Some of the lenses come with their own smartphone cases. We found all the lenses relatively easy to use, though they do require you to take your smartphone out of its protective case. On balance, they outperformed the phone's built-in digital zoom and allowed us to take closeup photos that we liked. It can generally be corrected with image-editing software.)īut that doesn't mean the telephoto smartphone lenses aren't worth buying. (The effect is also known as purple fringing, since it often appears as a purple outline around the subjects. They also produced chromatic aberration, a defect in which a lens fails to focus different wavelengths of light on the same place, resulting in a purple or magenta “ghost” image. All the lenses showed significant distortion, particularly in the corners of the images. Most of the lenses improved sharpness in the middle of the images, but the photos were noticeably blurry in the corners.
In the lab, we looked at the images the lenses produced for sharpness, distortion, color accuracy, and light falloff-higher-quality lenses tend to maintain more-even lighting from the center of an image to the edges.
We bought four different telephoto smartphone lenses that would fit on an Apple iPhone 6s, which we had chosen as our test phone.
