Nothing In Particular

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ed
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#13801 Re: Nothing In Particular

Post by ed »

first there is what
then there is why
and then we get to how....

imo, just saying

of course, it all has to precede
when and who
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andrew Ivimey
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#13802 Re: Nothing In Particular

Post by andrew Ivimey »

Where is usually quite easy!
Philosophers have only interpreted the world - the point, however, is to change it. No it isn't ... maybe we should leave it alone for a while.
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Ray P
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#13803 Re: Nothing In Particular

Post by Ray P »

Nick wrote: Wed Jan 19, 2022 8:54 am Yep, but enquiring minds want to know how its done otherwise it may as well be magic.
I can make some guesses as to how it's done but they would just be guesses - as I've mentioned before, I work with a team that does celestial dynamics stuff, have PhDs in things like astro-physics and have contacts with places like JPL - I'm planning to ask them for some pointers.
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#13804 Re: Nothing In Particular

Post by jack »

Looking for a recommendation for GU-10 50W-equivalent 40 degree LEDs. Probably around 400 - 450 lumens...

I have 45 halogen downlighters to replace and convert from MR11 to GU-10 so don't want to buy a duff make...
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pre65
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#13805 Re: Nothing In Particular

Post by pre65 »

jack wrote: Wed Jan 19, 2022 3:58 pm Looking for a recommendation for GU-10 50W-equivalent 40 degree LEDs. Probably around 400 - 450 lumens...
https://www.bestproductsreviews.co.uk/g ... Z_EALw_wcB
The only thing necessary for the triumph of evil is for good men to do nothing.

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#13806 Re: Nothing In Particular

Post by jack »

pre65 wrote: Wed Jan 19, 2022 4:14 pm
jack wrote: Wed Jan 19, 2022 3:58 pm Looking for a recommendation for GU-10 50W-equivalent 40 degree LEDs. Probably around 400 - 450 lumens...
https://www.bestproductsreviews.co.uk/g ... Z_EALw_wcB
I'm 100% distrustful of "review sites" as many of them are actually owned by shops and manufacturers, thus are completely biassed.

Personal recommendation I do trust.

https://www.wikihow.com/Spot-a-Fake-Review-Website
https://www.forbes.com/sites/christophe ... ne-reviews
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pre65
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#13807 Re: Nothing In Particular

Post by pre65 »

I don't use any GU-10s myself, but, in general, I get my LED bulbs from Screwfix and I've had no reason to say anything bad about them.
The only thing necessary for the triumph of evil is for good men to do nothing.

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#13808 Re: Nothing In Particular

Post by jack »

pre65 wrote: Wed Jan 19, 2022 4:57 pm I don't use any GU-10s myself, but, in general, I get my LED bulbs from Screwfix and I've had no reason to say anything bad about them.
I looked at those but they're all 345lm and I really want 400-450lm else everything is a bit gloomy....
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Ray P
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#13809 Re: Nothing In Particular

Post by Ray P »

Here's a starter for any enquiring minds

https://solarsystem.nasa.gov/basics/chapter13-1/
Sorry, I couldn't resist!
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pre65
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#13810 Re: Nothing In Particular

Post by pre65 »

jack wrote: Wed Jan 19, 2022 5:41 pm
pre65 wrote: Wed Jan 19, 2022 4:57 pm I don't use any GU-10s myself, but, in general, I get my LED bulbs from Screwfix and I've had no reason to say anything bad about them.
I looked at those but they're all 345lm and I really want 400-450lm else everything is a bit gloomy....
I found 500lm & 520lm on Screwfix, but strangely @ 5W

520lm here.

https://www.screwfix.com/p/aurora-ice-g ... tid=479727
The only thing necessary for the triumph of evil is for good men to do nothing.

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#13811 Re: Nothing In Particular

Post by jack »

pre65 wrote: Wed Jan 19, 2022 6:43 pm
jack wrote: Wed Jan 19, 2022 5:41 pm
pre65 wrote: Wed Jan 19, 2022 4:57 pm I don't use any GU-10s myself, but, in general, I get my LED bulbs from Screwfix and I've had no reason to say anything bad about them.
I looked at those but they're all 345lm and I really want 400-450lm else everything is a bit gloomy....
I found 500lm & 520lm on Screwfix, but strangely @ 5W

520lm here.

https://www.screwfix.com/p/aurora-ice-g ... tid=479727
Oddly, I can read and am aware of the Screwfix catalog 8)

500+lm is far too bright for most domestic settings - more like an 80W halogen, that would be why I very specifically mentioned 400-450lm...
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pre65
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#13812 Re: Nothing In Particular

Post by pre65 »

jack wrote: Wed Jan 19, 2022 6:50 pm
I looked at those but they're all 345lm
Yes, but you also said the above. :?

What's a man to think ,eh ?
The only thing necessary for the triumph of evil is for good men to do nothing.

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vinylnvalves
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#13813 Re: Nothing In Particular

Post by vinylnvalves »

jack wrote: Wed Jan 19, 2022 3:58 pm Looking for a recommendation for GU-10 50W-equivalent 40 degree LEDs. Probably around 400 - 450 lumens...

I have 45 halogen downlighters to replace and convert from MR11 to GU-10 so don't want to buy a duff make...
I only have about 12 of them installed, I generally find the selection in toolstation better than screwfix. Much of a muchness on quality It all depends on whether you want warm or cold light too. I used to buy premium brand ones but have found the midrange ones last as long. https://www.toolstation.com/lighting/gu10/c1415?page=2
I don’t find the light dispersion of the ones with 3 leds without a diffuser are good for general downlighting. The only ones I have issues with are the ones that I got to replace compact fluorescent bulbs.

I have used this company too, and haven’t had an issues with their products , will get a discount for quantity too. https://ledhut.co.uk/collections/led-sp ... 9fa07cbc15
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#13814 Re: Nothing In Particular

Post by Ray P »

Ray P wrote: Wed Jan 19, 2022 6:35 pm Here's a starter for any enquiring minds

https://solarsystem.nasa.gov/basics/chapter13-1/
Dr. Steve at work shared his understanding of how the James Webb telescope will operate when in observation mode - apart from being tasked with its observation target from the ground station it is autonomous because the latency of ground-based control will be too high. The satellite has a (relatively) low resolution 'aiming' system that slews the telescope towards a reference point (a known star) to get it pointed in the right general direction, after which a hi-res system takes over to stabilise the telescope with respect to its observation target - he thinks this will be accurate to around 0.5 arc seconds (or better) - that's about 1/7200 of a degree - to keep images 'sharp'. Slewing and correction are achieved with a control movement gyroscope.

I'm a lot less knowledgeable about these things than Dr. Steve so hopefully I've got it more or less right in the relaying...
Last edited by Ray P on Thu Jan 20, 2022 1:06 pm, edited 1 time in total.
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#13815 Re: Nothing In Particular

Post by Neal »

jack wrote: Wed Jan 19, 2022 6:50 pm
pre65 wrote: Wed Jan 19, 2022 6:43 pm
jack wrote: Wed Jan 19, 2022 5:41 pm

I looked at those but they're all 345lm and I really want 400-450lm else everything is a bit gloomy....
I found 500lm & 520lm on Screwfix, but strangely @ 5W

520lm here.

https://www.screwfix.com/p/aurora-ice-g ... tid=479727
Oddly, I can read and am aware of the Screwfix catalog 8)

500+lm is far too bright for most domestic settings - more like an 80W halogen, that would be why I very specifically mentioned 400-450lm...
Nick, I’ve been using the Aurora warm white GU10 5w, 500lm or 380 useful lumens. EN-GU0005/30. They are none dimmable though.

https://www.cef.co.uk/catalogue/product ... lamp-3000k
Only the Sith deal in absolutes.
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