Understanding Camera Optics & Smartphone Camera Trends, A Presentation by Brian Klug
by Brian Klug on February 22, 2013 5:04 PM EST- Posted in
- Smartphones
- camera
- Android
- Mobile
Trends in Smartphone Cameras
Recently, I became annoyed with the way Dropbox camera upload just dumps images with no organization into the “/Camera Uploads” folder, and set out to organize things. I have auto upload enabled for basically all the smartphones I get sampled or use on a daily basis, and this became a problem with all the sample photos and screenshots I take and want to use. I wrote a python script to parse EXIF data, then sort the images into appropriate camera make and model folders to organize things. An aberration of having this script put together was easy statistical analysis of the over four thousand images I’ve captured on smartphones from both rear and front facing cameras, and I was curious about just how much storage space the megapixel race is costing us. In addition I was curious about whether there’s much of a trend among certain OEMs and the compression settings they choose for their cameras. The plot shows a number of interesting groupings, and without even doing a regression we can see that indeed storage space is unsurprisingly being consumed more by larger images, with the 13 MP cameras already consuming close to 5 MB or more per image.
If we sort them into bins we can see that most really end up between a few KB in size to 6 MB, with the panoramas and other large stitched composites providing a long tail out to 16 MB or more.
The conclusion for the broader industry trend is that smartphones are or are poised to begin displacing the role of a traditional point and shoot camera. The truth is that certain OEMs who already have a point and shoot business can easily port some of their engineering expertise to making smartphone cameras better, those without any previous business are at a disadvantage, at least initially. In addition we see that experiences and features are still highly volatile, there’s real innovation happening on the smartphone side.
Facebook
Twitter
RSS
60 Comments
View All Comments
ltcommanderdata - Saturday, February 23, 2013 - link
http://www.sony.net/SonyInfo/News/Press/201208/12-...Sony's new Exmor RS sensors use a stacked structure which places the circuit section underneath the pixel section instead of beside it which should free up more room for more pixels or larger pixels within a given sensor module area or enable smaller modules. They also add a dedicated white channel for a RGBW coding which they claim improves low light performance. Any comment on the efficacy of these techniques?
Apple has been using Sony image sensors for both the iPhone 4S and iPhone 5 so that new Sony IMX135 with 13.13MP, 1/3.06", 1.12 μm pixel sensor looks like a prime candidate for the iPhone 5S.
slatanek - Saturday, February 23, 2013 - link
Well done, Brian. At last someone trying to explain and stress how much more is there to tiny smartphone cameras than just the megapixels. A few years ago I felt like we got over it and the race was over, but now few years later the race just continues but in the smartphone realm (previously compact cameras had the same issues where ultimate picture quality was compromised just to get to a higher number of megapixels on the box). Hopefully this will change in near future, but somehow I'm afraid that were stuck with it just as with the horrible quality displays in notebooks. And it's not that people don't want good quality, it's just that the behemot companys are not willing to take the risk.Anyways, thanks for a good read.
Shftup - Saturday, February 23, 2013 - link
Brain - Well done!This is a fanatastic article. Its well written, relatively easy to understand for any layman, and most importantly makes the reader coming back for more.
jabber - Saturday, February 23, 2013 - link
....for a smartphone to give me as good a picture quality as I got from my 3.2MP Nikon from 2004.When I find one I'll be happy.
I think a lot of the phone companies need to start poaching the optics and software specialists from the camera companies. It's all very well looking at the spec lists for components but its another thing entirely to make them all work together to produce a decent picture.
In the past for me near decent cams have been ruined by over zealous compression settings (Palm Pre2) or what appears to be zero configuration of the imaging processors (Nexus4).
No one yet has tweaked every part of the chain to provide a truly viable alternative to taking a $250+ camera along instead.
Never had anything to do with megapixels IMO. It's other factors that let them down.
I reckon in another 2 years we'll have it pretty much there.
MrSpadge - Sunday, February 24, 2013 - link
Same here, my Sony DSC-W5 from 2005 or so is still way better than my smartphone. If I could get at least similar quality in a new phone that would easily make it worth 50 - 100€ more for me.Tarwin - Saturday, February 23, 2013 - link
I enjoyed the article, it cleared up some doubts I had and taught me a few new things.In light of this article I hope you go into more detail in the One review when you eventually do it. I assume you will give special attention to the c amera due to how it goes against the trend and HTC's focus on it but I also hope you mention how it fits into all this a bit for those of us who read both articles. Thanks again.
DominicG - Saturday, February 23, 2013 - link
Hi Brian,much enjoyed your intro to camera optics. However you state:
"If we look at the airy disk diameter formed from a perfect diffraction limited ... we get a spot size around 3.0 microns"
You mentioned this is a back illuminated chip so that the light is focussing in a medium of refractive index ~3.5. Therefore the wavelength of red light inside the medium is ~700/3.5 = 200nm - still much smaller than the pixel. It is a bit more complicated than this since the optical resolution is of course determined not only by the wavelength but also the numerical aperture (NA) - the light refracts at the air-silicon interface so that a beam in air at 37 deg (2omega =75deg - your example lens), becomes a beam in silicon of only 10 deg. 10 deg in silicon gives a theoretical resolution (Rayleigh condition) of 0.7microns. Anyway, did you take all these factors into account?
fokka - Sunday, February 24, 2013 - link
thanks for this insightful article, brian, that's the sort of read i i visit this site for regularly!i have to say that i expected a little more (side-) content, though, like a more thorough look at the htc one initially pictured, one of the two reasons i clicked on the article. also a comparison with nokias pureview-approach would've been nice, since it's on the complete other side of the spectrum.
but this is just to nitpick, as i enjoyed the read none the less.
StormyParis - Sunday, February 24, 2013 - link
Great articleStormyParis - Sunday, February 24, 2013 - link
Seeing the interest everyone has in good pictures, and the relatively small size and cost of the lens apparatus, wouldn't it make sense to have 2 distinct cameras on a smartphone, and coordinate them to get better image quality ?