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> There is absolutely no way some translucent face painting does that. Wow what a dismissive comment to chemistry and cosmetics. Just for fun, try take a pic
by csdvrx 4y ago
> There is absolutely no way some translucent face painting does that.
Wow what a dismissive comment to chemistry and cosmetics.
Just for fun, try take a pic of yourself with a UV camera (or just UV light with some phones), and you'll see it's translucent only to the visible spectrum: https://petapixel.com/2016/05/26/tiny-uv-camera-shows-youve-put-enough-sunscreen/ https://petapixel.com/2016/05/26/tiny-uv-camera-shows-youve-...
- derefr 4y agoOne thing I've recently become curious about, is whether the "UV pigments" in sunscreens are color-fast or not; i.e. whether getting sunscreen on clothing gradually tints the clothing darker when seen in ultraviolet, in the same way that getting throwing a non-colorfast red shirt in with your whites will gradually tint them red.
- numpad0 4y agoThe Sun Protection Factor(SPF) is defined "a measure of the fraction of sunburn-producing UV rays that reach the skin" when applied as instructed and only over a defined period, usually 2hr[1]. That means there is twofold difference even between a pane of glass(<1% whole body) and correctly applied sunscreen(~2% for 2hr @ SPF50), before taking walls into accounts. 1: https://en.wikipedia.org/wiki/Sunscreen#Sun_protection_factor_and_labeling https://en.wikipedia.org/wiki/Sunscreen#Sun_protection_facto...
- LorenPechtel 4y agoThis. Note that even single-layer garments generally don't have a protection factor of 100. Simply being outside in warm weather will give you more UV even if you use sunscreen perfectly--and I don't believe perfect use of sunscreen happens in the real world. I don't care how well you apply it, the protection will be degraded by movement. It will be degraded even more by touching things.