How much light do you have in your lab?

[Karel]

https://www.noao.edu/education/QLTkit/ACTIVITY_Documents/Safety/LightLevels_outdoor+indoor.pdf

[SilverSolder]

(Attachment Link)

https://www.noao.edu/education/QLTkit/ACTIVITY_Documents/Safety/LightLevels_outdoor+indoor.pdf

Which is why you need a desk lamp - one that can be pulled close to what you are working on...

[Karel]

Which is why you need a desk lamp - one that can be pulled close to what you are working on...

Which can create reflection and eye strain. It's better to increase the general lighting of the office or lab.

[maginnovision]

30,000 lux you are talking a cloudless summer noon sunshine.

Ok, so maybe it's not that far off then.

[SilverSolder]

Which is why you need a desk lamp - one that can be pulled close to what you are working on...

Which can create reflection and eye strain. It's better to increase the general lighting of the office or lab.

If you use a big lamp (long tubes) you won't have reflection or shadow issues.   It's what architects used to do over their drafting tables before computers took over...

[GreyWoolfe]

I prefer bright lights on my workbench.  I have 2, 4 ft long, 6 bulb LED fixtures from Envirolite that advertise 10K lumens each.  I don't have a lux meter to measure the lux.  Mrs. GreyWoolfe says it's like the surface of the sun but they work for me.

[unknownparticle]

During the day the light through a window is mostly adequate, when I need more, or at night, there is a 10W LED room light, 2 clip on anywhere Ikea LED flex lights and my bench magnifier with LED if needed.  I also use an LED torch for inaccessible area's.  I don't like really bright room lighting, I prefer to use localised brighter light when required.

[technix]

I have 1000 lumens from my bench light, a single 10W LED bulb from IKEA. Then a NeoPixel RGB LED strip at about 750 lumens. That LED strip is programmable.

That's the total light flux from the sources. The illuminance (measured in lux) will depend on how that light flux is distributed geometrically, i.e. how much goes up to the ceiling and into the room, and how big an area is illuminated by the light directed towards your work bench.

Also, take those lumen specs for the LED strip with a grain of salt. In my experience, these values are always hugely optimistic. Try switching between the Ikea bulb and the Neopixel strip (set to white at full intensity), while directing both of them at the ceiling. Do they really produce similar brightness (to within 75%) in the room?

For that I have to build a lux meter. I actually have the correct sensor chips for those, just no board built for them yet. (I will likely run out of by stock of STM32F042 chips for that. THat is such a convenient 20-pin USB microcontroller chip, and I have a bare metal USB stack ready for it.)

[ebastler]

most LED are 120degree dispersion angle ... assuming all things in their places ie led above your head, desk is 1.5m below
the lux landing on the desk is about less than 1/3 or 1/4 or 1/5 ? i cant remember ... there are calculators on web

At a distance of 1.5m, the emission cone from a point source with 120° full emission angle will be 2 * tan(60°) * 1.5m = 5m in diameter. That's a surface area of 20 m². So the lux value on your desk (lumen/m²) will be about 1/20 of the lumen output of your source.

(Simplified estimate; in practice the angular distribution of the emission will not be perfectly even, but will probably favor the low angles and hence the central area.)