Smart, Safe and Intelligent Zoom

Realizing that digital zoom is not really a good thing because it negatively affects image quality, camera manufacturers have introduced a new type of digital zoom variously called “Smart Zoom” (Sony), “Safe Zoom” (Canon) and “Intelligent Zoom” (Panasonic and others). Smart/Safe/Intelligent Zoom (let’s collectively called them Intelligent Zoom, or iZoom for short) can be viewed as an “ethical” digital zoom which avoids interpolating the image and so avoid degrading image quality. iZoom works only if you select an image size smaller than the full available image size. So, for example, if your digital camera is capable of producing a 12MP image, Smart Zoom is available only if you select to save your images as 7MP or less. In other words, with this particular type of digital zoom, the MP resolution decreases as you ‘zoom’ — in other words you are just cropping the center of the image (without enlarging and interpolating back to the original resolution).
Say, your digital camera is 12MP and you select to save your images as 10MP. So, in effect, you are forfeiting 2MP of image data (extracted from all over the image area) that the digital camera’s sensor has captured and now has to throw away [you hope the camera makes the right decision and does not throw away important image data]. Enter iZoom that says, “Hey, instead of throwing away 2MP of good data from all over the image area, why don’t I crop out all the pixels starting from the outside perimeter? When I’ve cropped out 2MP of image data all around, I have 10MP left over and that’s what you want, right?” Notice, the 10MP image does not have to be interpolated and enlarged back to 12MP as traditional digital zoom does (because you elected to save it as 10MP, remember?). So, in effect, you’ve basically more or less retained the same image quality but you have to save your resulting simulated zoomed image in a smaller image size. Of course, if now you turn around and enlarge it in post-processing, you will be limited to what a 10MP image can be enlarged up to without image degradation.
I call iZoom “ethical digital zoom” because it is not made available at full image size — this would cause image degradation. The smaller you elect to save your image, the more iZoom power you have available (folks, you’re basically just cropping the image without re-enlarging, which you can also do at any time in post-processing).
So, our recommendation still holds. If you want zoom power, only optical zoom matters! iZoom is the better form of digital zoom, but what you gain in simulated zoom power (again, you’re just cropping), you lose in image size. There’s no free lunch.
Again, don’t buy a digital camera based on digital (traditional or inteligent) zoom. Always compare optical zoom with optical zoom. If you are comparing 2 digital cameras with the same optical zoom, but one has intelligent digital zoom and the other has traditional digital zoom, then the intelligent zoom has a slight advantage. But personally, I wouldn’t even look at that because there are a lot more important features to differentiate the cameras.