*Correction on Thorium Oxide. Thanks to Ken Wheeler for the clarification. My bad for rushing adding the last two bits in the video before going away on a trip (bad enough that I’m not putting enough vids out) . Just want to add:
1. When I say “fear not it doesn’t even penetrate skin, not even paper” I am referring to the Alpha particles.
2. “has a certain death element to it, the thorium coating that is…coating might turn yellow as a result” should be “has a certain death aspect (not element) to it, the thorium element that is…coating might turn yellow as a result”…Thorium Oxide (and Lanthanum) were part of one of the elements as you said and the coating turning yellow is a reaction…there have been uses of coatings that are radioactive, and I believe Kodak did it with a Thorium Fluoride for anti-reflective purposes.
Point is: I could be wrong on this, but if you’re using this lens as it’s supposed to be (i.e. to take photos of stuff, not putting the rear of the lens over your eye for a long period of time, or crushing up the glass to make a smoothie) it’s surely not going to pose a significant health risk, right?
Yonguo 50mm f/1.8 for Canon:
Yonguo 50mm f/1.8 for Nikon:
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