On Tuesday, 28 November 2017 16:34:50 UTC, Martin Brown wrote:
On 28/11/2017 16:01, whisky-dave wrote:
On Tuesday, 28 November 2017 14:14:36 UTC, Rob Morley wrote:
On 26 Nov 2017 18:29:33 GMT Bob Eager wrote:

On Sun, 26 Nov 2017 18:03:40 +0000, Andrew wrote:

On 26/11/2017 16:59, Peter Parry wrote:
[...] [...] [...]
Surely staring at a computer screen to keep up to date with
uk-d-i-y is as good as any other solution.?

Is there a program that displays the correct light on a nice big
computer screen?

I don't think the precise spectral content of the light matters as
long as it's well bright and whitish.

No it is the exact spectral content that is important, that;s one
reason why they were expensive as you needed blue light which wasnlt
easy to 'make'.

That is what the vendors would have you believe and to some extent it is
true but the LED technology is to make blue light very efficiently and
use it to excite a broadband yellow phosphor for a white.

But you do need that 'special Blue' LED normal blue LEDs just don't produce the correct wavelengh at sufficinet brightness. Things are better now but a friend of mine was seeing a specialst at a hospital near trafalgar square and was having SAD sessions in the mid 90s.

It is trivial
to mix in extra blue LED during build (just as it is trivial to omit
green LEDs in magenta arrays intended for horticulture).

But you still need the correct one, not just any blue will do.

Not sure how valid this is but.

http://www.independent.co.uk/extras/...-a6839106.html



Fish tank people have a range of choices.

FISH TANK PEOPLE ! I think you mean Aquarists.

I had 3 'tanks' in the ealry 90s.
Thre wasntl one light that wass the best for everything, some lighting was to show off the fish others for the plants.


http://www.drsfostersmith.com/media/...rumGuideFW.pdf

What you really need is full spectrum SAD.

http://www.sad.org.uk/buying-a-sad-light/

Semi-SAD or just a bit MOPPY won't do it ;-)

Bright enough and bluish will be good enough.

Depends how bad your SAD symptoms are.


Conversely if you use a computer late at night having the colour
temperature go lower after dusk will make it easier to sleep.

I think that depends more on what you are looking at ;-)
and it certainly isn't the answer if your interested in photography.