Yet Another Cycling Forum

Off Topic => The Pub => Topic started by: Morat on February 27, 2020, 03:21:10 pm

Title: LED lightbulbs (mildly obsessive)
Post by: Morat on February 27, 2020, 03:21:10 pm
Now that we've been in our new house for 18 months, I've realised that my early goal of changing to LED Lightbulbs is a bit overdue so I've started to research.
My wife gets mildly affected by SAD (or SAD like symptoms) and has resorted to a daylight lamp thing in some locations.

I'm wondering if anyone has looked for standard bayonet fitting LED lightbulbs and come up with something that would have a high enough CRI to count as a daylight bulb?
For example the Phillips domestic range tick all the boxes but CRI which is only about 80. Or is 80 good enough?
Title: Re: LED lightbulbs (mildly obsessive)
Post by: Ham on February 27, 2020, 04:41:28 pm
80 is borderline, 90 is better. I found this outfit https://www.ledkia.com/uk/ who have some quality items (Including Toshiba's at 90) and provide CRI info on all. Warning: they are in Spain and my order took about 10 days to arrive.
Title: Re: LED lightbulbs (mildly obsessive)
Post by: hellymedic on February 27, 2020, 05:19:41 pm
What is CRI?
There are other threads in OT Knowledge about LED lighting but they do not cover this.
Title: Re: LED lightbulbs (mildly obsessive)
Post by: Kim on February 27, 2020, 06:24:10 pm
Colour rendering index - basically a measure of how spiky the spectrum isn't.  (Not to be confused with colour temperature, which is a measure of how orange/blue it is.)  It mostly matters for photography and when using the light to mix or compare pigments.

I've no idea how important it is for SAD (presumably it's important to hit the right wavelength of blue to have an effect), but it's generally correlated with higher-quality emitters.
Title: Re: LED lightbulbs (mildly obsessive)
Post by: Diver300 on February 27, 2020, 08:47:35 pm
White LEDs are blue LEDs with a phosphor that absorbs some blue light and creates the other colours. That bit is not far different from fluorescent tubes that create UV light, but in fluorescent tubes all the visible light from them comes from the phosphor.

Multicolour or colour changing LEDs are a combination of blue, green and red LEDs that can each be driven separately to create the colour required.

I don't know if the CRI for a colour changing LED set to white would be better than the CRI for a white LED, but the spectrum would be different, so it could be worth looking at both.
Title: Re: LED lightbulbs (mildly obsessive)
Post by: Giraffe on February 28, 2020, 09:12:37 am
Have a look in Home Bargains: 12W, 1500lm lamps at about 2 quid, 6500K colour-temperature equivalent, don't know the CRI.
Luminous efficacy is moderate, at 125lm/W, but better than most.
Title: Re: LED lightbulbs (mildly obsessive)
Post by: Morat on February 28, 2020, 04:33:50 pm
80 is borderline, 90 is better. I found this outfit https://www.ledkia.com/uk/ who have some quality items (Including Toshiba's at 90) and provide CRI info on all. Warning: they are in Spain and my order took about 10 days to arrive.

That's a interesting site, but I should have said I'm looking for B22 UK bayonet type fittings which makes it a bit harder.

In the end, I've bought a couple of bulbs from here: https://well-lit.co.uk/ - an Astra and a Faye.
They're pricey, but I'm prepared to give them a go if they do the job properly. I'll report back in a few days...
Title: Re: LED lightbulbs (mildly obsessive)
Post by: Kim on February 28, 2020, 05:15:50 pm
In the end, I've bought a couple of bulbs from here: https://well-lit.co.uk/ - an Astra and a Faye.
They're pricey, but I'm prepared to give them a go if they do the job properly. I'll report back in a few days...

I'll be interested to hear if they don't strobe like bastards, too.
Title: Re: LED lightbulbs (mildly obsessive)
Post by: mrcharly-YHT on March 02, 2020, 09:22:39 am


(https://imgs.xkcd.com/comics/stargazing_3.png)
Title: Re: LED lightbulbs (mildly obsessive)
Post by: Morat on March 20, 2020, 08:55:38 pm
Well, my first impression is that their estimated delivery times are a smidgen to the optimist side.

No sign yet. I assume these things are manufactured in China.  :-\
Title: Re: LED lightbulbs (mildly obsessive)
Post by: Canardly on March 22, 2020, 10:26:43 am
Just had a small parcel from China. One week after estimated del date but it got here.
Title: Re: LED lightbulbs (mildly obsessive)
Post by: rogerzilla on March 22, 2020, 04:29:05 pm
I have a 150W equivalent one from eBay.  It is large and might not fit in some shades but it is very bright.