Video Performance

Now that we’ve gotten a good idea for how the Galaxy S6’s camera performs in a range of situations for taking photos, we can turn our attention to video recording quality. Even if a camera performs well at taking images, video recording can often expose weaknesses in areas such as encode blocks in the ISP. In addition, it’s possible to see how well an OEM can handle post-processing on a real-time basis when each frame has to be done in around 16 to 32 ms rather than a single frame in a few hundred milliseconds. This also tends to level the playing field somewhat as an OEM can’t force longer frame exposure times without affecting frame rate in a very visible manner.

We’ll start with a relative static video to get a good idea for video quality without severe camera shake and with relatively fixed focus.

In the 1080p30 mode, Samsung has opted for H.264 high profile encoding with a bit rate of 17 Mbps. For 1080p30 video, this bitrate seems to be around where most OEMs are staying to balance image quality and file size.

Viewing the video shows that there isn’t any sort of distracting macroblocking going on or any of the usual artifacts. The field of view appears to cover most of the sensor as well which should help with improving detail and overall video quality if one doesn’t zoom in.

Interestingly enough, this video is already exhibiting a combination of oddly smooth and jerky pans that is likely due to hitting travel limits on the OIS. I suspect that this behavior is part of the reason why Apple didn’t enable OIS in video on the iPhone 6 Plus, as those that are unfamiliar with how the stabilization works would likely be frustrated by the effect.

The Galaxy S6 also records at 256 kbps, 48kHz two channel AAC audio, which is much higher than the 96-128 kbps rate that I’m used to seeing on most smartphones. The audio recorded definitely seems to be quite clear and crisp with no real distortion.

Moving on to the 1080p60 mode, we can see that Samsung is opting to go with the same video and audio encode settings, but at a 28 Mbps video bit rate to handle the higher frame rate. Subjectively it appears that this mode comes with a drop in video quality, which is a bit disappointing as 1080p60 shouldn’t come with any real compromises in image quality to fit with user expectations other than an increase in file size to deal with the higher frame rate. Other than this, motion is fluid and video remains of usable quality which is good.

For slow motion, Samsung opts to use a 48 Mbps video bit rate while keeping all other video and audio settings identical at a 720p resolution with a 120 fps frame rate. Unfortunately, Samsung seems to be running into either a self-imposed limit or some other limitation at the hardware level like camera output bandwidth, ISP processing limits, or encode block limits. The result is that slow motion video ends up looking more like 480p than 720p video.

On the other end of the spectrum, Samsung has included 4Kp30 support with a 48 Mbps video bit rate and identical video and audio encode settings as all of the other video settings. It seems that there aren’t any issues with quality here, which makes me wonder why there are issues when using the slow motion mode as the bit rate is similar while the number of pixels processed per second is higher. Video is amazingly high resolution here, but I’d still love to see a 4Kp60 mode as the logical next step with the use of HEVC encoding to also make for fluid motion. There’s also a 5 minute limit as with most phones that can record 4K video, presumably to avoid taking up excessive amounts of storage.

The final video test I did here is to simply test the stabilization, focus stability, and exposure accuracy of the Galaxy S6 by walking down a short path and attempting to switch between focusing on near and distant objects which are either strongly shadowed or well-lit in the scene. Here we can see that the sound quality of the video recording remains high in quality, but there are some advantages and disadvantages of the Galaxy S6 when comparing to the iPhone 6. The Galaxy S6 is clearly better-stabilized than the iPhone 6, but there’s a great deal of jerky movement in the video rather than a consistent shake due to the OIS hitting a travel limit and resetting.

It also appears that the auto focus isn’t sensitive enough to figure out what part of the scene I’m attempting to focus on, as it tends to avoid changing focus if possible. It’s a bit surprising in this case as Samsung’s IMX240 sensor also has PDAF, which means that it should be possible to cleanly focus in on the closest object within the center ninth of the frame. Samsung’s auto-exposure mechanism also attempts to keep the sky from blowing out at the end of the video, which causes almost everything else to end up quite dark compared to the iPhone 6.

Overall, in all of the videos and photos there’s also a consistent trend of Samsung favoring oversaturation of color which often isn’t accurate, but I suspect the average consumer will prefer such tuning. In general, the Galaxy S6’s camera is a solid step up from the Galaxy Note 4, and can even beat the iPhone 6 in some situations, but taking everything into account the camera is equal to the iPhone 6 Plus in quality at best as it trades blows in daytime and low light situations.

Although Samsung has drastically improved the speed of the camera, camera application, and the gallery application, they’re still fighting a fundamental sensitivity disadvantage by using 1.1 micron pixels. Given Samsung’s dominant position in the Android industry, I can’t help but wonder how much better things could be if they elected to go back up the pixel size scale.

At any rate, the only issue that Samsung really needs to fix at the moment is the obvious haloing around high-contrast detail in photos. The fact that I can do this sort of detailed comparison between the iPhone 6 and the Galaxy S6 should speak volumes about just how good this camera actually is, compared to any Galaxy phone before the Galaxy Note 4. When it comes to flagship Android phones, the Galaxy S6 has the best camera, and there’s really nothing else to be said.

Still Image Performance Software: TouchWiz UX
Comments Locked

306 Comments

View All Comments

  • akdj - Friday, April 24, 2015 - link

    That's NOT the same display. The Note 4 was a step up from 5Active and this is an even bigger step 'up' for AMOLED. The anomalies have been talked about in many reviews. As well as some purple fringing shooting low light (w/light source, like a candle). Killer display though!
  • Refuge - Friday, April 17, 2015 - link

    I'm not entirely sure, I kind wish he had elaborated more on it. Especially when this is a flagship phone and he says there is a defect with the perfect screen.

    But they only thing I can think of is how it seems to reflect much like a bubble would in direct sunlight. Maybe there is a risk of this rainbow effect screwing with color accuracy in direct sunlight? I'm not entirely sure either.
  • Ammaross - Friday, April 17, 2015 - link

    I see two vertical dark bars on left and right sides of the screen and one 1/4 from the top horizontally. Maybe that's what he's referring to...
  • Peichen - Saturday, April 18, 2015 - link

    I see the same thing as Ammaross. I guess some of you need to have your screen calibrated. I can see the dark bars on my home PC but I guess I won't be able to see it on the cheap/crap workstation at work.
  • Maxpower2727 - Friday, April 17, 2015 - link

    The only thing I saw in that photo was reflected light, which is to be expected with any phone and could hardly be considered a "defect." I really don't understand what he was getting at with that.
  • JoshHo - Friday, April 17, 2015 - link

    It was surprisingly hard to capture, but it's the photo of the horizontal/vertical bars when the display was under strong sunlight.
  • arayoflight - Friday, April 17, 2015 - link

    Josh, I think the front facing camera has a1/4.1" sensor, not 1/3". It was conformed by Samsung tomorrow.

    Also, the IMX240 has 1.2 micron pixels, not 1.12.

    Correct these 2 mistakes. The review was great though.
  • JoshHo - Friday, April 17, 2015 - link

    Apologies. I have fixed the FFC sensor size.

    To my knowledge the IMX240 uses 1.12 micron pixel size, going by Chipworks measurements and the released spec for the S5K2P2 sensor which has the same pixel count and sensor size.
  • arayoflight - Saturday, April 18, 2015 - link

    The s5k2p2 has 1.12 micron size. Also they're both 1/2.6" and identical resolution.

    But 1/2.6" necessarily doesn't mean they're same size. It just tells the size of the disk and hence there can be a difference.

    I think also on the Wiki page of IMX240 it's 1.2 micron. Though it's a different 4:3 IMX240 but I doubt they'll change the pixel pitch for a custom IMX240 used by Samsung.

    Just look into it. Even I want to know the perfect pixel size :)
  • will54 - Monday, April 20, 2015 - link

    Its the one horizontal stripe and the 2 vertical stripes on each side of the screen

Log in

Don't have an account? Sign up now