropyl alcohol before gluing so the glue will stick well.
…im mounting them on 12 kgf servos soon… so i can control together with cam tilt, or seperatly. mount the light Over the cam, you get less debris in the picture