Cateye Micro Halogen Headlights HL-500II vs. MC-200?

Discussion in 'Road Cycling' started by Steve Sr., Feb 19, 2006.

  1. Peter Cole wrote:
    > [email protected] wrote:
    > >
    > >
    > > It's not obvious to me that LEDs would be mounted significantly more
    > > accurately than a filament bulb.

    >
    > Incandescents have a fairly large filament, which makes them non-point
    > sources, giving hot spots in the beam....
    >
    > LEDs are much closer to a point source. The actual radiating surface is
    > tiny, usually a lens is built into the housing. White LEDs, like the
    > high power ones in the better bike lights use phosphors (like
    > fluorescents), so they have a somewhat larger radiating surface, but the
    > radiation pattern is uniform and the surface is still small relative to
    > incandescents.


    >From what I've seen, LEDs are not, practically speaking, a point

    source. Yes, deep inside the plastic housing, the emitting surface
    itself is small, but ISTM the optics of the plastic are such that the
    effective "source" is the plastic body. Certainly this is true with
    the common white LEDs, where the white light output is dependent on
    flourescing the compounds in the plastic. That plastic body is way
    bigger than a point!

    A typical halogen filament is a little wider (side to side) than a
    typical LED, but is much smaller in the vertical direction. ISTM that
    this would allow _more_ precise focusing, as long as the location of
    the filament is adequately controlled.

    Now I don't know if high output Luxeons are the same as other LEDs in
    this regard. I don't own any, yet. But I suspect they are.

    I notice that filament-based bike lights (and car headlights, etc.)
    frequently have very sharp, well-defined beam shapes, characteristic of
    very good optical control. Every LED-based light I've seen has lacked
    the sharp cutoffs. To me, this is evidence that the LED isn't as
    focusable.


    > When riding with lights, you pick out much surface detail by the shadows
    > cast. It isn't helpful when the light source casts its own shadows.


    The question is, what level of nonuniformity is a problem? I know of
    no evidence that any ordinary bike light has a level of nonuniformity
    that rises beyond the "personal preference" level. And personal
    preference is obviously a YMMV thing.

    - Frank Krygowski
     


  2. [email protected] wrote:
    <significant snippage>
    > I notice that filament-based bike lights (and car headlights, etc.)
    > frequently have very sharp, well-defined beam shapes, characteristic of
    > very good optical control. Every LED-based light I've seen has lacked
    > the sharp cutoffs. To me, this is evidence that the LED isn't as
    > focusable.
    >

    Frank -

    I have a bit of experience with good quality incandescent lighting both
    on cars and on bikes and I can't agree with your last sentence, though
    I'm allowing for misunderstanding on my part.

    For many years a decent lamp was characterized by a high quality
    parabolic reflector, a well positioned light source, and an optical
    lens to shape the beam to the required ground pattern. Off topic are
    the newest automotive lamps which employ complex reflectors for beam
    shaping and virtually no optical lens.

    I have limited experience with LED lighting - only the NiteHawk
    Emitter. That beam is quite well focused. Unfortunately, it is focused
    solely by the parabolic reflector, so it has a conical pattern. Perhaps
    the only LED lights you've had a chance to observe have been similar.

    I believe that if NiteHawk had seen fit to develop a nice lens for this
    light that it would be much more satisfactory for its intended purpose.
    NiteHawk made their name on MR based lighting, though, for which no one
    sees fit to incorporate lenses and which are universally crappy (though
    I find them useful off road).

    I do believe that one day we will see a well made LED light with a good
    reflector and optical lens. It will have a pattern that will be as good
    as Lumotec or BiSy and will run for several hours on 4 AA batteries.
    The light output will be astounding. At least I hope we will.

    And I may be clever enough to figure out how to run it off my Sanyo BB
    generator....

    Cheers,
    Tom
     
  3. Peter Cole

    Peter Cole Guest

    [email protected] wrote:
    > Peter Cole wrote:
    >
    >>[email protected] wrote:
    >>
    >>>
    >>>It's not obvious to me that LEDs would be mounted significantly more
    >>>accurately than a filament bulb.

    >>
    >>Incandescents have a fairly large filament, which makes them non-point
    >>sources, giving hot spots in the beam....
    >>
    >>LEDs are much closer to a point source. The actual radiating surface is
    >>tiny, usually a lens is built into the housing. White LEDs, like the
    >>high power ones in the better bike lights use phosphors (like
    >>fluorescents), so they have a somewhat larger radiating surface, but the
    >>radiation pattern is uniform and the surface is still small relative to
    >>incandescents.

    >
    >
    > From what I've seen, LEDs are not, practically speaking, a point
    > source. Yes, deep inside the plastic housing, the emitting surface
    > itself is small, but ISTM the optics of the plastic are such that the
    > effective "source" is the plastic body. Certainly this is true with
    > the common white LEDs, where the white light output is dependent on
    > flourescing the compounds in the plastic. That plastic body is way
    > bigger than a point!


    If you look at the documents at the Luxeon site, the lens diameter is
    spec'ed at 6mm. They don't give the die dimension, but from the
    photographs, it looks like <1mm. Their drawings show the die having a
    phosphor layer directly deposited on it, so the emitting surface is the
    same size as the die. The lens is partially collimating the source,
    giving a "Lambertian" beam pattern of ~120 degrees. The reflector in the
    NiteHawk housing further collimates to perhaps 10 degrees. The degree of
    possible collimation is proportional to the relative size of the source
    and the focusing elements -- bigger source, bigger elements (lens and/or
    reflector).

    > A typical halogen filament is a little wider (side to side) than a
    > typical LED, but is much smaller in the vertical direction. ISTM that
    > this would allow _more_ precise focusing, as long as the location of
    > the filament is adequately controlled.


    You're wrong about this, and it's easy to see from the uniformity of the
    beam.

    > I notice that filament-based bike lights (and car headlights, etc.)
    > frequently have very sharp, well-defined beam shapes, characteristic of
    > very good optical control. Every LED-based light I've seen has lacked
    > the sharp cutoffs. To me, this is evidence that the LED isn't as
    > focusable.


    I think you're confusing a couple of issues. You can mask any light
    source with aperture, but the cutoff light is wasted. You can shape a
    beam with lens elements (common with sealed beam units on cars), but
    these are not perfect lenses, and the filaments are relatively large, so
    you get a pretty uneven beam. In many applications quantity is more
    important than quality.


    >>When riding with lights, you pick out much surface detail by the shadows
    >>cast. It isn't helpful when the light source casts its own shadows.

    >
    > The question is, what level of nonuniformity is a problem? I know of
    > no evidence that any ordinary bike light has a level of nonuniformity
    > that rises beyond the "personal preference" level. And personal
    > preference is obviously a YMMV thing.


    The typical incandescent flashlight has terrible beam uniformity, many
    bike lights I've seen are almost as bad. I'm shining one of the old
    Cateye HL-500 (2-C battery) lights on the wall as I type, it has a
    reflector that's wider than tall (~2"x1") and has lens elements molded
    (vertically oriented cylindrical lenses to spread the beam sideways and
    a central circular lens to give a bright spot -- shifted slightly below
    axis to make the spot "bottom heavy") it's very uneven, although a
    somewhat useful shape. You can clearly see the projected image of the
    bulb top (dim center in bright spot). It's just not as effective as the
    LED light as far as uniform light beam goes. I find it harder to pick
    out shadowed objects when the beam has so many artifacts.
     
  4. Bill Baka

    Bill Baka Guest

    Peter Cole wrote:
    > Bill Baka wrote:
    >
    >> SMS wrote:
    >>
    >>> Bill Baka wrote:
    >>>
    >>>> It wasn't made up. I am an electronics engineer by trade and the
    >>>> quantum physics are there for anyone to look up if they can
    >>>> understand them. The only heat loss is in the resistors used to
    >>>> limit the current to the LEDs so they don't get too much current and
    >>>> burn out.
    >>>
    >>>
    >>>
    >>>
    >>> In fact, managing the heat generated by the high power LEDs is very
    >>> difficult, and Lumileds has whole papers dedicated to the subject.
    >>>
    >>> "http://www.lumileds.com/pdfs/AB05.pdf"

    >>
    >>
    >>
    >> The LEDs do get a little warm but not hot in the sense that anything
    >> is going to get hurt.
    >> Bill

    >
    >
    > The figure used for incandescent efficiency is around 5%. That means 95%
    > of the electrical energy becomes heat. LEDs of the kind used in bikes
    > lights are less than 2x as efficient, so perhaps 10% -- 90% of
    > electrical energy converted to heat. A 5W halogen will generate around
    > 4.5W of heat, a 5W LED 4W, only slightly less -- there are electrical
    > and optical losses which have nothing to do with quantum physics.


    I didn't claim it was perfect, but research is going nuts on solid state
    light sources and hot filaments are soon to be a thing of the past.
    The main driving factor right now is not bike lights but cell phone and
    play station lighting for maximum battery life. They are even getting
    into organic LEDs, or OLEDs, so a chemically fueled bioluminescence is
    not too far fetched in the near future.
    I am happy with my Cateye for now.
    Bill
     
  5. Bill Baka

    Bill Baka Guest

    Peter Cole wrote:
    <Big snip again>
    >
    > The typical incandescent flashlight has terrible beam uniformity, many
    > bike lights I've seen are almost as bad. I'm shining one of the old
    > Cateye HL-500 (2-C battery) lights on the wall as I type, it has a
    > reflector that's wider than tall (~2"x1") and has lens elements molded
    > (vertically oriented cylindrical lenses to spread the beam sideways and
    > a central circular lens to give a bright spot -- shifted slightly below
    > axis to make the spot "bottom heavy") it's very uneven, although a
    > somewhat useful shape. You can clearly see the projected image of the
    > bulb top (dim center in bright spot). It's just not as effective as the
    > LED light as far as uniform light beam goes. I find it harder to pick
    > out shadowed objects when the beam has so many artifacts.


    I have my Cateye Hl-EL300 with me and it has about a 10 degree beam
    spread. Each of the 5 LEDs has a lens in front of it and has about a 5
    degree beam per LED. Together they form a beam that is slightly more
    wide than high so I can see a bit off the side of the road. More than 15
    degrees there is no light on the road but enough for a person to see
    that the light is on. The LEDs are mounted on a circuit board and I can
    wiggle them a bit to fine tune the pattern and could probably make a 5
    degree spot light out of it, but why bother? I have it aimed to hit the
    road about 40 feet in front of me and the residual light makes the road
    almost under me visible so I have no complaints for a light that I only
    use at a maximum speed of 18 to 20 MPH, and usually just about 12 MPH.
    Why nit pick?
    Bill Baka
     
  6. Tim McNamara

    Tim McNamara Guest

    [email protected] writes:

    > [email protected] wrote:
    > <significant snippage>
    >> I notice that filament-based bike lights (and car headlights, etc.)
    >> frequently have very sharp, well-defined beam shapes,
    >> characteristic of very good optical control. Every LED-based light
    >> I've seen has lacked the sharp cutoffs. To me, this is evidence
    >> that the LED isn't as focusable.
    >>

    > Frank -
    >
    > I have a bit of experience with good quality incandescent lighting
    > both on cars and on bikes and I can't agree with your last sentence,
    > though I'm allowing for misunderstanding on my part.
    >
    > For many years a decent lamp was characterized by a high quality
    > parabolic reflector, a well positioned light source, and an optical
    > lens to shape the beam to the required ground pattern. Off topic are
    > the newest automotive lamps which employ complex reflectors for beam
    > shaping and virtually no optical lens.
    >
    > I have limited experience with LED lighting - only the NiteHawk
    > Emitter. That beam is quite well focused. Unfortunately, it is
    > focused solely by the parabolic reflector, so it has a conical
    > pattern. Perhaps the only LED lights you've had a chance to observe
    > have been similar.


    Good bicycle light optics provide a more or less rectangular beam
    pattern, brighter at the top and pretty sharply cut off. The result
    is an evenly lit patch of ground with good illumination at the far end
    of the beam. LED lights (that I have seen, which is a limited sample)
    just have a round beam of even brightness. That results in a puddle
    of light that is dimmer further away and brighter up close.

    What I like about LED beams is that there are no dark spots in the
    middle of the beam, which often seem to be present in halogen lights.
    There are some new generation LED generator lights made by companies
    that understand the optical needs of the bicyclist, so perhaps those
    have better beam patterns. I haven't seen 'em in person, though. An
    example is the Busch und Mueller DLumotec.
     
  7. Tim McNamara

    Tim McNamara Guest

    Bill Baka <[email protected]> writes:

    > Why nit pick?


    Oooohhhhh, dude, you *are* new to Usenet aren't you? ;-)
     
  8. Bill Baka

    Bill Baka Guest

    Tim McNamara wrote:
    > Bill Baka <[email protected]> writes:
    >
    >
    >>Why nit pick?

    >
    >
    > Oooohhhhh, dude, you *are* new to Usenet aren't you? ;-)


    Nah,
    I am an old timer, but there is always someone on any group that just
    HAS to try to prove he is an expert. I have been around since DOS when
    the Internet was a public unknown. Some people have very easy buttons to
    push and I can't resist.
    Bill
     
  9. On Thu, 23 Feb 2006 03:48:16 GMT, Bill Baka wrote:

    > I am an old timer, but there is always someone on any group that just
    > HAS to try to prove he is an expert.


    The sort of twit who's read just enough about quantum physics to
    claim that it gives LEDs close to 100% efficiency, for example.

    --
    Home page: http://members.westnet.com.au/mvw
     
  10. Sorni

    Sorni Guest

    Bill Baka wrote:

    > ...there is always someone on any group that just
    > HAS to try to prove he is an expert.


    BWAHAHAHAHAHAHAHAHAHAHAHA! OMG my sides hurt.

    That's sort of like Hillary talking about the Bush Admin's penchant for
    withholding info! Delicious irony and/or hypocrisy (take your pick)...

    Bill "don't ever change, Bullshittin' Bill" S.
     
  11. Bill Baka

    Bill Baka Guest

    Sorni wrote:
    > Bill Baka wrote:
    >
    >
    >>...there is always someone on any group that just
    >>HAS to try to prove he is an expert.

    >
    >
    > BWAHAHAHAHAHAHAHAHAHAHAHA! OMG my sides hurt.
    >
    > That's sort of like Hillary talking about the Bush Admin's penchant for
    > withholding info! Delicious irony and/or hypocrisy (take your pick)...
    >
    > Bill "don't ever change, Bullshittin' Bill" S.
    >
    >

    Here, digest this from one supplier.
    http://www.aopinc.net/cgi-bin/v04/dbv04/display.cgi?search=1&Color_Type=New White
    Bill
     
  12. Peter Cole

    Peter Cole Guest

    Bill Baka wrote:
    > Sorni wrote:
    >
    >> Bill Baka wrote:
    >>
    >>
    >>> ...there is always someone on any group that just
    >>> HAS to try to prove he is an expert.

    >>
    >>
    >>
    >> BWAHAHAHAHAHAHAHAHAHAHAHA! OMG my sides hurt.
    >>
    >> That's sort of like Hillary talking about the Bush Admin's penchant
    >> for withholding info! Delicious irony and/or hypocrisy (take your
    >> pick)...
    >>
    >> Bill "don't ever change, Bullshittin' Bill" S.
    >>
    >>

    > Here, digest this from one supplier.
    > http://www.aopinc.net/cgi-bin/v04/dbv04/display.cgi?search=1&Color_Type=New White
    >
    > Bill


    Those are dinky little ones. That supplier does make 1, 3 & 5W LED like
    the Luxeons. They claim a "no phosphor" process, combining RGB LEDs
    rather than pumping a yellow phosphor with a blue LED like the Luxeons.
    Looking at the data sheet, they're claiming 32lumen/W in the 1W size,
    fairly typical for LEDs in that power these days. More efficient than
    overdriven halogen (~20 lumen/W), but not hugely so. Still only around
    10% of the electrical power coming out as light. The rest is heat, just
    like a regular bulb. The difference is that LEDs don't radiate that heat
    in their beam, just from the package.
     
  13. Rich

    Rich Guest

  14. Sorni

    Sorni Guest

    Rich wrote:
    > Bill Baka wrote:
    >
    >> Here, digest this from one supplier.
    >> http://www.aopinc.net/cgi-bin/v04/dbv04/display.cgi?search=1&Color_Type=New White

    >
    > Holy crap! Bullshit'n Bill actually tried backing up his claims with
    > a link (albiet unsuccessfully)! Maybe you can teach an old dog new
    > tricks.


    But it's not CATEYE's website, which is what he told someone to check out to
    back up his...(you know it's coming)...BULLSHIT!

    He funny. Still.

    BS
     
  15. Bill Baka

    Bill Baka Guest

    Rich wrote:
    > Bill Baka wrote:
    >
    >> Here, digest this from one supplier.
    >> http://www.aopinc.net/cgi-bin/v04/dbv04/display.cgi?search=1&Color_Type=New White

    >
    >
    >
    > Holy crap! Bullshit'n Bill actually tried backing up his claims with a
    > link (albiet unsuccessfully)! Maybe you can teach an old dog new tricks.
    >
    > Rich


    Did you read ALL the PDFs? The intent is to convert as much electricity
    as possible directly to light but there is thermal loss because of any
    material's resistance to electric current. I doubt that there ever will
    be 100% efficient conversion, but glowing wire lights are definitely not
    the way of the future. High pressure Sodium or Mercury vapor lights are
    really bright but the electronics would price them out of bicycle range
    anyway. They also generate a lot of heat, hence the quartz tube inside a
    protective glass tube. Besides, who wants a million candlepower for one
    minute before his batteries go dead?
    The LED lights work for me since I hate having to charge batteries all
    the time.
    Now DROP it.
    Bill
     
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