231–240 of 294 posts
The article didn't mention anything about vitamin D, which I probably care more about than feeling like the artificial light is real sunlight.
It’s not that crazy of an idea especially in winter when SAD is worst and any extra power you waste in your house heats it so it isn’t really wasted. One of my favorite places on earth is my marijuana grow and the incredible amount of beautiful light they grow under. I’ve contemplated a scaled down version in my house. I could grow plants all over the place under the lighting like being outside, no matter what the se…
According to what I've found, grow lights can emit enough UV rays to make them (unfortunately) a non-starter for inside your home.
"commercially available LED light sources (for horticultural or other applications) can be considered human safe when designed, installed and used in accordance with the applicable standards, regulations and manufacturer’s instruction"
https://www.valoya.com/the-effect-of-led-grow-lights-on-huma...
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Yuji does indeed make the good stuff, just really in a consumer-friendly form factor unless you count the low-power bulbs. For your sunset approximation, you could add some warmer ones and fade over; they also have some dual-color strips with two different color temperatures evenly spread to allow for seamless mixing.
Exactly. You’d probably need fewer of the warm colored strips, because at the time of day when you will want to use them you’ll also want less light anyway.
(I'm using a 20W/m 5m strip of BC-series 1900K for my living room, along with a 10W 4000K bulb hanging from the ceiling.)
For a year I had my home office setup with LED strip lights all the way around the room. They were mounted on a narrow shelf encircling three walls. Color temp was about 6000K. I loved it, for a while. It felt like a fresh bright day. However, after some months of 12 hours a day of working in this environment, I started having pain in my eyes, almost as if they were being squeezed. This discomfort persisted for a mon…
"blue light is harmful" is a highly debated topic. Iirc there is no consensus yet and some studies indicate that it's not a health risk. Apart from that, having a screen that is too bright can certainly cause problems. Especially if the contrast is very stark to the surrounding environment. I personally use a light theme when it's very bright outside/inside and a dark theme when it's dark + my monitor brightness at h…
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Quick guide to CRI 90-95: Can be ok, or not. Depends. Different lights will likely not mix at the same color temperature. 98: Good 99-100 full spectrum cyberlight: As good as Halogen and only ~30x as expensive.
R9 is also important in the higher CRI ranges. CRI is based on pastels - it's an artifact of measuring traditional florescent bob performance - and R9 captures the vivid reds that are important to truly accurate color rendition.
SSI - spectrum similarity index - is probably a better measure, because it doesn't look at a few colors, but at the entire spectrum, and so heavily punishes peaky and discontinuous spectra as produced by many LEDs. High SSI values also result in much better mix-and-match behavior of light sources. Even CRI 95 LEDs often don't mix well, usually on the pink-barf-scale (tint).
For anyone interested in doing real lighting CAD and simulation, one of the true professional-grade tools for architectural lighting design is available for free. Dialux Evo is a great tool, though there's a bit of a learning curve.
The price has little to do with the R&D and manufacturing cost, it really has to do with how small the market is. Once you have a customer that is willing to pay $1,000 for this novelty, they will likely also pay $10k for the novelty.
Also....I seriously doubt artificially extending daylight hours is good for anyones health.
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My guess is it's some complex neurological response triggered by 'knowing' (or being sufficiently convinced) that one is surrounded by bright outdoor sunlight, rather than a physiological response powered by the light absorbed by the retina. What matters is the brain's estimate of the current lux value, which would take pupil size into account. This is just a guess.
1. It's not all about eyes. The skin also reacts to light. 2. Even though your pupil shrinks, you get a larger total number of light rays into the eye. Your visual cortex adjusts the image so you don't realize that a sunlit scene is a million times brighter than a lamplit scene. These extra rays may still affect something hormonal.
So a sphere of 2m radius has a surface of about 50 m^2.
A 1000 lumen bulb illuminates the sphere with app 1000 lm / 50 m^2 = 20 lux (not 50 lux as OP wrote).
So the calculation is a bit off. OTOH if we had bulbs that shine downwards only it would be sufficient to just divide by the floor. So 100,000 lm in a 10m^2 room gets you 10,000 lux.
When I lived in Seattle, my solution was a 2’ square fluorescent panel I got from a gardening supply place called “The Indoor Sun Shop”. I grew up in the South and got real bad seasonal depression up there; it probably saved my life. I paid all of $300 for it. Plus like twenty bucks for a mechanical timer, because I discovered that there were a lot of mornings where I was too depressed and mopey to turn it on myself.…
there was a post a day or two ago about vitamin D3, as well as academic literature finally catching up to medical science vis a vis vitamin D3. I won't cite, but only because i don't have a way to index my personal PDF repository, but the common consensus among people who study such things is that anyone living above the 20th parallel (or below, technically) absolutely must supplement vitamin D3, as even a full day i…
I've always been wary of going up to max-dose levels for that reason.