Re: Another review of the cheap focalprice goggles! (LPM Image Heavy)
My goggles arrived yesterday -
broken in the middle 
But judging by my pair it's ultimately a design/manufacturing fault. The goggles consist of a frame made of soft plastic & a single piece of harder laser-protection glass covering both eyes. If you look at these pieces from above - both are U-shaped, but the frame is broader. Thus when fit together, it takes form of the harder glass, but the frame is constantly applying pressure on it in an attempt to straighten. This holds the 2 pieces well together, but apparently also often results in broken goggles.
But FP could do something about packaging - they could ship in a cardboard box and charge 9$ (I'd pay an extra buck for a safe arrival). IMHO even shipping the goggles with the 2 pieces bubble-wrapped separately would be fine.
What bother me far more is the quality of the laser-protection glass itself. Judging from the different reviews (including this one), I expected it to be around OD 2 for green-violet. That's why I ordered mine. I've seen the different pics showing lasers shining through them and the only thing seen is IR dot. Well, it doesn't work that way with mine. It took me a lot of effort to take this single picture of an IR dot:
And to take it, I placed 2 layers of this glass together and shone on a white wall with little ambient lighting. All other photos either showed green, or nothing at all (I almost reached the conclusion that my laser has no IR output :crackup
. Now compare that to a single layer of protection glass:
Direct view with camera. Left - laser on wall. Right - laser through glasses on wall. While weak, the dot is clearly visible as green.
Direct view with camera. Top-left - laser on wall. The rest - laser through glasses on wall. Again, visible green dot.
Laser on wall. Left - direct view with camera. Right - view with camera through glasses. Camera can see a green dot.
All the photos are unedited (only crop and resize, all pictures on a single image are at the same scale), and they are very similar to what I see with my eyes. I wish I had an LPM to measure how much of green it lets through, but I don't. The laser I used is the green disco 30mw reviewed here earlier (to estimate power - it can burn plastic bags when I put a black dot on it, and when used with a magnifying glass it can heat to smoke a tiny dot on black tape, visible nighttime beam, dot visible at a km-distance, maybe more). With these glasses on - no beam, dot visible up to about 50m, when burning (with magnifying glass) - tiny, but very bright green dot is visble on the black material.
I'd like to hear your opinion. If it's indeed a faulty pair (hopefully not a whole faulty batch that FP might send to unsuspecting customers), just how much of mw green do you think a single layer lets through (if that can be at least approximated according to the photos), i.e. what can these be used for? Common sense tells me a direct hit (and even a fully reflected hit) is a no-no with these glasses (even with 30mw) - the dot through the glasses appears somewhat brighter than a common keychain red laser dot without glasses. But would it be safe for use when burning with a 30-50mw laser? Or maybe, due to the way my pair is broken, I should DIY a single eye goggle (eyepatch + dual glass)?
