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High(er) end canister?

Discussion in 'Lights' started by Coldwaters, Oct 20, 2017.

  1. JohnnyC

    JohnnyC PADI Pro

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    I've never used variable focus on a primary and have never felt lacking. I have a couple HID's that allow you to focus them, but I literally never touch them except when I need to change the lamp and have to take them apart.
     
  2. Lorenzoid

    Lorenzoid idling in neutral buoyancy ScubaBoard Supporter

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    I'm not a cave diver (yet), but I have heard that from people before. I have never understood the "need" for variable focus. With HIDs, I could understand why they might include that feature: because it is so darn simple and cheap to include--just allow the user to move the reflector--they might as well include it. But with LED, adding something like a Fresnel lens is a big deal. Why? What kind of diver is driving the demand for variable focus?
     
  3. Berry Ke

    Berry Ke Angel Fish

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    Of course it might just be marketing but I understood it's useful to change between a tight beam for signaling and a wider beam for having a wider area to light up if you're looking around?
    And if it's not necessary to buy a variable focus what degree of beam is a good ("allround") beam?
     
  4. tbone1004

    tbone1004 Technical Instructor ScubaBoard Supporter

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    @Berry Ke I have used them before with an old HID, but it is not something I've ever felt a need to have. It is more important if you don't have a light with variable output as you can't turn it down if you are in high particulate, but if you have multiple light output options, it is not something I have ever felt the need to have. The cost of the variable focus is the massive increase in head size.
     
  5. Lorenzoid

    Lorenzoid idling in neutral buoyancy ScubaBoard Supporter

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    Sure, but what I was asking was to what kind of potential customer is the tradeoff of high cost worth it? Even with a variable-focus light at its narrowest beam setting, there is plenty of spillover/halo to "look around." It's not like a laser beam. I can imagine that it might be interesting every once in a while on a cave dive to widen the beam and take in the majestic view, but how many divers actually stop and do that? Enough to justify the significantly increased cost of including a variable-focus feature in an LED light?
     
  6. tbone1004

    tbone1004 Technical Instructor ScubaBoard Supporter

    # of Dives: I'm a Fish!
    Location: Greenville, South Carolina, United States
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    see article
    Beam Angle: Fact & Fiction

    see video and comparison sheet
    Beam Comparison

    the key is to have a wide enough corona to "see" what you need to see, with a tight enough hotspot that allows you to signal. The key to have the light be functional in low visibility is to be able to turn it down to a low setting in order to minimize the backscatter.
    HID's are single output and can't be changed so the variable focus was nice if you wanted a wider spill in normal conditions but needed to tighten it up so it didn't look like high-beams in the snow.
    Light Monkey has not had a multi-output light up until this most recent one but they are looking at the focusable as still being "stuck" in the HID paradigm which is why their light heads still look like a HID light head, and why even though they now have a piezo switch on the head, they still have a switch on the lid, etc.

    Variable focus is just not something you really need in a primary light. The primary light alone is more than good enough for gopro video, and if and when you need to go to more light for that, get a video light head. At least with the UWLD units, you can buy the head and stick it on the same canister and swap over as you need it when diving.
     

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