Hi All:
I plan to make a blog post on this on my website when I get a chance, but most of the info is now posted on my website. In July, I ordered a 30 pack of these cardboard eclipse glasses containing six different styles off of Amazon. At the time I wasn't paying attention to where they were manufactured, but when they arrived on July 19th, I discovered they were shipped from China. I didn't have a chance to even look at them until this weekend, and thought I'd share what I found.
At the same time, I also bought these plastic glasses off of Amazon. While I generally suspect these are safe, the labeling is even less convincing that they are ISO 12312-2 compliant.
I did various visual tests, both indoors and out, but for comparison photos I turned on my cell phone flash LED and took pictures through each filter to get an indication of their performance. All shots were at 3200 ISO for 1/60th of a second at f/5. I may try to repeat this for IR and UV LEDs that I have available, using my unfiltered camera, but we'll see when I can get to it. Ideally if someone out there has access to a spectrometer and could do a good job of it, it would be a great service to the community to know if these are legit or not. At any rate, here's the LED which is obviously blowing out the histogram completely.
Here are the plastic solar eclipse glasses with the silver lenses. For white light these work great. You can see light coming around the side, but very little of the LED through the lens. Likewise, looking at an indoor light you can't see anything, and with the Sun you have a nice comfortable view of the solar disk. The question is whether or not their safe at UV and IR. Probably with the silver coating, but who knows?
This is one of the better paper glasses. It does an ok job of filtering the light, but you can still dimly see a 100 watt bulb through it. Viewing the solar disk is generally comfortable, but not as good as the plastic glasses.
Just for comparison, the filter's doing a much better job of blocking the light than the paper, although the paper difuses the light it lets through. Still, I doubt anyone would go blind looking at the sun through the paper, but I can't say I've tried it!
Here's the LED through the US Flag version that did not perform well at all (all of those on the right of the first picture are similar). This one you can clearly see normal lights through, and viewing the sun is not comfortable at all, with lots of flare and illumination of the surrounding area. Stacking multiples is too dark to see anything, although using this in conjunction with a good pair of polarizing sunglasses gives an adequate view of the solar disk. Again, who knows about IR or UV though.
I look forward to everyone's comments.
Beo
