Smartphones and digital cameras are designed to only capture visible light. They purposely filter-out the spectrum of light used by Sunscreenr to "see" sunscreen.

For those those want to know the technicalities of why:

- The image sensors in color digital cameras and smartphone cameras have a special filter (Bayer filter) that let's them "see" regular colors (red, green, blue) and that filter just about eliminates the ability of the sensor to respond to the UV spectrum.

- Lens elements in regular cameras and smartphone cameras are made from materials that have antireflection coatings that actually block most of the UV spectrum.

- Camera lenses are designed to capture and focus light. Lenses that are made to work for visible light (like in your smartphone) do not focus UV rays properly.

No. Sunscreenr is made possible by the combination of several key components: a special filter that removes all light except the part of the spectrum that sunscreen absorbs, a completely custom lens made from special materials and a carefully selected sensor that can actually respond to UV light. That hardware is combined with our proprietary image processing algorithms to deliver an image to you that shows where sunscreen is on your skin. Protected areas appear dark and unprotected skin appears light.

Sunscreenr™ is designed to an IP rating of 67 and will be tested to MIL STD 810g-516.6. What does all of that mean? It means that no sand or dirt, even as fine as talcum powder can get into Sunscreenr. It also means that Sunscreenr is not just splashproof but can withstand being underwater up to 3 feet for 30 min. Sunscreenr is designed to handle your little one dropping it in the shallow end of the pool! The MIL STD testing means that Sunscreenr passes the same ruggedness tests as the gear soldiers take into battle. However, like any optical device care should be taken to prevent dirt, dust, and fingers from scratching the exterior lenses. When not in use, Sunscreenr should be stored properly.

Yes, although some may find that the display inside of Sunscreenr appears sharper with glasses off. It all depends on your eyes and what kind of prescription you have. We have worked with an optical engineer and have consulted with several optometrists to make Sunscreenr as easy to use a possible for the broadest range of people. If you use Sunscreenr with your sunglasses on you may find that the display looks slightly dimmer.

Sunscreenr has been designed with a rechargable battery that should last for several days with normal usage. An auto-off feature keeps the battery fresh in case you forget to turn it off. Sunscreenr recharges using any micro USB charger (AC or car charger is fine).

Sunscreenr's viewfinder is designed to work on the brightest days, in the brightest places -- beaches, pools, ski slopes, etc. -- to let you see the images. A regular screen can be very hard to see in bright sunlight and often appears washed-out. An additional benefit of the viewfinder is that it allows us to more easily make Sunscreenr rugged and waterproof.

Yes! The contrast between unprotected skin and protected skin is less dramatic than for people of lighter skin color. Unprotected areas will appear lighter and areas covered with sunscreen will still appear darker. Sunscreenr's algorithms work to make this contrast as large as possible.

No worries! Wipe off the excess, wash Sunscreenr with soapy water then dry it off and you're good to go.

Any Broad Spectrum sunscreen (cream, spray or powder) that's at least SPF 15 will be visible through Sunscreenr™.

Yes! Areas of thin coverage will not appear as dark as areas that are well covered.

No worries! Sunscreenr has been designed to be able to record and playback a short video. Just hit the "record" button and point Sunscreenr at yourself (you can use a selfie stick, your hand or any standard camera tripod). It will automatically record for 30 seconds and then stop. To see your coverage, just hit the "play" button and look into the viewfinder.