The Apple iPhone 4S was announced last night, with one of the chief improvements being a better camera with better Back Side Illumination, wider aperture and an extra optical element. Leaving aside other elements of the iPhone 4S (which, interestingly, retained its 3.5″ screen), such as the Siri voice control, We thought you might be interested in a comment or three on the 4S’s camera, as it compares to some of Nokia’s camera phone units.
Primarily, its crucial light-gathering ability, by far the biggest factor when considering how a smartphone camera performs when the light is less than optimal (i.e. not sunny!)
|Device||Sensor size||F stop (max aperture)||Year||Raw Light gathering ability ‘quotient’||Light gathering ability (BSI-compensated)|
|Apple iPhone 4S||1/3.2″||2.4||2011||1.70||2.88|
|Samsung Galaxy S II||1/3.2″||2.2||2011||2.02||2.62|
|Sony Ericsson Xperia Arc||1/3.2″||2.4||2011||1.67||2.17|
|Nokia N82 (and N95)||1/2.5″||2.8||2007||2.04||2.04|
Apple’s keynote claim, that the Back Side Illumination means up to 70% more usable light reaching the CMOS sensor, is extravagant but possible. Essentially, BSI involves changing the position of the sensor’s wiring so that no unwanted reflections or obstructions mar the photon detection. With BSI compensation, you can see that the iPhone 4S’s camera could potentially produce better results in indifferent light than even the Galaxy S II – but it’s still some way short of the raw light gathering potential of the two year old N86 and far short of the one year old N8.
Add in the use of Carl Zeiss optics in the N8 and add in the Neutral Density filter (for handling bright sunny conditions and ensuring that too much light doesn’t get through to the sensor), and the N8 stays even further in the lead. Then add in the proper Xenon flash, almost unique these days to the Nokia N8, which takes care of indoor, low light situations (parties, events, meets, living rooms, clubs, etc) and, on the camera front at least, the N8 and iPhone 4S are still some way apart.Just in case you were wondering! You may also be puzzled that the N8 has a comparatively high ‘F’ number, meaning a smaller aperture, when compared to the newer Galaxy S II and iPhone 4S cameras. The latter two devices have deliberately larger apertures, again to try and capture more light to fall on their physically limited 1/3.2″ sensors. This is a valid approach but does have the disadvantage that there will be significantly less depth of field. Great for arty portraits and macro shots where you want everything blurred in the background, not so good for generic photos. Balancing F ‘stops’ and shutter speed has always been part of the art of traditional photography – it’s no surprise to see different manufacturers tinkering with a different balance/formula in smartphone camera technology.
via (All About Symbian)