Camera review: iPhone 5S vs Lumia 1020 vs Galaxy S4 zoom

Sunnyvale, California: I used to cringe when I'd see people capturing precious memories with their smartphones. Although most smartphones have megapixel counts similar to what stand-alone cameras offer, they have been inferior in lens quality and manual controls. Images have never been as good... until now.Over the past two months, I've shot more than 3,000 test photos in four states using nine camera phones, a point-and-shoot camera and a high-end, single-lens reflex camera (also known as an SLR). None of the smartphone cameras are good enough to replace a $1,000-plus SLR, but I'm surprised how well some of the phones did, particularly in low-light settings that challenge even the best cameras.Three phones stand out: Nokia's Lumia 1020, Samsung's Galaxy S4 Zoom and Apple's new iPhone 5S.The Lumia 1020 squeezes a lot of camera innovations into a small device. It can take photos as large as 38MP, which means you can crop the image to a quarter its size and still have enough detail for large poster-size prints. With smaller files, you're limited to smaller prints when you crop.Thirty eight megapixels is about three times the 13MP on Samsung's regular Galaxy S4 and nearly five times the 8MP on the iPhone 5S and 5C. It's also more than what many SLR and point-and-shoot cameras offer. The downside: The Lumia runs Microsoft's Windows system, which has relatively few apps from outside parties.The Galaxy S4 zoom works much like other Android phones from Samsung, except that it has a real zoom lens, offering up to 10 times magnification. Other camera phones have digital zoom features, or magnification using software, but all that does is blow up shots without boosting clarity. With the optical zoom found in the Galaxy S4 zoom and standalone cameras, you retain the sharpness as you zoom in. The Zoom's 16MP is better than most phones. The downside: It's not available in the US yet.The iPhone 5S, meanwhile, has a better camera than last year's iPhone 5. The resolution remains at 8MP, but the camera is able to sense light better because individual pixels are larger and the shutter can open wider. The downside: It's behind in megapixels.Many of the differences in images are subtle, but every bit helps when making prints or viewing on bigger screens.Low-light shotsThe Lumia is the most consistent of the three at getting good night and indoor shots. Friends have marvelled at photos I've taken in bars without the flash.Using a technique called oversampling, the Lumia squeezes 38MP worth of data into a 5MP image, a size more manageable for sharing. What that also does is combine the small amount of light from multiple pixels into one, resulting in better lighting. An image stabilizer compensates for shaky hands.Apple takes a different approach with the iPhone 5S. Instead of adding more megapixels, it makes each pixel larger - 1.5 microns, compared with 1.12 microns on the Lumia. The new phone also has an image stabilizer and a wider shutter than previous models. Its flash produces two bursts of light at once, each slightly different in color and automatically adjusted to match ambient lighting. It is a technique I have never seen before in a camera - phone or otherwise - and results in better skin tones and more natural colors.A photo of my Sunnyvale hotel's illuminated sign in the distance came out sharp on the iPhone 5S. Many cameras overcompensate for low light by making the few points of light too bright. With some cameras, the "O" in "Sundowner" didn't look like an "O" but a solid dot. iPhone 5S kept the letters clear. The Lumia also did that and went further than the iPhone 5S in keeping the darker parts of the hotel building looking good, too.Nokia talks about "reinventing zoom." Even as the Lumia squeezes all those pixels into a 5MP image, it retains the full version for you to crop and blow up later. One nice touch: Even if you use the camera's digital zoom to focus in on a subject, it still retains the rest of what the camera sees. Other cameras throw out that data. So your 5MP version will focus in on what you want to quickly share, but you can go back to the larger version to discover something you might have missed in the surrounding area.But digital zoom is digital zoom and won't replace what a real zoom lens can do. Among the three phones, only with the Galaxy S4 zoom was I able to make out faces of band members at a recent concert in New York.Everyday shotsBoth the Lumia and the Galaxy S4 zoom offer a greater range of manual controls than typical camera phones. A Grip attachment for the Lumia also has a hole for screwing the phone onto a tripod. But if I'm going to take special shots requiring manual controls or a tripod, I'm also likely to have my SLR, which has a powerful lens that can't possibly be squeezed into any smartphone.