If you have a smartphone, you likely take lots of pictures with it. So why would you ever need a stand-alone digital camera?

That's a question many consumers are asking. Digital camera sales are falling, while smartphone sales soar. Consumers are taking a large and growing portion of their photos on their phones. For several years now, the most popular camera among users of the popular photo sharing site Flickr has been the iPhone.

With a smartphone, "I can do all my creativity on the same device that I took the picture with," said Chris Chute, an analyst who covers the digital camera market for IDC, a technology research firm. "That's a value proposition that's very difficult to match."

But Chute and other digital imaging experts say that despite the advantages and popularity of smartphones, there remain compelling reasons to have a digital camera. They offer higher-quality images, particularly in low light. They offer powerful zoom features unavailable on smartphones. And some models come in rugged cases that resist drops and water.

What's more, camera makers are learning from the success of smartphones and adopting some of their features, such as the ability to connect to the Internet or run apps.

"Smartphones and cameras can clearly coexist," said Liz Cutting, a senior imaging analyst at market research firm NPD Group. "They just have different places in consumers' lives."

One way cameras outperform smartphones is with their lenses. Even low-end point-and-shoot cameras these days offer five times optical zoom lenses. More expensive models offer up to 50 times optical zoom lenses. Zoom lenses are useful for taking shots from far away — say, at a child's soccer game or a recital.

While you can zoom in on an image in a smartphone, what you are actually doing is cutting out and focusing in on just a portion of what the image sensor is detecting. This typically leads to much fuzzier pictures than what you can get with a true zoom lens.

Terry Sullivan, associate editor of digital imaging at Consumer Reports magazine, said he recently tested a Canon SX50 camera, which has a 50-times optical zoom lens. He used it to take a picture of the moon and was able to zoom in enough that he could see the moon's craters in the image. That's something he couldn't do with a smartphone.

"It was really extraordinary," Sullivan said.

Stand-alone cameras also have an advantage in their image sensors, which generally are larger than those found in smartphones. The larger sensors can collect more light, allowing the cameras to take better pictures at night and in dark rooms. The larger sensors also allow more space for their pixels, allowing them to shoot higher resolution, less grainy images.

You can also find stand-alone cameras priced between $100 and $400 that can go 30 or more feet underwater and survive drops of 5 feet or more. Smartphones can typically survive similar conditions only with special, sometimes pricey cases.

Digital camera makers are trying to make their products more appealing to customers not just by distinguishing them from smartphones, but by making them work better with smartphones or, in some cases, work more like them.

A growing number of cameras include Wi-Fi radios that allow users to upload pictures directly to Facebook or e-mail them to friends. They can also use those radios to transfer pictures to their smartphones and to use their smartphones as a remote control for their cameras when taking self-portraits. Three different cameras either on the market or soon to come include the Android operating system. Those cameras allow users to shoot and edit pictures with some of the same apps they'd use on their smartphones.

So while smartphones have become popular cameras, digital cameras are far from obsolete. Given their advantages over smartphones, "there's a clear reason to continue buying a camera," Cutting said.