Not an expert, just someone who wants good lights for good gains in vision…
Advanced warning: no real conclusion in this post.
In my view, everything depends on the actual bulbs as the same specs from different manufacturers have completely different actual lights.
A few years ago I purchased a desk lamp with 5 Lighting Modes with 7 Brightness Levels, 12W from 2700k to 6000k. Actually the first one was rubbish so I returned it. The second one gives me 1000 LUX right under the light, 500 LUX near it and 300 LUX within the desk area. (I have a handheld LUX meter to measure it)
Something like this - but I would never keep the room dark around me:
At the previous places I typically had warm white spotlights in the ceiling in the living area and I liked them, sitting under one was enough for reading (that’s about 400+ LUX for me) but they were not too bright. Now I have an ugly chandelier with 5 arms without shades around the bulbs and all original bulbs broke within a short time. So I changed bulbs a few times recently - cheaper than upgrading the place for the owner completely…
I started with halogen saver bulbs 42W (equals traditional 55W) promising 2700k. I expected it to be near as bright as the desk lamp. But it only provided 300LUX sitting right under the lights and 150 LUX if moving to the other end of the 2-seater sofa.
Changed the bulbs to LED 28W, then to LED 42W (promising 2700k) - slight improvements only.
So I thought there can be no harm in trying 12W LED corn bulb (equivalent to 100W halogen) with 360° beam angle. Like this:
First try was with 6000k cold white, having the vision for a super sharp Snellen It was so bright as walking to full summer sunshine from the cellar, just happened to be in my living room any time I switched the lights on… It was like that even with the weather being at its best winter sunny outside. It was definitely too much, completely disturbed my circadian rhythm though at last changed the LUX to 450 - 550. Now I have the same 12W LED corn bulbs but with 3000k warm white and I think I’ll stay with them. Same 500 LUX, but the overall feeling is more cosy.
By now I don’t understand anymore how W vs k vs LUX should work. But I got to my preference via trying. Luckily I got refunds for all earlier tries!
I’d say the most important is to have good flicker free lights and to know if it really manages to imitate sunshine with cold white it may be a Mediterranean super sunny imitation - when the Spanish prefer to lie down for a nap during siesta instead of being outside and get a heat stroke… Could be OK in a desk lamp, but too much for a full room.
And while good lights are important, it is also important not to have extreme contrast between the working / reading lights and the background in the peripheral vision.
What did you go for after the initial post?