Are they A Good Thing for cheering up a kitchen through the winter, and
possibly having a beneficial effect on the symptoms of SAD? I'm having some
bother finding a 6' one locally but if they're worth having I'll continue
the search.

Si

Mungo "Two Sheds" Toadfoot wrote:
Are they A Good Thing for cheering up a kitchen through the winter,
and possibly having a beneficial effect on the symptoms of SAD? I'm
having some bother finding a 6' one locally but if they're worth
having I'll continue the search.

Si

And... is there any difference between 'normal' daylight tubes and 'full
spectrum' jobs?

In article ,
"Mungo \"Two Sheds\" Toadfoot" writes:
Are they A Good Thing for cheering up a kitchen through the winter, and

Definitely not. They have the most appalling effect on the colour
of food, and unless you lined the ceiling with loads of tubes to
get the lighting level up to that of midday sun, the colour will
look wrong.

possibly having a beneficial effect on the symptoms of SAD? I'm having some
bother finding a 6' one locally but if they're worth having I'll continue
the search.

SAD needs a bright light. There's no evidence colour makes a scrap
of difference, but the manufacturers of special lights like you to
think it does so you'll buy their very expensive replacement tubes.

One 6' tube mounted on the ceiling probably isn't anywhere near
enough to make any difference. If you want to make a SAD lamp, the
cheapest way is probably to buy a 4-tube modular ceiling luminare
designed to sit on a 600mm ceiling tile frame (either 600mm square
or 600x1200mm). They're dirt cheap from an electrical wholesaler
and often free from a skip. You can hang it on the wall like a
picture next to where you sit/work, like a sort of fake window.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 1 Oct, 10:07, "Mungo \"Two Sheds\" Toadfoot"
wrote:
Mungo "Two Sheds" Toadfoot wrote:

Are they A Good Thing for cheering up a kitchen through the winter,
and possibly having a beneficial effect on the symptoms of SAD? I'm
having some bother finding a 6' one locally but if they're worth
having I'll continue the search.

Si

And... is there any difference between 'normal' daylight tubes and 'full
spectrum' jobs?

added sci.engr.lighting as crosspost from uk.d.i.y

Probably several multiples of price.....

Full Spectrum is marketing mumbo, fluro by the very way it works has a
peak and trough spectral power distribution.
People like the dodgy Dr Ott sell all sorts of impressively packaged
"full spectrum" fluorescent lamps, if you really want full spectrum,
halogen has a continuous spectral output.

Daylight tubes are often just high colour temperature, which in an
internal kitchen might look very cold and as Andrew said can have poor
actual colour rendering. High colour rendering index lamp is really
more what you want, decent lamps made by big manufacturers aimed at
things like the print, textile and car refinishing business be more
appropriate.

Some research says colour does make a difference, been some research
on use of blue LED in resetting circadian rythmns in the elderley,
some research says intensity matters some that time and length of
exposure is most important, doesn`t seem to be a well understood
phenomenon.Offering opportunity for snake oil salesman to enter the
fray.

Adam

Andrew Gabriel wrote:
In article ,
"Mungo \"Two Sheds\" Toadfoot" writes:
Are they A Good Thing for cheering up a kitchen through the winter,
and

Definitely not. They have the most appalling effect on the colour
of food, and unless you lined the ceiling with loads of tubes to
get the lighting level up to that of midday sun, the colour will
look wrong.


Thanks Andrew, and Adam, for the advice. It was just a thought.

Si

"Adam Aglionby" wrote in message
...
On 1 Oct, 10:07, "Mungo \"Two Sheds\" Toadfoot"
wrote:
Mungo "Two Sheds" Toadfoot wrote:

Are they A Good Thing for cheering up a kitchen through the winter,
and possibly having a beneficial effect on the symptoms of SAD? I'm
having some bother finding a 6' one locally but if they're worth
having I'll continue the search.

Si

And... is there any difference between 'normal' daylight tubes and 'full
spectrum' jobs?

added sci.engr.lighting as crosspost from uk.d.i.y

Probably several multiples of price.....

Full Spectrum is marketing mumbo, fluro by the very way it works has a
peak and trough spectral power distribution.
People like the dodgy Dr Ott sell all sorts of impressively packaged
"full spectrum" fluorescent lamps, if you really want full spectrum,
halogen has a continuous spectral output.

Daylight tubes are often just high colour temperature, which in an
internal kitchen might look very cold and as Andrew said can have poor
actual colour rendering. High colour rendering index lamp is really
more what you want, decent lamps made by big manufacturers aimed at
things like the print, textile and car refinishing business be more
appropriate.

Some research says colour does make a difference, been some research
on use of blue LED in resetting circadian rythmns in the elderley,
some research says intensity matters some that time and length of
exposure is most important, doesn`t seem to be a well understood
phenomenon.Offering opportunity for snake oil salesman to enter the
fray.

Probably BS though as sunlight is not blue and its lack of sunlight that
causes SAD.
I would use warm white tubes myself and you need plenty of them, one tube is
not what you usually see to treat SAD, maybe five tubes or a 250w metal
halide lamp?

Adam

On 1 Oct, 10:11, (Andrew Gabriel) wrote:
In article ,
* * * * "Mungo \"Two Sheds\" Toadfoot" writes:

Are they A Good Thing for cheering up a kitchen through the winter, and

Definitely not. They have the most appalling effect on the colour
of food, and unless you lined the ceiling with loads of tubes to
get the lighting level up to that of midday sun, the colour will
look wrong.

possibly having a beneficial effect on the symptoms of SAD? I'm having some
bother finding a 6' one locally but if they're worth having I'll continue
the search.

SAD needs a bright light. There's no evidence colour makes a scrap
of difference, but the manufacturers of special lights like you to
think it does so you'll buy their very expensive replacement tubes.

(chop)
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

You need to tell Screwfix that as their spectral diagram in the Lamps
section shows SAD application as being beyond Daylight (16000k).
Snakeoil perhaps!!

Rob

On 1 Oct, 13:46, "dennis@home" wrote:
"Adam Aglionby" wrote in message

...



On 1 Oct, 10:07, "Mungo \"Two Sheds\" Toadfoot"
wrote:
Mungo "Two Sheds" Toadfoot wrote:

Are they A Good Thing for cheering up a kitchen through the winter,
and possibly having a beneficial effect on the symptoms of SAD? I'm
having some bother finding a 6' one locally but if they're worth
having I'll continue the search.

Si

And... is there any difference between 'normal' daylight tubes and 'full
spectrum' jobs?

added sci.engr.lighting as crosspost from uk.d.i.y

Probably several multiples of price.....

Full Spectrum is marketing mumbo, fluro by the very way it works has a
peak and trough spectral power distribution.
People like the dodgy Dr Ott sell all sorts of impressively packaged
"full spectrum" fluorescent lamps, if you really want full spectrum,
halogen has a continuous spectral output.

Daylight tubes are often just high colour temperature, which in an
internal kitchen might look very cold and as Andrew said can have poor
actual colour rendering. High colour rendering index lamp is really
more what you want, decent lamps made by big manufacturers aimed at
things like the print, textile and car refinishing business be more
appropriate.

Some research says colour does make a difference, been some research
on use of blue LED in resetting circadian rythmns in the elderley,
some research says intensity matters some that time and length of
exposure is most important, doesn`t seem to be a well understood
phenomenon.Offering opportunity for snake oil salesman to enter the
fray.

Probably BS though as sunlight is not blue and its lack of sunlight that
causes SAD.

Cant place the link offhand but it was serious research, blue LED
because its a very efficient generator of blue light aginst tungsten
or even fluro. Sunlight contains a lot of both visible and increasing
amounts invisible blueviolet radiation....

I would use warm white tubes myself and you need plenty of them, one tube is
not what you usually see to treat SAD, maybe five tubes or a 250w metal
halide lamp?

Intensity dosen`t seem to be universally accepted as the main
factor ,though personally think it is probably one factor.

Adam




Adam

"Andrew Gabriel" wrote in message
...
In article ,
"Mungo \"Two Sheds\" Toadfoot" writes:
Are they A Good Thing for cheering up a kitchen through the winter, and

Definitely not. They have the most appalling effect on the colour
of food, and unless you lined the ceiling with loads of tubes to
get the lighting level up to that of midday sun, the colour will
look wrong.

possibly having a beneficial effect on the symptoms of SAD? I'm having
some
bother finding a 6' one locally but if they're worth having I'll continue
the search.

SAD needs a bright light. There's no evidence colour makes a scrap
of difference, but the manufacturers of special lights like you to
think it does so you'll buy their very expensive replacement tubes.

One 6' tube mounted on the ceiling probably isn't anywhere near
enough to make any difference. If you want to make a SAD lamp, the
cheapest way is probably to buy a 4-tube modular ceiling luminare
designed to sit on a 600mm ceiling tile frame (either 600mm square
or 600x1200mm). They're dirt cheap from an electrical wholesaler
and often free from a skip. You can hang it on the wall like a
picture next to where you sit/work, like a sort of fake window.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

I used to know someone who had a 250W tungsten lamp in a white painted bog
not much bigger than a shoe box. Certainly woke me up!

I find that sufficient wake up brightness can be obtained with halogen
downlighters in a white painted bath/shower room. Add the reviving
influence of splashing water to the brilliance of the lamps and you should
come out feeling a whole lot better. [One proviso is to make sure the
transformers on the downlighters are able to take any wattage that is likely
to be plugged into them. The ones that were fitted in our kitchen were only
meant for 20W lamps, something that the fitter failed to mention, resulting
in some interesting on and off cycling of the lamps as they were gradually
replaced with 30W ones without realising.]

S

On 1 Oct, 09:46, "Mungo \"Two Sheds\" Toadfoot"
wrote:
Are they A Good Thing for cheering up a kitchen through the winter, and
possibly having a beneficial effect on the symptoms of SAD? I'm having some
bother finding a 6' one locally but if they're worth having I'll continue
the search.

Si

I am trialling a CFL daylight bulb in the bathroom, a bedroom and
dining room at the moment. They are all nice and bright - 150w
equivalent.

In the dining room, the light is OK in the day as it gives a bit of a
boost to daylight which is coming through the patio doors. But at
night it looks plain odd. Its too white, looks cold, and visually is
less preferable to the warmer CFLs in an adjacent room or the tungsten
spots in the kitchen. It does not promote a feeling of well-being at
night- just a feeling of unnaturalness.

In the bedroom, again it looks unnatural, but is a better light for
getting dressed and for mrs dg putting the make-up on. Its a shock
when the light is put on on during the night after darkness or if
waking up when its dark. It's not as calming as some warm low wattage
CFLs which we have in bedside lamps.

Its not a nice light to wake up.

In the bathroom, its a nice useful light. So this one will probably
stay and the others will be removed.

Full spectrum bulbs are just too subjective - as are all colour
temperatures really.

What exactly is colour accuracy and how is it needed at home? Its a
bit irrelevant

If you are doing photography, or need accurate colour rendition for
some commercial application, then fine, but at home, at night IMO, a
warm yellow is the most "natural"

dg

dg wrote:
On 1 Oct, 09:46, "Mungo \"Two Sheds\" Toadfoot"
wrote:
Are they A Good Thing for cheering up a kitchen through the winter, and
possibly having a beneficial effect on the symptoms of SAD? I'm having some
bother finding a 6' one locally but if they're worth having I'll continue
the search.

Si

I am trialling a CFL daylight bulb in the bathroom, a bedroom and
dining room at the moment. They are all nice and bright - 150w
equivalent.

In the dining room, the light is OK in the day as it gives a bit of a
boost to daylight which is coming through the patio doors. But at
night it looks plain odd. Its too white, looks cold, and visually is
less preferable to the warmer CFLs in an adjacent room or the tungsten
spots in the kitchen. It does not promote a feeling of well-being at
night- just a feeling of unnaturalness.

In the bedroom, again it looks unnatural, but is a better light for
getting dressed and for mrs dg putting the make-up on. Its a shock
when the light is put on on during the night after darkness or if
waking up when its dark. It's not as calming as some warm low wattage
CFLs which we have in bedside lamps.

Its not a nice light to wake up.

In the bathroom, its a nice useful light. So this one will probably
stay and the others will be removed.

Full spectrum bulbs are just too subjective - as are all colour
temperatures really.

What exactly is colour accuracy and how is it needed at home? Its a
bit irrelevant

If you are doing photography, or need accurate colour rendition for
some commercial application, then fine, but at home, at night IMO, a
warm yellow is the most "natural"

dg

Sorry - I feel that the 2700K CFLs are truly ghastly for use in the
living room in the evening! Even standard tungstens are a bit too
yellow. Not certain what temperature ours are, 4000K I think, and they
are fine.

Certainly anyone looking from outside might think it cold, but we are
quite happy. And warm. :-)

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

Mungo "Two Sheds" Toadfoot wrote:
Are they A Good Thing for cheering up a kitchen through the winter, and
possibly having a beneficial effect on the symptoms of SAD? I'm having some
bother finding a 6' one locally but if they're worth having I'll continue
the search.

Si


In line with the other thread, we have in our kitchen some of the 3500K
triphosphor under-cupboard low profile lights (from TLC). The colour
really is very acceptable. The use of multiple sources (rather than a
single 6 footer) reduces the shodow-casting.

If they could be used, I'd expect you to find them OK.

(PS SAD has all sorts of interesting connections with the thyroid. But
I'd better stop there. :-) )

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

Rod wrote:

(PS SAD has all sorts of interesting connections with the thyroid.
But I'd better stop there. :-) )

I'm all ears. Email works if you faff with it.

Si

"Rod" wrote in message
...
Mungo "Two Sheds" Toadfoot wrote:
Are they A Good Thing for cheering up a kitchen through the winter, and
possibly having a beneficial effect on the symptoms of SAD? I'm having
some bother finding a 6' one locally but if they're worth having I'll
continue the search.

Si
In line with the other thread, we have in our kitchen some of the 3500K
triphosphor under-cupboard low profile lights (from TLC). The colour
really is very acceptable. The use of multiple sources (rather than a
single 6 footer) reduces the shodow-casting.

If they could be used, I'd expect you to find them OK.

Yep, these are very good, and I even keep a 20W one as a handy portable
light. Only problems I've had is with the ballast failing and then when you
try to link in a replacement you find they change the end connectors every
year so you always have to cut them off and use an ordinary connector block.
Grrr. Still, the spare ends come in handy when you want a longer flex for
your old fm radio - or one in every room...

S

In article ,
robgraham writes:
On 1 Oct, 10:11, (Andrew Gabriel) wrote:
In article ,
* * * * "Mungo \"Two Sheds\" Toadfoot" writes:

Are they A Good Thing for cheering up a kitchen through the winter, and

Definitely not. They have the most appalling effect on the colour
of food, and unless you lined the ceiling with loads of tubes to
get the lighting level up to that of midday sun, the colour will
look wrong.

possibly having a beneficial effect on the symptoms of SAD? I'm having some
bother finding a 6' one locally but if they're worth having I'll continue
the search.

SAD needs a bright light. There's no evidence colour makes a scrap
of difference, but the manufacturers of special lights like you to
think it does so you'll buy their very expensive replacement tubes.

You need to tell Screwfix that as their spectral diagram in the Lamps
section shows SAD application as being beyond Daylight (16000k).
Snakeoil perhaps!!

Yes.

As I said in another thread, daylight is actually quite complex.
Although it measures 5400K, because the red and blue components
are split up in the atmosphere (red mainly coming direct from the
sun, and blue scattered and coming from all over the sky), a few
clouds can radically change it. A cloud blocking direct sunlight
can push the colour temperature very high (probably close to
your 16000k). When you look at objects illuminated by daylight,
you'll see a very different colour temperature depending if the
object is in direct sunlight (with red components) or in shadow
(so only blue components). For anything other than a horizontal
surface under a clear sky, an object illuminated by sunlight will
never actually see the 5400K -- it will either be higher or lower
depending on precise circumstances.

I have a 20,000K metal halide lamp. It's fun for lighting up the
garden at night at Christmas if it's covered in snow, but quite
useless for anything else (except possibly lighting corals and
tropical fish which is what it's designed for). However, you
can't run it indoors for longer than a few minutes, as although
it has an outer glass bulb and an explosion-proof luminare (as
required by all MH lamps), it still generates too much ozone
(too much UV leaks through the outer glass bulb, although not
out of the luminare). Incidently, This colour temperature,
lacking severely in reds, makes people's skintone look very
sick ;-)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

"Adam Aglionby" wrote in message
...
On 1 Oct, 13:46, "dennis@home" wrote:
"Adam Aglionby" wrote in message

...



On 1 Oct, 10:07, "Mungo \"Two Sheds\" Toadfoot"
wrote:
Mungo "Two Sheds" Toadfoot wrote:

Are they A Good Thing for cheering up a kitchen through the winter,
and possibly having a beneficial effect on the symptoms of SAD? I'm
having some bother finding a 6' one locally but if they're worth
having I'll continue the search.

Si

And... is there any difference between 'normal' daylight tubes and
'full
spectrum' jobs?

added sci.engr.lighting as crosspost from uk.d.i.y

Probably several multiples of price.....

Full Spectrum is marketing mumbo, fluro by the very way it works has a
peak and trough spectral power distribution.
People like the dodgy Dr Ott sell all sorts of impressively packaged
"full spectrum" fluorescent lamps, if you really want full spectrum,
halogen has a continuous spectral output.

Daylight tubes are often just high colour temperature, which in an
internal kitchen might look very cold and as Andrew said can have poor
actual colour rendering. High colour rendering index lamp is really
more what you want, decent lamps made by big manufacturers aimed at
things like the print, textile and car refinishing business be more
appropriate.

Some research says colour does make a difference, been some research
on use of blue LED in resetting circadian rythmns in the elderley,
some research says intensity matters some that time and length of
exposure is most important, doesn`t seem to be a well understood
phenomenon.Offering opportunity for snake oil salesman to enter the
fray.

Probably BS though as sunlight is not blue and its lack of sunlight that
causes SAD.

Cant place the link offhand but it was serious research, blue LED
because its a very efficient generator of blue light aginst tungsten
or even fluro. Sunlight contains a lot of both visible and increasing
amounts invisible blueviolet radiation....

I would use warm white tubes myself and you need plenty of them, one tube
is
not what you usually see to treat SAD, maybe five tubes or a 250w metal
halide lamp?

Intensity dosen`t seem to be universally accepted as the main
factor ,though personally think it is probably one factor.

Adam




Adam

Right. It's intensity x time = Dose Timing or when the light is provided
counts as well. Morning light is best. The spectral sensitivity curve peaks
in the blue, but it's a broad curve like the other human spectral
sensitivity curves, so any broad band white light will do. A 15-20 minute
walk outdoors even on a bright cloudy day will do it as will gazing out a
daylighted window for a similar time. It takes a substantial amount of
electric lighting to equal that dose level. Spectrum counts for very
little. Several articles and technical papers at:
http://www.lrc.rpi.edu/programs/lightHealth/index.asp

Terry McGowan

In ,
Adam Aglionby wrote:

On 1 Oct, 10:07, "Mungo \"Two Sheds\" Toadfoot"
wrote:
Mungo "Two Sheds" Toadfoot wrote:

Are they A Good Thing for cheering up a kitchen through the winter,
and possibly having a beneficial effect on the symptoms of SAD? I'm
having some bother finding a 6' one locally but if they're worth
having I'll continue the search.

Si

And... is there any difference between 'normal' daylight tubes and 'full
spectrum' jobs?

added sci.engr.lighting as crosspost from uk.d.i.y

Probably several multiples of price.....

Full Spectrum is marketing mumbo, fluro by the very way it works has a
peak and trough spectral power distribution.
People like the dodgy Dr Ott sell all sorts of impressively packaged
"full spectrum" fluorescent lamps, if you really want full spectrum,
halogen has a continuous spectral output.

Daylight tubes are often just high colour temperature, which in an
internal kitchen might look very cold and as Andrew said can have poor
actual colour rendering. High colour rendering index lamp is really
more what you want, decent lamps made by big manufacturers aimed at
things like the print, textile and car refinishing business be more
appropriate.

Some research says colour does make a difference, been some research
on use of blue LED in resetting circadian rythmns in the elderley,
some research says intensity matters some that time and length of
exposure is most important, doesn`t seem to be a well understood
phenomenon.Offering opportunity for snake oil salesman to enter the
fray.

It appears to me that exposure time and time-of-day and brightness
matter more than anything.
I have heard of beneficiel effect of certain colors (more blue or more
green), and hypothesis of a "cirtopic sensor" with a spectral response
peaking in the greenish blue.
Google on "cirtopic response" brings up 4 links (23 without omitting
very similar results), mentioning peak wavelength anywhere from 465 to 490
nm. With the small number of hits, I give fair chance that cirtopic
response may not be for real.

If cirtopic response does exist, ordinary halophosphor high color temp.
fluorescents such as "daylight" probably hits that better than any other
white light source - though high color temp. triphosphor has a minor but
slightly narrow band that *may* hit the cirtopic peak square-on. I have
no idea if cirtopic response is narrowband, or maybe as wideband as
scotopic response (in which case having high CCT, high s/p ratio and high
luminous output probably help more than any spectral details).

My experience is that 6500K fluorescents appear stark and often create a
"dreary" atmosphere unless illumination level gets to some extreme that is
typical of daylight, or at least a brighter degree of overcast - something
like 15,000-20,000 lux.

Personally, I like triphosphor fluorescents with CRI in the low-mid
80's. The color distortions are not in the direction of making colors
darker or duller, while non-triphosphor fluorescents do tend to make
colors (especially reds) darker and duller. I think it helps to have
colors brighter and more vivid for lighting to have beneficial mental
effect.
Having "full spectrum"/"broad spectrum" fluorescents with CRI around 90
or in the low 90's instead of 80's-CRI triphosphor goes back to darkening
and dulling colored objects although only slightly, and also has
significantly lower light output.

- Don Klipstein )

Was it from Flinders University. I remember seeing a story about the blue
LED glasses awhile ago on TV. Found this link:

https://socsci.flinders.edu.au/psyc/research/sleep/

The page includes the following:

___
Circadian rhythm phase shifting with the use of small light sources
Bright light stimulation has the capacity to shift the timing of circadian
(24-hour) rhythms of humans (the body clock). Sunlight or specially
constructed bright light boxes generating up to 3,000 lux of light at the
eyes can shift the timing of circadian rhythms to a later or earlier time
dependent on the timing of the light exposure. This phenomenon can be used
therapeutically to treat certain types of insomnia, jet lag, shift work
fatigue, and winter depression. However, these light sources are often not
available and have disadvantages of non portability and inconvenience which
reduce patient compliance and therapeutic effect. To overcome these
disadvantages we have developed small light emitting diodes (Leds) as an
effective light source. Although their total light output is minuscule
compared to the sun or light boxes, placed close to the eyes they can
provide up to 3,000 lux of light intensity. The first studies have found
significant melatonin suppression and phase delay during and following LED
light stimulation respectively but only with certain LED colours. The
studies have found the most effective LED colours to use for circadian
rhythm re-timing are in the blue and blue/green end of the coloured
spectrum. This research has led to the commercial development of blue LED
glasses for the application of bright light therapy, for sleep difficulties
caused by these body clock disorders.
Funding support:

Flinders Technologies, 1999-2000.

Principle Investigators:

Leon C. Lack, Prof., Helen R. Wright, PhD.

Publications:

Lack, L., Wright, H., Gibbon, S., Kemp, K. (2005). The treatment of
early-morning awakening insomnia with two evenings of bright light. Sleep
28, 616-623.

Wright, H., Lack, L. C., Tennaway, D. F. (2004). Differential effects of
light wavelength in phase advanging the melatonin rhythm. I Pineal Res., 36,
140-144.

Wright, H.R. , Lack, L.C., and Partridge, K.J. (2001). Light emitting diodes
can be used to phase delay the melatonin rhythm. Journal of Pineal Research,
31(4):350-355.

Wright, H.R. and Lack, L.C. (2001). Effect of light wavelength on
suppression and phase delay of the melatonin rhythm. Chronobiology
International, 18(5): 801-808.

Wright, H. R., Lack, L. C., Kenneway, D. J. (2004). Differential effects of
light wavelength in phase advancing the melatonin rhythm. J Pineal Rec, 36,
140-144.

___

Liron


"Adam Aglionby" wrote in message
...
On 1 Oct, 13:46, "dennis@home" wrote:
"Adam Aglionby" wrote in message

...



On 1 Oct, 10:07, "Mungo \"Two Sheds\" Toadfoot"
wrote:
Mungo "Two Sheds" Toadfoot wrote:

Are they A Good Thing for cheering up a kitchen through the winter,
and possibly having a beneficial effect on the symptoms of SAD? I'm
having some bother finding a 6' one locally but if they're worth
having I'll continue the search.

Si

And... is there any difference between 'normal' daylight tubes and
'full
spectrum' jobs?

added sci.engr.lighting as crosspost from uk.d.i.y

Probably several multiples of price.....

Full Spectrum is marketing mumbo, fluro by the very way it works has a
peak and trough spectral power distribution.
People like the dodgy Dr Ott sell all sorts of impressively packaged
"full spectrum" fluorescent lamps, if you really want full spectrum,
halogen has a continuous spectral output.

Daylight tubes are often just high colour temperature, which in an
internal kitchen might look very cold and as Andrew said can have poor
actual colour rendering. High colour rendering index lamp is really
more what you want, decent lamps made by big manufacturers aimed at
things like the print, textile and car refinishing business be more
appropriate.

Some research says colour does make a difference, been some research
on use of blue LED in resetting circadian rythmns in the elderley,
some research says intensity matters some that time and length of
exposure is most important, doesn`t seem to be a well understood
phenomenon.Offering opportunity for snake oil salesman to enter the
fray.

Probably BS though as sunlight is not blue and its lack of sunlight that
causes SAD.

Cant place the link offhand but it was serious research, blue LED
because its a very efficient generator of blue light aginst tungsten
or even fluro. Sunlight contains a lot of both visible and increasing
amounts invisible blueviolet radiation....

I would use warm white tubes myself and you need plenty of them, one tube
is
not what you usually see to treat SAD, maybe five tubes or a 250w metal
halide lamp?

Intensity dosen`t seem to be universally accepted as the main
factor ,though personally think it is probably one factor.

Adam




Adam

wrote:
On 1 Oct,
Rod wrote:

Sorry - I feel that the 2700K CFLs are truly ghastly for use in the
living room in the evening! Even standard tungstens are a bit too
yellow. Not certain what temperature ours are, 4000K I think, and they
are fine.

Nothing less than 3500k suits me. I used to like the old gas lights, a
greenish tinge in preference to the yellow electric lights. I wonder how they
were in the colour temperature/rendering stakes?


Soft start as well. It wasn't until the end of the 60s that the station
I most used converted to fluorescent. (That, IIRC, means that they had
beeen converted to natural gas a few years earlier.) The change in
colour was horrible - from quite OK to ghastly.

I'd guess that CRI depended on the materials of the mantle (thorium and
cerium oxides?) and its age.

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember (Andrew
Gabriel) saying something like:

Of SAD...
One 6' tube mounted on the ceiling probably isn't anywhere near
enough to make any difference. If you want to make a SAD lamp, the
cheapest way is probably to buy a 4-tube modular ceiling luminare
designed to sit on a 600mm ceiling tile frame (either 600mm square
or 600x1200mm). They're dirt cheap from an electrical wholesaler
and often free from a skip. You can hang it on the wall like a
picture next to where you sit/work, like a sort of fake window.

ding

I have a few of those and made a couple of them up with twice the number
of tubes packed in. Certainly works, and costs next to nothing compared
to what's being asked for 'proper' SAD lamps.
--
Dave
GS850x2 XS650 SE6a

"It's a moron working with power tools.
How much more suspenseful can you get?"
- House

On 1 Oct, 22:22, Rod wrote:
dg wrote:
On 1 Oct, 09:46, "Mungo \"Two Sheds\" Toadfoot"
wrote:
Are they A Good Thing for cheering up a kitchen through the winter, and
possibly having a beneficial effect on the symptoms of SAD? I'm having some
bother finding a 6' one locally but if they're worth having I'll continue
the search.

Si

I am trialling a CFL daylight bulb in the bathroom, a bedroom and
dining room at the moment. They are all nice and bright - 150w
equivalent.

In the dining room, the light is OK in the day as it gives a bit of a
boost to daylight which is coming through the patio doors. But at
night it looks plain odd. Its too white, looks cold, and visually is
less preferable to the warmer CFLs in an adjacent room or the tungsten
spots in the kitchen. It does not promote a feeling of well-being at
night- just a feeling of unnaturalness.

In the bedroom, again it looks unnatural, but is a better light for
getting dressed and for mrs dg putting the make-up on. Its a shock
when the light is put on on during the night after darkness or if
waking up when its dark. It's not as calming as some warm low wattage
CFLs which we have in bedside lamps.

Its not a nice light to wake up.

In the bathroom, its a nice useful light. So this one will probably
stay and the others will be removed.

Full spectrum bulbs are just too subjective - as are all colour
temperatures really.

What exactly is colour accuracy and how is it needed at home? Its a
bit irrelevant

If you are doing photography, or need accurate colour rendition for
some commercial application, then fine, but at home, at night IMO, a
warm yellow is the most "natural"

dg

Sorry - I feel that the 2700K CFLs are truly ghastly for use in the
living room in the evening! Even standard tungstens are a bit too
yellow. Not certain what temperature ours are, 4000K I think, and they
are fine.

Certainly anyone looking from outside might think it cold, but we are
quite happy. And warm. :-)

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org- Hide quoted text -

- Show quoted text -

The ones I have are 6200k

dg