Converting/replacing Lumen lights with red lights?

Blue Robotics Products Lights
1

Hi,

Our marine lab has a BR ROV. We’d like to use it for observing fish at depth (100ish m) where any normal light is going to be disruptive. Is it possible/practical to replace or modify the standard Lumen lights with red ones? Is it practical to pull the front off them and put in a red filter?

Any suggestions much appreciated!
Thanks
Dean

2

Hi @Dean.C,

Cool! Sounds like an interesting application :slight_smile:

I can think of a few different approaches for this, which have different levels of difficulty:

  1. Use an existing red light instead of our Lumens
    • easy to hard difficulty, depending on approach
    • may have trouble with finding ones that are water-proof and bright enough
    • if you don’t need much light then it may be possible to wire up some of our red subsea LED indicators, or alternatively some standard red LEDs fitted to the inside of the enclosure dome
      • control of several LEDs wired in parallel could be done by ArduSub’s relay (on/off) or servo/lights (gradual) joystick controls, but for power reasons the signal would likely need to go via an electronic switch with power supplied directly from the battery
  2. Add a red filter to existing Lumen lights
    • should be reasonably easy
    • main concerns here would be
      • making sure the front O-ring is clean and properly lubricated before re-sealing
      • making sure not to overtighten the lens screws (concentrated stress can crack the lens)
      • making sure the filter doesn’t melt
  3. Replace the LED in a Lumen with an equivalent red one
    • Some effort involved - difficulty depends on prior experience with PCB dis/assembly
    • I don’t know of compatible ones, but they may exist (I haven’t tried looking)
    • This would require desoldering the existing LED, and soldering on a new one, and could fail to work and just end up with a broken Lumen
3

Hi Dean,

We had the same problem for observing fish at depth, so we made a 3d printed housing for this led 7x OSRAM SSL 80 hyper red on round PCB - Oslon SSL 80 LHCP7P-2T3T (3T) (led-tech.de) and used the same cable and connectors from the Lumen lights. Everything was potted with epoxy and works fine.

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1 Like
4

Thanks Eliot, all good information. I’m a bit worried about adding the filter for both the reasons you mentioned. I was wondering whether it would be worth getting a disc of transparent red acrylic and 3D printing something that would hold it over the front of the light.

On a different but related topic, have you got any idea if the standard camera has an M12 x 0.5 thread holding the lens the same as most CCTV cameras?

@lbentes
That looks like a really neat job! How did it perform at depth?

5

I don’t see any issues with that, assuming you’re able to block light leakage out from the sides without creating a pressure barrier that the water might break through instead of flowing in freely. I suppose you could just as easily wrap some cellophane over the front or something (instead of needing an acrylic disk), which would be a cheaper solution, albeit one that’s less robust to scratches, and may develop wrinkles and stretches.

Yes - that’s confirmed in the Technical Details section on our Low-Light HD USB Camera product page :slight_smile:

6

Hi Dean, right now we are just using it in tanks and very shallow as baited cameras, soon will go to around 100m.