Author Topic: LED lightbulbs (mildly obsessive)  (Read 835 times)

Morat

  • I tried to HTFU but something went ping :(
LED lightbulbs (mildly obsessive)
« 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?
Tandem Stoker, CX bike abuser (slicks and tarmac) and owner of a sadly neglected MTB.

Re: LED lightbulbs (mildly obsessive)
« Reply #1 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.

hellymedic

  • Just do it!
Re: LED lightbulbs (mildly obsessive)
« Reply #2 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.

Kim

  • Timelord
Re: LED lightbulbs (mildly obsessive)
« Reply #3 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.
Careful, Kim. Your sarcasm's showing...

Re: LED lightbulbs (mildly obsessive)
« Reply #4 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.
Quote from: Kim
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Giraffe

  • I brake for Giraffes
Re: LED lightbulbs (mildly obsessive)
« Reply #5 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.
2x4: thick plank; 4x4: 2 of 'em.

Morat

  • I tried to HTFU but something went ping :(
Re: LED lightbulbs (mildly obsessive)
« Reply #6 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...
Tandem Stoker, CX bike abuser (slicks and tarmac) and owner of a sadly neglected MTB.

Kim

  • Timelord
Re: LED lightbulbs (mildly obsessive)
« Reply #7 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.
Careful, Kim. Your sarcasm's showing...

Re: LED lightbulbs (mildly obsessive)
« Reply #8 on: March 02, 2020, 09:22:39 am »


<i>Marmite slave</i>

Morat

  • I tried to HTFU but something went ping :(
Re: LED lightbulbs (mildly obsessive)
« Reply #9 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.  :-\
Tandem Stoker, CX bike abuser (slicks and tarmac) and owner of a sadly neglected MTB.

Re: LED lightbulbs (mildly obsessive)
« Reply #10 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.
Get a bicycle. You will never regret it, if you live- Mark Twain

Re: LED lightbulbs (mildly obsessive)
« Reply #11 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.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.