David Livshin is a professional photographer, but for quick shots, he's using his iPhone more and more.
"I just find the opportunity to be unobtrusive sort of wins out over having to lug the cameras around," said Livshin.
But the iPhone camera, like most smartphones, doesn't have an optical zoom.
"Smartphones only have a digital zoom that loses pixels as it zooms in. That reduces image quality," said Terry Sullivan with Consumer Reports.
Consumer Reports tested two new brands of add-on lenses for smartphones. The Olloclip costs $70, and it's a 3-in-1 lens for the iPhone 4 and 4S. It has fish-eye, wide-angle and its macro lenses.
"You fit each of them over the iPhone's lens," said Sullivan.
Consumer Reports also tested add-on lenses from Photojojo that work with both iPhones and several Android phones. The lenses cost about $20 each. To use them, you attach a ring on your phone with adhesive. The lenses attach to the ring magnetically.
"We found the ring sometimes came off the phone when we removed a lens," said Sullivan.
Consumer Reports found a drawback with both brands -- the lenses cover the phones' flash. But in good light, testers found both the Olloclip and the Photojojo lenses can take some beautiful pictures.
"The close-up shots and video of flowers in particular were stunning," said Sullivan.
Consumer Reports says these lenses can definitely expand a smartphone camera's capability. But be aware that the Photojojo only works on phones where the lens is flush with the phone. If the camera lens protrudes, the add-on lens won't attach properly.