Candlepower -- a useful light output measure? Cateye LD1100 v. LD270compared.

Yesterday my Cateye TL-LD1100 was incapacitated when some fat bitch
carelessly or maliciously banged my bike with her car door at the
supermarket.

Fortunately I have a spare rear flasher, Cateye's TL-LD270, which I
promptly fitted.

The 270 is a tiny light compared to the 1100 which, by modern
standards at least, is a biggish light thought not truly a fistful.

From a medium distance, 30 or 40 paces, far enough at traffic speeds
for a driver to notice and react and slow, the 270 doesn't even in
daylight subjectively seem all that much less bright than the 1100
(which is bright enough for use in bright sunshine), though clearly
the bigger 1100 attracts attention at greater ranges than the 270 can
manage.

But here's the kicker. The 270 is said by Cateye to be rated at 4cd or
candlepower whereas the 1100 is rated at 100 candlepower.

Even keeping in mind that this is a subjective test, and that
perceived light does not answer to a linear rule, I must say that cd
or candlepower seems to me a rating so unilluminating (intended pun)
as to be useless for any practical purpose of consumer comparison.

****
For those in the market for a flasher: Buy the bigger LD1100; it is
only a few dollars more at the discounters and it is truly a daylight
warning lamp. If you're a hyper-weight weenie, or have only a tiny
space available, the LD270 appears to be a very good light; it is
unfair to any light to compare it to the exceptional LD1100.

The discounted price difference of a few dollars isn't even all
accounted for by the light output: the 270 has only flashing and
steady programmes, whereas the 1100 has a steady and three flashing
programmes separately controlled on each row of five powerful LEDs.
The 270, incidentally, attaches tidily with Cateye's latest bracket,
intended for seatpost attachment, to a 10mm pannier rack strut, which
the older bracket on the 1100 won't do; my 1100 was tiewrapped to the
racktop bag permanently on the bike.

Besides the amount of light produced, and the attachment comparison,
the LD1100 has the huge advantage of two LEDS on each side pointing
perpendicularly to the side of the bike, and optics that ensure for
practical purposes all round visibility. Day or night, a driver would
have to be blind not to see the LD1100.

*******

While I'm glad to have the TL-LD270 for interim use, and it seems to
me a much, much better rear light than comparison of the ratings might
indicate, I think I'll order another TL-LD1100 and be certain of being
seen.

Andre Jute
Visit Andre's books at
http://www.audio-talk.co.uk/fiultra/THE%20WRITER'S%20HOUSE.html

I thought that lumens were the correct unit for measuring the brightness
of things like tail lamps?

On 3/25/2009 3:32 PM Andre Jute wrote:

Yesterday my Cateye TL-LD1100 was incapacitated when some fat bitch
carelessly or maliciously banged my bike with her car door at the
supermarket.

Fortunately I have a spare rear flasher, Cateye's TL-LD270, which I
promptly fitted.

The 270 is a tiny light compared to the 1100 which, by modern
standards at least, is a biggish light thought not truly a fistful.

From a medium distance, 30 or 40 paces, far enough at traffic speeds
for a driver to notice and react and slow, the 270 doesn't even in
daylight subjectively seem all that much less bright than the 1100
(which is bright enough for use in bright sunshine), though clearly
the bigger 1100 attracts attention at greater ranges than the 270 can
manage.

But here's the kicker. The 270 is said by Cateye to be rated at 4cd or
candlepower whereas the 1100 is rated at 100 candlepower.

Even keeping in mind that this is a subjective test, and that
perceived light does not answer to a linear rule, I must say that cd
or candlepower seems to me a rating so unilluminating (intended pun)
as to be useless for any practical purpose of consumer comparison.

****
For those in the market for a flasher: Buy the bigger LD1100; it is
only a few dollars more at the discounters and it is truly a daylight
warning lamp. If you're a hyper-weight weenie, or have only a tiny
space available, the LD270 appears to be a very good light; it is
unfair to any light to compare it to the exceptional LD1100.

The discounted price difference of a few dollars isn't even all
accounted for by the light output: the 270 has only flashing and
steady programmes, whereas the 1100 has a steady and three flashing
programmes separately controlled on each row of five powerful LEDs.
The 270, incidentally, attaches tidily with Cateye's latest bracket,
intended for seatpost attachment, to a 10mm pannier rack strut, which
the older bracket on the 1100 won't do; my 1100 was tiewrapped to the
racktop bag permanently on the bike.

Besides the amount of light produced, and the attachment comparison,
the LD1100 has the huge advantage of two LEDS on each side pointing
perpendicularly to the side of the bike, and optics that ensure for
practical purposes all round visibility. Day or night, a driver would
have to be blind not to see the LD1100.

*******

While I'm glad to have the TL-LD270 for interim use, and it seems to
me a much, much better rear light than comparison of the ratings might
indicate, I think I'll order another TL-LD1100 and be certain of being
seen.

Andre Jute
Visit Andre's books at
http://www.audio-talk.co.uk/fiultra/THE%20WRITER'S%20HOUSE.html



--
Mike "Rocket J Squirrel"
Bend, Oregon

On 25 Mar, 23:17, Mike Rocket J Squirrel
wrote:
I thought that lumens were the correct unit for measuring the brightness
of things like tail lamps?


Yes. I believe the lumen figure to be taken as the light falling on a
point away from the lamp whilst a candela figure is that which is
emitted by the lamp emmiter(bulb or LEDs). This would make any
candela figure innapropriate. The lumen figure would also require a
standard test (set distace, within a set horizontal and vertical
deviation, stadard colour, within a lumen range).

TJ

On Mar 27, 8:37*pm, Nick L Plate wrote:

Yes. *I believe the lumen figure to be taken as the light falling on a
point away from the lamp whilst a candela figure is that which is
emitted by the lamp emmiter(bulb or LEDs). *This would make any
candela figure innapropriate. *The lumen figure would also require a
standard test (set distace, within a set horizontal and vertical
deviation, stadard colour, within a lumen range).

No, lumens measure the total light output for a light source.

http://www.ledtronics.com/TechNotes/...tes.aspx?id=13 has a pretty
good explanation for these confusing units of measurement.
http://www.westsidesystems.com/rays.html has another one.

- Frank Krygowski

On 28 Mar, 02:08, Frank Krygowski wrote:
On Mar 27, 8:37*pm, Nick L Plate wrote:



Yes. *I believe the lumen figure to be taken as the light falling on a
point away from the lamp whilst a candela figure is that which is
emitted by the lamp emmiter(bulb or LEDs). *This would make any
candela figure innapropriate. *The lumen figure would also require a
standard test (set distace, within a set horizontal and vertical
deviation, stadard colour, within a lumen range).

No, lumens measure the total light output for a light source.

http://www.ledtronics.com/TechNotes/....aspx?id=13has a pretty
good explanation for these confusing units of measurement.http://www.westsidesystems.com/rays.htmlhas another one.


Dictionary check

lumen n a unit of luminuous flux - the light emitted in one second in
a solid angle of one steradian from a point that is a radiation source
of uniform intensity of one candela.

On Mar 27, 11:11*pm, Nick L Plate wrote:
On 28 Mar, 02:08, Frank Krygowski wrote:



On Mar 27, 8:37*pm, Nick L Plate wrote:

Yes. *I believe the lumen figure to be taken as the light falling on a
point away from the lamp whilst a candela figure is that which is
emitted by the lamp emmiter(bulb or LEDs). *This would make any
candela figure innapropriate. *The lumen figure would also require a
standard test (set distace, within a set horizontal and vertical
deviation, stadard colour, within a lumen range).

No, lumens measure the total light output for a light source.

http://www.ledtronics.com/TechNotes/...aspx?id=13hasa pretty
good explanation for these confusing units of measurement.http://www.westsidesystems.com/rays.htmlhasanother one.

*Dictionary check

lumen n *a unit of luminuous flux - the light emitted in one second in
a solid angle of one steradian from a point that is a radiation source
of uniform intensity of one candela.

Again, the units are confusing.

Perhaps the simplest way to understand what lumens measure is to
examine a light bulb package. The package of household bulbs I just
grabbed said "Total light output: 1600 lumens." That explains it
adequately.

Reflectors and lenses concentrate those lumens, affecting the number
of lumens per steradian. Projecting them onto surfaces affects the
number of lumens per square foot or per square meter. But the
fundamental amount of light is measured in lumens.

- Frank Krygowski

The Cateye TL-LD1100 rear light takes 2x AA batteries which cost
possibly two bucks for ten or a dozen and last 120 hours on flash -- I
used to replace them once a month just to be certain and then once
every two months and more recently was waiting for rechargeables to
run out but lost track of usage at about 60 hours with the lamp still
strong. In any event, battery usage is hardy a consideration in owning
the lamp. The initial price is, though; it is listed at 57 Euro, which
is pricey but in my opinion worth it; discounters sell it in the
middle thirties.

As I've reported before, after my LD1100 got trashed in the
supermarket parking lot by a fat cow with her car door, I started
using the TL-LD270 which came in the pack with my HL-EL320 front
flasher. The LD270 is a satisfactory rear light; if I didn't know
about the 1100 I would probably give it full marks, and even against
the 1100 it gets 4 out of 5, considering only light output and
visibility, both of which are better than the specs would seem to
indicate. The 270 costs only 20 Euro or so, less at the discounters.

But the price advantage of the 270 falls down flat, disastrously, when
one has to fit new batteries. It was, stupidly, designed to take Size
N batteries.

As we have seen, using rechargeable batteries in my 1100 is
essentially a costless procedure. How do you allocate a per hour
charge to a pair of batteries that cost say 2 Euro 50 cents, last for
120 hours per charge, and can be recharged 500-1000 times? Add
something for mains electricity for recharging? Depreciate the capital
cost of the fifteen buck battery charger? Calculate a global
environmental cost for disposing of the dead batteries and add a
"Kyoto loading" of a trillion or two? The whole affair has enough
zeroes after the decimal point to make my head hurt.

Cateye's TL-LD1100 taillight is therefore essentially costless to run,
after you've made the capital investment of lamp, rechargeable
batteries and charger.

But the two N type batteries (not even rechargeable) in the 270 cost 5
Euro between them at the supermarket and last 60 hours. At two hours
of use per day, just the difference between a brilliant battery
specification for the 1100 and a stupid stupid stupid battery
specification for the 270 will pay for a new 1100 at the discounters
in six or seven months.

Or, to put it another way: After six months of use, the exceptionally
competent but initially expensive 1100 will be a cheaper rear light
than the cheap and cheerful 270.

Ouch! Only the desperately short of funds should buy Cateye's TL-
LD270. And then only until they can afford a TL-LD1100, at which point
it would be cost-effective to throw out the LD270. You can't even do
some poor cyclist a favour by giving the 270 to him -- it'll keep him
poor forever paying for those Size N batteries.

Andre Jute
A simple lesson in comparative economics. Wonderful thing, education.

On Mar 25, 10:32*pm, Andre Jute wrote:
Yesterday my Cateye TL-LD1100 was incapacitated when some fat bitch
carelessly or maliciously banged my bike with her car door at the
supermarket.

Fortunately I have a spare rear flasher, Cateye's TL-LD270, which I
promptly fitted.

The 270 is a tiny light compared to the 1100 which, by modern
standards at least, is a biggish light thought not truly a fistful.

From a medium distance, 30 or 40 paces, far enough at traffic speeds
for a driver to notice and react and slow, the 270 doesn't even in
daylight subjectively seem all that much less bright than the 1100
(which is bright enough for use in bright sunshine), though clearly
the bigger 1100 attracts attention at greater ranges than the 270 can
manage.

But here's the kicker. The 270 is said by Cateye to be rated at 4cd or
candlepower whereas the 1100 is rated at 100 candlepower.

Even keeping in mind that this is a subjective test, and that
perceived light does not answer to a linear rule, I must say that cd
or candlepower seems to me a rating so unilluminating (intended pun)
as to be useless for any practical purpose of consumer comparison.

****
For those in the market for a flasher: Buy the bigger LD1100; it is
only a few dollars more at the discounters and it is truly a daylight
warning lamp. If you're a hyper-weight weenie, or have only a tiny
space available, the LD270 appears to be a very good light; it is
unfair to any light to compare it to the exceptional LD1100.

The discounted price difference of a few dollars isn't even all
accounted for by the light output: the 270 has only flashing and
steady programmes, whereas the 1100 has a steady and three flashing
programmes separately controlled on each row of five powerful LEDs.
The 270, incidentally, attaches tidily with Cateye's latest bracket,
intended for seatpost attachment, to a 10mm pannier rack strut, which
the older bracket on the 1100 won't do; my 1100 was tiewrapped to the
racktop bag permanently on the bike.

Besides the amount of light produced, and the attachment comparison,
the LD1100 has the huge advantage of two LEDS on each side pointing
perpendicularly to the side of the bike, and optics that ensure for
practical purposes all round visibility. Day or night, a driver would
have to be blind not to see the LD1100.

*******

While I'm glad to have the TL-LD270 for interim use, and it seems to
me a much, much better rear light than comparison of the ratings might
indicate, I think I'll order another TL-LD1100 and be certain of being
seen.

Andre Jute
*Visit Andre's books at
*http://www.audio-talk.co.uk/fiultra/THE%20WRITER'S%20HOUSE.html

On 29 Mar, 01:58, Andre Jute wrote:
The Cateye TL-LD1100 rear light takes 2x AA batteries which cost
possibly two bucks for ten or a dozen and last 120 hours on flash -- I
used to replace them once a month just to be certain and then once
every two months and more recently was waiting for rechargeables to
run out but lost track of usage at about 60 hours with the lamp still
strong. In any event, battery usage is hardy a consideration in owning
the lamp. The initial price is, though; it is listed at 57 Euro, which
is pricey but in my opinion worth it; discounters sell it in the
middle thirties.

As I've reported before, after my LD1100 got trashed in the
supermarket parking lot by a fat cow with her car door, I started
using the TL-LD270 which came in the pack with my HL-EL320 front
flasher. The LD270 is a satisfactory rear light; if I didn't know
about the 1100 I would probably give it full marks, and even against
the 1100 it gets 4 out of 5, considering only light output and
visibility, both of which are better than the specs would seem to
indicate. The 270 costs only 20 Euro or so, less at the discounters.

But the price advantage of the 270 falls down flat, disastrously, when
one has to fit new batteries. It was, stupidly, designed to take Size
N batteries.

As we have seen, using rechargeable batteries in my 1100 is
essentially a costless procedure. How do you allocate a per hour
charge to a pair of batteries that cost say 2 Euro 50 cents, last for
120 hours per charge, and can be recharged 500-1000 times? Add
something for mains electricity for recharging? Depreciate the capital
cost of the fifteen buck battery charger? Calculate a global
environmental cost for disposing of the dead batteries and add a
"Kyoto loading" of a trillion or two? The whole affair has enough
zeroes after the decimal point to make my head hurt.

Cateye's TL-LD1100 taillight is therefore essentially costless to run,
after you've made the capital investment of lamp, rechargeable
batteries and charger.

But the two N type batteries (not even rechargeable) in the 270 cost 5
Euro between them at the supermarket and last 60 hours. At two hours
of use per day, just the difference between a brilliant battery
specification for the 1100 and a stupid stupid stupid battery
specification for the 270 will pay for a new 1100 at the discounters
in six or seven months.

Or, to put it another way: After six months of use, the exceptionally
competent but initially expensive 1100 will be a cheaper rear light
than the cheap and cheerful 270.

Ouch! Only the desperately short of funds should buy Cateye's TL-
LD270. And then only until they can afford a TL-LD1100, at which point
it would be cost-effective to throw out the LD270. You can't even do
some poor cyclist a favour by giving the 270 to him -- it'll keep him
poor forever paying for those Size N batteries.

Andre Jute
A simple lesson in comparative economics. Wonderful thing, education.



So the fat cow paid for the broken lamp up front, did she?
Or have you not weighed in the probability of having the lamp broken/
stolen/malfunction ?
It's not so simple if you have no idea of the risk. Why not start
adding up the time you're saving by not having to recharge batteries?
The cost of common dry cell batteries is so low that unless you are
using rechargables with a low self drain, then overall you would be at
a disadvantage.

TJ

On Mar 28, 6:17*pm, Nick L Plate wrote:

So the fat cow paid for the broken lamp up front, did she?
Or have you not weighed in the probability of having the lamp broken/
stolen/malfunction ?
It's not so simple if you have no idea of the risk. *Why not start
adding up the time you're saving by not having to recharge batteries?
The cost of common dry cell batteries is so low that unless you are
using rechargables with a low self drain, then overall you would be at
a disadvantage.

The consideration of rechargable cells was an unnecessary complication
in the comparison. The extra time and trouble to recharge may well
not be worthwhile if the only application is for a rear blinking
light. But if other items that drain cells faster will also be using
the rechargable cells then the extra trouble to include the cells from
the blinky is pretty negligible.

But the primary point is that the use the widely available and
competitively priced AA cells has a benefit to the consumer compared
to items that use less common battery sizes. According to the specs
given, the AA cells in the LD1100 will last twice as long and cost
only about one tenth as much if disposable cells are used in both
cases. That ratio makes the AA cells almost free in comparison to the
N cells even if disposable cells are used.

"Peter Rathmann" wrote in message
...

But the primary point is that the use the widely available and
competitively priced AA cells has a benefit to the consumer compared
to items that use less common battery sizes. According to the specs
given, the AA cells in the LD1100 will last twice as long and cost
only about one tenth as much if disposable cells are used in both
cases. That ratio makes the AA cells almost free in comparison to the
N cells even if disposable cells are used.

When choosing battery equipment, I've always gone for stuff based on AA
rather than AAA, and mentioned this to Cateye at least once. N cells are
even worse than AAA - not sure quite what Cateye were thinking when they
specced those - sure, they may be small, but availability is pathetic
compared to AA/AAA.

(in case of confusion, this is actually agreeing with both Peter and Andre)