Samsung Galaxy S 2 (International) Review - The Best, Redefined
by Brian Klug & Anand Lal Shimpi on September 11, 2011 11:06 AM EST- Posted in
- Smartphones
- Samsung
- Galaxy S II
- Exynos
- Mobile
Behind SGS2's Camera - Still Quality
Now the next subject is still image capture on SGS2. Before I go any further, I think now is as good at time as any to talk about what sensors are in the device. Getting to the bottom of this took some poking around, and where I started was the camera firmware. Usually getting what sensors are used in a given device is pretty straightforward - look for driver messages in dmesg when the kernel boots, and then see which ones correspond to cameras. However, on SGS2 the thing is hidden behind a custom ISP that talks over I2C to Exynos, which didn’t lead me much further than just finding out what particular ISP is onboard.
I opened the camera firmware (from /system/etc/firmware ) in a hex editor and fired away. There are number of interesting things which pop up. First up is this:
Softune REALOS/FR is Realtime OS for FR Family, based on micro-ITRON COPYRIGHT(C) FUJITSU LIMITED 1994-1999
So we know that the ISP is Fujitsu. Then there’s a line like this:
Copyright (c) 2005-2008 by FotoNation. All rights reserved. Face Detection Library v.1.2.58.7
and finally:
OBED04 Fujitsu M5MOLS
all strewn among a bunch of padded bits and compiled code incorporated into the SGS2’s “camera” firmware. So what’s the real story? Well, SGS2 uses a Fujitsu Milbeaut M–5MO ISP paired with one of two cameras. To find out which camera SGS2 uses, I took a look in Francois’ SGS2 kernel repo under the actual M5MO C driver file. Inside, there’s a line like this inside a function named “m5mo_camera_type_show”:
if (state->exif.unique_id[1] == 'B') { strcpy(type, "SONY_IMX105PQ_M5MOLS"); } else if (state->exif.unique_id[1] == 'C') { strcpy(type, "SLSI_S5K3H2YX_M5MOLS"); } else { cam_warn("cannot find the matched camera type\n"); strcpy(type, "SONY_IMX105PQ_M5MOLS"); }
So we now know that inside SGS2 is either a Sony IMX105, or Samsung S5K3H2YX sensor. This is basically the same exact camera lottery situation that the MyTouch 4G Slide is in, as it in fact has the same two exact sensors listed, though F/2.2 optics. Both are basically the same on paper and should offer similar performance - 1/3.2“ size, 1.4µm backside illuminated pixels, and 8.13 MP (3264 x 2448). The front-facing camera uses a Samsung S5K5BAF 2 MP sensor sized 1/5” and with 1.75µm square pixels.
Interestingly enough, I believe I was able to find the actual module which Samsung uses inside the SGS2 on a Samsung fiber optics website, using the Sony IMX105 module. Take note of the appearance of this module, as it’s virtually identical to what I saw inside the device as I’ll show in a moment.
Having two sensor suppliers isn’t anything new, Apple has done it (and will continue to do so), HTC is doing it, and now Samsung is doing it too. With the same on-paper sensor performance and the same autofocus + optical system module, things should all work out and photos should look the same no matter what sensor is inside.
Other specs about the camera module are that EXIF reports an F/2.7 aperture and 4.0 mm focal length. This is a bit odd to me since F/2.8 is on the typical full-stop scale (2*sqrt(2)), and then F/2.4 is a next half-stop, and I’m only aware of IMX105 coming in F/2.4 and 2.8 modules. Just goes to show that sometimes EXIF data is weird. The module is most definitely the F/2.8, f=4.15 mm variant with a 28.1 degree horizontal field of view and 4 plastic aspheric lenses.
As an aside, if this whole system sounds familiar, it’s because the Sony IMX105 module with F/2.4 optics is the oft-rumored camera going into the next iPhone.
So that brings me to the infamous magenta circle issue which numerous people have reported seeing on their SGS2s. The last time we saw this was with the iPhone 4, where a green circle is readily apparent under certain light conditions or when photographing a homogenous color or texture. Some users have reported seeing a similar magenta circle on the SGS2 camera when photographing under similar conditions, so I set out to replicate it.
The closest I can get to the magenta circle
For better or worse, I can’t see the magenta circle on the SGS2 we were given, though I don’t doubt that some devices do show it. It doesn’t take much to extrapolate and come to the conclusion that is in part due to what’s becoming a CMOS lottery - now not only is there a display lottery (like what notebook buyers have been dealing with for a long time), but a CMOS lottery for sensors.
The magenta circle I see on this SGS2 is faint and nowhere near as pronounced as the green iPhone 4 circle, nor the SGS2-captured images I’ve seen online. Further, I haven’t been able to devise a method to tell which of the two possible sensors are inside this particular SGS2. I’ve taken some photos of completely white objects at a variety of focus positions and under different lighting conditions for your own perusal.
We’ve done the usual thing too and taken photos with the SGS2 inside our lightbox test scene, with the lights on and lights off. With the lights on, the SGS2 has a hard time nailing white balance with the test illuminated in auto mode, and in manual mode (set appropriately) it still has the wrong color temperature. This is just a bit unfortunate since otherwise sharpness is excellent, there’s little noise, and little to no chromatic fringing at the edges. I’m very impressed with camera performance here and would encourage viewing those images 1:1.
On the front facing camera, we get performance that looks actually surprisingly good. So good that it could actually pass for rear facing camera quality (resolution notwithstanding) of some previous generation devices.
With the lights out, the SGS2’s single LED flash illuminates the test scene nicely and gives good color temperature. SGS2 also does the right thing and fires up the LED for autofocus in the dark.
Next, we took photos with the SGS2 at the usual test locations, and it’s here that SGS2’s camera really shines. As a reminder, test locations 3, 4, 6, and 7 are the only ones remaining that I can visit, so skip 1, 2, and 5. SGS2 just really has great well-corrected sharpness and performance even out at the edges where aberrations take off, good colors without insane saturation, and great dynamic range.
Finally, I captured a large number of miscellaneous photos with the SGS2’s rear facing camera as well. I think in these real-world scenarios we get to see a better example of the SGS2’s camera performance, which is extremely good among the smartphones we’ve seen so far. Samsung also doesn’t make the mistake of putting the last vertex of the camera system behind a piece of plastic integrated into the battery cover. Instead, the module juts out through the battery cover in a way that doesn’t allow dirt and dust to collect.
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numberoneoppa - Wednesday, September 14, 2011 - link
Guys, that mysterious notch you write about is not for straps, it's for phone charms, and it's arguably my favourite feature of samsung phones. (In korea, phone charms can be used for more than just cute things, one can get a T-money card that will hang here, or an apartment key).Tishyn - Wednesday, September 14, 2011 - link
I spend hours every week just browsing through reviews and tests comparing devices and vendors. This is one if the most interesting and most comprehensive review I've read for a veery long time.I especially enjoyed the rendering part and how it relates to the ultra mobile device market. Thumbs up!
milli - Wednesday, September 14, 2011 - link
Brian / Anand, why are you so reluctant to test chips from this company? ZiiO tablets, sporting the ZMS-08, are available for a while now and i'm sure Creative would send you the new Jaguar3 tablet (ZMS-20) if you guys would ask for it.The ZMS-20 has 26 GFlops ... faster than anything you've tested till now. The ZMS-40 coming in Q4 doubles that number!
I'm an old school IT technician and I for one don't understand your lack of interest. The GPU's in these chips are based on technology that Creative acquired with the 3DLabs purchase.
rigel84 - Thursday, September 15, 2011 - link
Just a quick tip: You can take a screenshot by pressing the power and home button at the same time.If you double tap your home button it will bring the voice talk feature.
While watching video clips just press the power button to disable the touch sensitive buttons.
Swipe your finger to the left on contact name to send him a message
Swipe you finger to the right on the contact name to dial the contact.
To see all the tabs in the browser just pinch inside twice :)
If you experience random reboots when you drop it on the table, or if you are leaning towards things or running, then try to cut a piece of paper and put it under the battery. It happens because the battery shortly looses connection to the pins. If you check XDA you can see that many people has this problem, and I had it too. I was experiencing many random reboots whenever I had it in my pocket, but after I pit a piece of paper below the battery they all disappeared.
A few things...
- GPS is horrible if you ask me. Unless I download the data before with gps-status then it takes ages. Mostly 15-30 seconds with 2.3.3 (no idea if the radio got updated in the release)
- Kies AIR is HORRIBLE! It's on pair with realmedia's real player from 10 years ago. Crash on crash on crash and sluggish behavior.
- I don't know whether it's the phone or not, but I've been missing a lot of text messages after I got my Galaxy S2. I'm on the same net, but along with the poor GPS reception I'm suspectiong the phone :(
- There is a stupid 458 character limit on textmessages, and then they are auto-converted to an MMS message. There is a fixed mms.apk on XDA (requires root) or you can download something like Go SMS Pro (still free) on the market, which removes this stupid limit.
ph00ny - Thursday, September 15, 2011 - link
OddI haven't seen any posts about the battery disconnect issues and if you've been browsing the xda forum, probably saw my thread about dropping my phone on concrete twice...
As for Kies AIR, i've used it twice and my expectation was low to begin and it wasn't that bad. Some things were definitely slow but it's a good start
-GPS for me has always been solid. I even used it on multiple trips in less than ideal location, not a single glitch even with shoddy cell reception.
ciparis - Tuesday, September 27, 2011 - link
I've been using Sprint's SGS2 (Epic 4G) for less than a day, but already there are some annoying points which I'm surprised aren't mentioned in this review:1) The digitizer lags behind finger movement.
In the web browser, when your finger moves, there is a disconnected rubber-band effect before the screen catches up with your finger. This is visible in the browsing smoothness video as well, and it's very noticeable in actual use. Coming from an iPhone 4, it feels cheap and broken.
2) Back/Forward navigation often ignores the previous scroll point.
If you spend some amount of time reading a page you arrived at from a link (it seems to be about 10 seconds or so), hitting back doesn't take you back where you were previously reading from -- instead of returning you to the page position where the link was, it drops you at the top of the page. This makes real web usage tedious. On the Sprint, the timing seems to be related to when the 4G icon indicates sleep mode: hit back before the radio sleeps and you are returned to the right spot. In actual use, this rarely happens.
3) The browser resets the view to the top, even after you've started scrolling.
When loading a page, there's a point in which the page is visible and usable, but it's technically still loading (which can go on for quite a awhile, depending on the page). It's natural to start reading the page and scrolling down, but typically the phone will randomly jerk the scroll back up to the top of the page, sometimes several times before the page is done. This is unbelievably annoying.
I suppose expecting an Apple level of polish prior to release is unrealistic, but Samsung seems hell-bent on positioning themselves as an Apple-level alternative; even the power brick looks like they took the square Apple USB charger, colored it black, and slapped their logo on it. The point being, they're inviting direct comparison, and it's a comparison their software team isn't ready to deliver on -- certainly not out of the box.
ciparis - Tuesday, September 27, 2011 - link
How are you supposed to use this phone if the keyboard is covering up the text fields, there's no "next" button to get to the next field, you can't see what you're typing, and there's no button to make the keyboard go away?Case in point: go to Google News and click on Feedback at the bottom of the page. There's no scrolling room at the bottom, so the keyboard obscures the fields; I was unable to send feedback to Google that their news site was opening every link in a new bowser window on a mobile phone (...) despite my account having the preference for that set to "off", because I couldn't navigate the form fields.
mythun.chandra - Wednesday, September 28, 2011 - link
Just realized there are no numbers for the Adreno 220 in the GLBench 2.1 offscreen tests...?sam46 - Saturday, October 1, 2011 - link
brian,please tell me which one of these smartphones is the best.i wanna purchase one of them so,pls help me in deciding.b1cb01 - Wednesday, October 5, 2011 - link
I love the green wallpaper on the first page of the review, but I can't find it anywhere. Could someone point me to where I could find it?