Camera Architecture

This go around, HTC put a 13 megapixel camera into the One mini 2. This in a vacuum wouldn’t be anything out of the ordinary, but in the context of the past year it’s well worth examining. After all, HTC kept the same ST VD6869 sensor across the One (M7) and One mini, and also continued to use a similar 4 megapixel camera in the form of the OV4688. Especially in light of all the rhetoric that HTC has pushed in favor of larger pixel sizes in marketing literature, it’s worth examining the camera of the One mini 2 closely.

HTC One Cameras
  HTC One mini 2 HTC One (M8)
Front Camera 5.0MP 5.0MP
Front Camera - Sensor S5K5E2
(1.12µm, 1/5")
(1.12µm, 1/5")
Front Camera - Focal Length 2.79mm 1.83mm
Front Camera - Max Aperture F/2.8 F/2.0
Rear Camera - Sensor OV13850
(1.12 µm, 1/3.06")
(2.0 µm, 1/3")
Rear Camera - Focal Length 3.82mm (28mm eff) 3.82mm (28mm eff)
Rear Camera - Max Aperture F/2.2 F/2.0
Secondary Rear Camera - Sensor - OV2722
(1.4µm, 1/5.8")

As can be seen in the table above, the same front facing camera sensor is shared by both the One mini 2 and One (M8), which is a Samsung sensor with 1.12 micron pixel size although the optical stack changes to reduce aperture size and increase focal length. The rear sensor on the One mini 2 is still an OmniVision design win, but the sensor model is the OV13850 as opposed OV4688 on the One (M8) and later production runs of the One (M7). While the sensor size is the same, as is the optics’ focal length, the differences end there as the One mini 2 has a smaller aperture at F/2.2, which is a quarter stop smaller, which means that light collection goes down as well. The lack of the second depth sensing camera also means that all of the Duocam effects such as UFocus are gone as well, which means that the One mini 2’s editing features are equivalent to the One (M7)’s.

Outside of hardware, the change in ISP is far-reaching in its effects. Zoe, Pan 360, and Dual Capture are all gone, which suggests that the ISP in the MSM8x26 series cannot support dual encode features the way that the ISP in the MSM8x74 series can. Video encoding is also severely limited as the One mini 2 only supports a maximum of 720p60 or 1080p30. This is clearly not a limitation of the camera sensor as casual examination of the OV13850’s data sheet shows that it can record data from the entire sensor at 30fps. This means that the encode blocks don’t support the necessary bandwidth for such features. It's also interesting to see that HTC has capped the maximum shutter speed in the camera to two seconds rather than four seconds in the One (M8).

In addition to these issues, the shooting experience is noticeably worse. Preview resolution and frame rate are worse than the One (M8), and it seems that autofocus speed drops as well. Shot to shot latency and burst shot capture rate both are much slower, and I suspect that this is either the product of worse random read and write speeds on the NAND or a bottleneck at the ISP. Overall then, this means that comparing the performance of the One (M8) and One mini 2 in camera will be difficult as they can be confounding factors upon camera image quality.

Introduction & Hardware Still Image Analysis: Spatial Resolution & Color Reproduction


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  • devione - Monday, May 26, 2014 - link

    Why, oh why, can't more manufacturers follow the Sony Z1 Compact route.. Reply
  • Johnmcl7 - Monday, May 26, 2014 - link

    I'd be interested to see the sales figures for the Z1 Compact in Europe where the phone is widely available to see if Sony's strategy of producing a flagship phone with a smaller screen has worked out for them. On paper the phone looks pretty much exactly what everyone has been wanting for a while in Android with a top end SoC, camera, micro SD, decent screen even weather sealing and without much compromise either as the price is reasonable as is the batterylife. It makes a complete mockery of the HTC Mini 2 as they both appear to be a similar price despite the Sony being a much more capable device.

    Yet I've not seen anyone with a Z1 Compact despite plenty of other Android phones and I've hardly seen any second hand for sale (I want a cheap one for going out cycling) whereas there's quite a few S5's around even though it's only recently released. I realise none of that's statistically relevant hence I'd like to see the sales data.

    I do think Sony were too slow releasing the Z1 Compact, I think if they'd released it around two years after the Galaxy S2 they'd have been in the perfect position to catch those who wanted a similar sized phone with top end specs. I knew quite a few people who had S2's and didn't want an S4 due to the increase in size however as there wasn't anything suitable in a smaller form factor with Android they went with the S4 and find the size is fine.

    A few friends and family have 'mini' phones particularly the S3 Mini and S4 Mini but they didn't just want a smaller phone they also wanted a cheap phone so wouldn't have considered a Z1 Compact if available.
  • Laxaa - Monday, May 26, 2014 - link

    My brother just bought the Z1 Compact, and it's an impressive piece of kit. I only wish it had OIS and a better camera app(like Nokia Camera on the Lumias) Reply
  • Death666Angel - Monday, May 26, 2014 - link

    From the article: "HTC then proceeded to launch the One mini, a phone that was the size that everyone had been asking for"
    From Johnmcl7: " On paper the phone looks pretty much exactly what everyone has been wanting for a while in Android".
    Really? Everyone wanted a phone like that? I didn't. I was fine with 4.3" in my SGS2 when the iPhone established the 3.x" form factor. I liked my 4.65" Galaxy Nexus when that was becoming the norm and I like the 5.2" LG G2 which is doesn't feel much larger than the GN. So count me out of that "everyone" group, please. Not everyone is looking for smaller flag ship phones, just like not everyone is looking for microSD card slots, replaceable batteries or phones made out of aluminum. Some are, others aren't. I'm someone who is fine with lugging around his Nexus 7 when I'm wearing a jacket. The 5.2" G2 fits perfectly fine in all my trousers and I have never thought "bly me, that size is really bothering me".
  • Johnmcl7 - Monday, May 26, 2014 - link

    OK, wrong turn of speech - my own phone is a Sony Z Ultra (6.4in screen) so I certainly appreciate the benefits of a larger screen. Reply
  • fokka - Wednesday, May 28, 2014 - link

    i'm really happy for you and you're right, not "everyone" wants all those things you list. the problem is that for people who are happy with 5"+ phones there already are many options - the whole flagship-segment caters to them.

    but for those who want all the power in a slightly smaller form factor there is exactly one viable offering - not much considered the dozens/hundreds of models on the market. and even this lonely smartphone will be "obsolete" in a matter of months, considering the specs of current and coming flagships.

    in a market like this, i think it's clear and also warranted, that people are complaining. but even if we aren't "everybody", it's still important that we voice our opinions. sorry if you felt collateralized ;)
  • sfuzzz - Monday, May 26, 2014 - link

    I feel exactly the same. Z1 Compact is a great phone (with some flaws like other) and the right size for everyday life, you don't have to carry a bag or a jacket only for your phone. I own a Nexus 5, coming from a Xperia U (perfect size for me) and this summer will see if i go mad feeling it in my pockets all day. As for the sales (of Z1 compact) It's difficult to tell the real figures, here in Italy is available for 450/420 euros or less, but anything that is not Samsung or iPhone is a "niche" phone. I own a N5, my sister owns a Moto G, and we are considered some kind of "geeks" only for that :) Reply
  • Gich - Monday, May 26, 2014 - link

    4xCortex-A7 can't keep up with 2xKrait 200 on benchmarks that do stress all core... and it should be worst on "normal" apps.
    Isn't this... very bad?
  • Gich - Monday, May 26, 2014 - link

    Also "it’s not much of an improvement"? I feel is more of a step back. Reply
  • tipoo - Monday, May 26, 2014 - link

    Yeah, I'd take dual krait over any number of A7 cores any day. Reply

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