Aurora Aperture- Power UV 39mm (the toughest filter)
Ultra Violet (UV) filters have been around for long time from the old film days. Their original purpose is to block UV light that would cause hazing in old film photos. Even modern films before digital photography are immune from UV light, digital cameras are not sensitive with UV light either.
In the meantime, users believe having a relative inexpensive filter in front of their expensive lens could provide some levels of protection, thus UV filters today are still widely used as a protection filter and they are the first accessory to buy with a purchase of a new lens.
However, most UV filters and protection filters in the market are made from a piece of thin glass. They offer little physical protection since the filter glass is easy to be broken, as discovered by users who have dropped their filters by accident.
To demonstrate the impact resistant capability of the Gorilla® Glass 3 based PowerUV filters, we conduct a drop-ball test. The drop-ball test is based on the ANSI Z87.1-2003 standard which is used in the FDA 21 CFR 801.410 regulation. The original purpose of this test is for eyeglass certification and has been used over forty years. All eyeglasses and sunglasses sold in the US must pass this drop ball test.
In this impact test, a 5/8-inch steel ball weighting approximately 0.56 ounce (about 16 grams) is dropped from a height of 50 inches (about 1.27 meters) upon the surface of test target, and the test target must not be fractured.
As seen from above, all these UV filters failed the drop ball test, including a few premium brand filters such as Kenko Pro1D UV and B+W XS-Pro UV. Some UV filters did not even pass the test with a smaller steel ball of 7g, or less than half of the standard weight at 16g.
There is no surprise for this, since these filters are not built as real protection filters from the first place. We just want to use the test to break the illusion of traditional UV filters can provide protection to camera lenses.
Now we put our PowerUV filter through the same drop-ball test. Not only it passed the standard test with flying color, we tried to break it by increasing the weight of the steel ball to 2 ounces (56 grams) , our Gorilla® Glass 3 based filters still pass the test. That is up to 3.5 times of standard test weight and 8 times of certain ultra thin UV filter failed limit.