Nokia says it "reinvented zoom" with the Lumia 1020, but how does it stack up to the zooming prowess of a compact camera?

In case you've missed the last couple months of excessive media blasting, Nokia's been diligently working to keep its 41-megapixel Lumia 1020 front and center by putting it in the hands of famous photographers and explaining how it works via sophisticated computer animations.

Amongst the claims it's made about the Lumia 1020 are those about "reinvented zoom," extolled in this commercial that shows a roomful of parents at a school play clamoring for a closer position as they snap photos with their non-Nokia tablets and smartphones while the Lumia 1020 wielding parents calmly zoom into their photos shot from the back of the room.

As we explained in our full review of the device, the Lumia 1020 does deliver more advanced zooming capabilities than its camera phone competitors. 

On most smartphones digital zoom simulates optical zoom by cropping the image and then upsampling it to the camera’s native resolution. The pixels are enlarged while image resolution and image quality are reduced. But the Lumia 1020’s high 41MP native resolution (maximum output  is 38MP in 4:3, 34MP in 16:9) means that even with some digital zoom applied, the image is still downsampled through most of the zoom range. You can zoom into 2.7X (a 74mm equivalent in 4:3 mode) before the cropped image hits 5MP.

But how does the Lumia 1020 stack up against a compact camera with optical zoom?

The Canon PowerShot S120 offers 5X optical zoom with an equivalent focal length of 24-120 mm and a 12MP 1/1.7" backside-illuminated sensor. (For comparison, the Lumia 1020 offers 25mm equivalent focal length in 16:9 and 27mm in 4:3, and a 1/1.5" backside-illuminated sensor.) The Canon's optical zoom works by physically changing the focal length of the lens.

We recently put the Lumia 1020's and Canon PowerShot S210's zoom capabilities to the test. As you'll see in the first table below, we're comparing the Lumia's 27mm wide angle equivalent full resolution 38MP capture to that of the Canon's 24mm wide angle 12MP capture. We're also comparing both cameras at their full zoom capabilities: the Lumia's 2.7X digital zoom produces a 74mm equivalent 5MP capture while the Canon can zoom to 5X for a 120mm 12MP capture.

The full scene from the Lumia 1020 without zoom. The Lumia's fixed lens offers a 27mm equivalent focal length in 4:3 format.
The full scene using the Canon S120 without zoom. Note that the Canon provides a wider view from the start at the wide 24mm focal length of the lens, without as much lens distortion as the Lumia 1020.
The Lumia 1020 fully zoomed in to its maximum digital magnification, an approximately 74mm equivalent.
The Canon S120 fully zoomed in at 120mm is able to get quite a bit closer than the Lumia 1020.

Now let's take a closer look at a 100 percent crop from the full resolution 38MP Lumia 1020 image at the widest 27mm equivalent focal length and compare it to 100 percent crops from several images shot at different focal lengths using the Canon S120. Each original Canon image is a 12MP file; the lens changes the angle of view but the megapixel count stays the same. The Lumia image is exactly the same in each comparison, while the Canon images will show where an optical zoom differs. 

A 100 percent crop from the full resolution 38MP Lumia 1020 image at the widest 27mm equivalent focal length in 4:3 ratio. Each image in this column is identical.
A 100 percent crop from the 24mm wide image from the Canon S120. At this perspective, the crop from the Lumia shows better detail and sharpness as it's taken from a 38MP file versus the 12MP file from the Canon.
Here we compare a 100 percent crop from a 28mm capture from the S120 on the right for a more direct focal length comparison between the two cameras. 
Again, the Lumia offers better definition and sharpness at this point.
At 50mm, the magnification is nearly the same between the Lumia image above and the Canon on the right. 
The two devices offer nearly the same quality of image as we can see in these 100 percent crops. It is also interesting to note the color of the sky here. As in each example, the slightly oversaturated Lumia image is pretty, but the Canon rendition is probably most accurate.
At 70mm, we can see that the optical zoom of the Canon image at right is offering a larger, sharper image than the Lumia image above.
However, the Canon also begins to exhibit some lens flare around the letters here, an unfortunate optical phenomenon the Nokia doesn't exhibit. 
This final comparison shows how optical outperforms digital zoom when we look at the 100 percent crop from the 120mm fully zoomed Canon S120 capture on the right versus the Lumia image above.
Lens flare is even more pronounced in the Canon example above.

Our results show the benefits of zooming in with a compact camera over even the best-in-class smartphone. The Lumia 1020's digital zoom simply can't stack up against the Canon S120's optical zoom. The Canon can not only zoom in further, it also retains detail and sharpness better when zoomed in to its full 5X power.

Photographers and photography websites like ours will continue to debate the pros and cons of smartphone versus camera, but for now there's simply no contest when it comes to zoom.