Using flash photography with the iPhone 5S in the dark, at distances further than a few feet away, can cause a whitening of the images. If you must take a far away photo in the dark with your iPhone 5S, we recommend removing the top half of the case before doing so. Below is an example of a photo taken in the dark at more than 10 ft away with an iPhone 5S:
(For iPhone 5 flash test results, see "Other Products")
Unlike with the 5S, our tests using the flash with the Grove Bamboo Case for iPhone 4/4S and 5, Grove SkateCase, and Grove SkateBacks only showed a very slight whitening of the image. In most circumstances, images didn't differ perceptibly, and results varied depending on distance and ambient light. The images below were taken in complete darkness to demonstrate the distortion.
Flash distortion with the Grove Bamboo Case and Grove SkateBack for iPhone 4/4S can be solved easily with the use of a flash-fix sticker, included with any case sold after 5/6/13. These stickers cannot be used with the any other product.