From: PhotoRoy6@xxxxxxx
: Re: new camera 41megapixels in a phone
_http://forwardthinking.pcmag.com/show-reports/294650-how-nokia-s-41-megapix
el-smartphone-works_
(http://forwardthinking.pcmag.com/show-reports/294650-how-nokia-s-41-megapixel-smartphone-works)
wow indeed! but I have to crawl the numbers, forgive me.. I'm used to
surprise and derision directed at claims of high quality phone cams, having
bought and owned a 5Mp phone cam back in the days when 1.5Mp was the biggest
you could get in the Western market from Sony/Nokia/Others .. and I'm more
than used to scepticism at high quality images from phones. However some of
this just sounds odd to me and it wouldn't be the first time a manufacturer
obfuscated things to their advantage (I'd add that my phone cam used a Sony
digital camera sensor as opposed to the sensors designed for phones - and it
had a mechanical lens cover rather than a nasty chunk of glass in front of
the lens to protect it/degrade the image.. )
http://www.pcmag.com/article2/0,2817,2400773,00.asp
http://tinyurl.com/87n9h4u has some pretty crazy sounding explanations of
things..
"e.g. If a conventional digital camera set to ISO 100 uses a shutter speed
of 1/30th second,
the Nokia 808 PureView uses 1/180th second in the same lighting conditions."
and
"Less is more.
The simple structure of Nokia PureView Pro beats more complicated designs
hands down. ... Conventional designs need many
more lens elements to provide the zoom capability and correct aberrations,
but these interfere with
definition and/or light transmission. Our simple structure has enabled a
significant improvement in
manufacturing precision, and our lenses are produced with 10x greater
precision than SLR lenses."
(but they still put a chunk of ordinary glass in fron tof the lens to
protect it :(
nice to see a manufacturer include this little fact though (well, the last
bit about the nyquist theory :)
"oversampling eliminates Bayer pattern problems. For example, conventional
8MPix sensors include only
4Mpix green, 2Mpix red and 2Mpix blue pixels, which are interpolated to
8Mpix R, G, B image. With pixel
oversampling, all pixels become true R, G, and B pixels. What's more, based
on Nyqvist theorem, you
actually need oversampling for good performance. For example, audio needs to
be sampled at 44 kHz
to get good 22 kHz quality."
now the numbers from Nokia
the claimed specifications:
Carl Zeiss Optics
Focal length: 8.02mm
35mm equivalent focal length: 26mm, 16:9 |
28mm, 4:3
F-number: f/2.4
Focus range: 15cm - Infinity (throughout the zoom range)
Construction:
· 5 elements, 1 group.All lens surfaces are aspherical
· One high-index, low-dispersion glass mould lens
· Mechanical shutter with neutral density filter
. Optical format: 1/1.2"
. Total number of pixels: 7728 x 5368
. Pixel Size: 1.4 microns
they also go on to say "For example, with the default setting of 5Mpix (3072
x 1728), once the area of the sensor reaches
3072 x 1728, you've hit the zoom limit. This means the zoom is always true
to the image you want." - uh huh..
This is a small sensor, but not as small as many other phones use - that's
nice :)
they claim a 41Mp image from 7728 x 5269 pixels, but then they talk of a
limit of 3072x1728 pixels..
It uses a digital zoom.
te sensor is about 10mm x 12mm based on my calculations
Then I find:
http://www.phonearena.com/news/Just-how-big-is-the-sensor-on-the-Nokia-808-PureView_id27515
which shows the actual sensor - which certainly is small
and
http://www.dpreview.com/news/2012/02/27/Nokia-808-PureView-with-41MP-sensor
which is basically a rehash of the manufacturers blurb.
I'd like to know a lot more about this sensor. the example images look
quite good tho
