List of issues with the UleFone Armor 2 camera
Although being a device with high price-performance at release time (August 2017)[note 1], the UleFone Armor 2 has a low-tier and malfunctioning camera.
The phone has the following issues with its camera:
Camera hanging bug
After too much uptime (starting at 3 days, but occasionally might not even happen even 20 days of uptime), the camera viewfinder might randomly hang up seconds after launching the camera.
When exiting the camera, it might (in good case) start working normally after re-launching the camera, or (in bad case) an error message claims that connection to the camera is not possible because allegedly being accessed by another application. Android's integrated battery monitor claims the camera to be permanently active, and battery drain significantly increases in that state.
Shortly before this phenomenon occurs, video recording might not start, indicated by the timer being stuck at
⚫ 00:00, during which however capturing photos (at the same resolution as the video itself) is possible.
The likelihood of camera hanging appears to correlate with the number of camera launches, and appears to increase if launched from a double-press of the power button.
The technical reason for this issue is unknown. The only known way to evade that state is rebooting.
Front camera hanging
When requesting a video recording framerate on Open Camera above 30 fps, the smoother framerate will be visible in the camera viewfinder, but when hitting recording, the front camera crashes and becomes unresponsive until reboot, similar to the rear camera after too much uptime. The technical reason for this issue is unknown.
Poor camera controls
The camera software lacks the ability to lock autofocus or exposure, and continuous autofocus is disabled during video recording, forcing the user to repeatedly tap onto the screen to refocus. Additionally, the focus tends to reset to far when filming close subjects, with no ability to lock it. However, the third-party application OpenCamera is able to perform continuous autofocus and lock the focus.
While focussing, the camera options (such as the button to open the settings menu) are locked (grayed out). Due to the slow autofocus, inadvertently tapping next to that tiny button could cause camera settings to be inaccessible for up to five seconds, which is the autofocus duration in poor lighting.
The professional mode lacks manual focus and exposure controls, and settings are not reset when returning to plain Photo (automatic) mode. Furthermore, the camera software lacks an indicator warning the user when running out of space storage. In comparison, Samsung mobile phones show the estimatedly remaining photo count if 300 or less, and the estimatedly remaining video recording time if below one hour. Earlier Samsung phones such as the 2011 Galaxy S2 always showed it.
Hidden image pixel setting
The current megapixel setting is not permanently visible on the viewfinder.
If one earlier reduced the megapixel count to reduce consumption of space storage, but forgets to set it to a higher resolution for more important moments, one might accidentally capture those moments at a lower resolution.
Photo during focus
The device occasionally captures a photo while focussing, resulting in a blurred photo, which can be prevented by deactivating zero shutter lag mode.
Moov atom saving failure
Occasionally (~1 out of 100 videos), the camera software fails saving the video file properly, resulting in a corrupted moov atom, thus an unplayable video file.
No lossless digital zoom
At any video resolution, the camera offers up to 5× digital zoom. However, for video recording, the digital zoom is unable to use image sensor cropping.
Using digital zoom while recording at a lower resolution than 1080p (the highest resolution) is only lossless until the innermost crop of a 1080p resolution has been reached instead of the full 16 megapixel image sensor.
This means, for example, that digital zoom at 720p video resolution is only lossless up to ×1.5, rather than ~×4.1, which would have technically been possible given the image sensor.
However, the front camera is able to use its full resolution for lossless digital zoom, while, for instance, front camera zooming is missing on many Samsung mobile phones entirely, despite of technical possibility.
Lossless digital zoom with the full image sensor resolution is supported for photos. If Zero Shutter Lag mode is enabled, the image shown in the preview viewfinder is able to use the innermost area of the image sensor, while not if enabled.
Unsolicited burst shot
Occasionally, especially shortly after launching, the camera randomly enters burst mode. Releasing the camera button does not end the burst sequence.
The only way of ending the burst sequence is tapping the virtual camera shutter button or exiting the camera application.
Although the above-average burst shot performance (~10 full-resolution photos, limited to 99 photos), the burst mode is more often annoying than useful.
Three ways of preventing an unwanted launch of burst mode is enabling HDR mode or automatic scene detection (both of which, however, expectedly add shutter lag) or only using the volume keys for photography, not the dedicated physical shutter button or the virtual (on-screen) shutter button.
Burst mode is not supported on the front camera.
Low panorama resolution
Rather than using the 5376 pixels of height, the panorama mode of the UleFone Armor 2 only uses a height of around 1200 pixels when held vertically, and 848 pixels when held horizontally, making the feature nearly pointless, although better than nothing.
The only way to make somewhat useful panorama shots with the device is photographing inside the normal camera mode and stitching the individual photos together in a photo editing software.
Higher panorama resolutions may be supported by third-party (non-stock) camera software.
Purpose of zero shutter lag option
It appears that deactivating zero shutter lag increases the likelihood of in-focus (non-blurry) and non-shaky photos.
However, a side effect is that makes the ISO setting (which also affects exposure duration, despite the separate exposure value setting) is ineffective while zero shutter lag is deactivated, meaning that adjusting it makes no difference on the image.
No manual camera API
Despite of an Android version above 5.0 Lollipop, third-party software such as Open Camera are not able to access advanced camera controls such as manual exposure time setting. This could be a restriction of the abysmal S5K3P3 camera module.
Low-tier image sensor
The rear camera of the UleFone Armor 2 utilizes the Samsung S5K3P3 image sensor, which is a low-tier image sensor with a small pixel surface size that is intended for rather slim mobile phones[note 2], and not for an outdoor mobile phone that has space for a much larger image sensor.
Noise in the image at 100% zoomed view is visible when photographed at the lowest ISO setting of 34, in good lighting. The indicated ISO value might even be inaccurate. Even images produced by the front camera are visibly far less noisy than the rear camera at the lowest light sensitivity, and also has a solid 1080p video quality.
The competing Doogee S60 not only uses the vastly superior Sony IMX230 image sensor (also used in UleFone Power 5) with a larger surface size and higher resolution, but is also optically stabilized, which allows recording steady handheld video footage and prolonged handheld photography exposure times in low-light situations.
Reviews of other mobile phones such as the Doogee Mix, as well as comments under the same, confirm that the image sensor is problematic and abysmal.
When recording video onto a MicroSD card, the audio track contains a repeated half-second noise that repeats every few seconds.
More of this noise is hearable at higher video resolution settings due to the higher data rate, and also when recording audio using a voice recorder while another application is accessing (both reading and writing) the MicroSD card.
Photos during videos have no reoslution benefit
Photos captured during video recording have the same resolution as the video itself, making the feature technically redundant.
Some other mobile phones such as Samsung Galaxy flagship phones make significant use of the photo-during-video feature. The Galaxy S5, Note 4, S6 and Note 5 for example, capture full 16 Megapixel (5232×2988) still images during 1080p video recording.
The brightness of the LED flashlight during exposure is lower than the focus beforehand, while it should be at peak during that moment. This suggests yet another poor implementation.
- The camera uses a 5376×3456 multi-aspect-ratio image sensor with highest allowed resolutions of 4608×3456 and 5376×3024 for 4:3 and 16:9 respectively. No option for the highest actual image sensor resolution exists, possibly due to lens field-of-view exhaustion in the corner. As an example, the Nokia Lumia 1020 uses such an implementation as well.
- Although the precluded camera software lacks slow motion video recording, 120fps can be recorded at 480p using the Open Camera application.
- One benefit of the otherwise terrible camera of the UleFone Armor 2 is its low shutter lag (if zero shutter lag mode is enabled).
- Another benefit is the camera's wide field of view.
- The camera settings when launched from lock screen and when launched after unlocking are stored separately.
- Video recording is done with a variable frame rate between 10 and 30 frames per second, depending on lighting conditions, where darker surroundings demand longer exposure times and cause lower frame rates, enabling brighter videos in dark surroundings.
- The image quality in darkness might be somewhat acceptable if the camera is held very steadily.
- While the rear camera is active, fast charging (elevated voltage charging over MediaTek Pump Express) is deactivated. However, when manually supplying an elevated voltage (and with shorted USB data lanes to signify clearance for indefinite charging speeds), this does not apply. Also, the operation of the front camera does not affect fast charging.
- Issues unrelated to the camera.
- The fingerprint scanner becomes unfunctional after 16 days and ~10 hours of uptime. Technical reason unknown. Only solvable with rebooting.
- Charging speed (using MediaTek PumpExpress 1.0 or manually applied elevated voltage) is only 10 Watts, unlike the advertised 18 Watts.
- However, as already mentioned, usage of the device while charging is handled like all known laptop computers handle it: By drawing additional current from the power supply instead of subtracting or (even worse) throttling charging speed. The limit at any voltage up to 14 volts (highest supported input voltage) is 1.9 Ampère. This advantageous charging behaviour is one of the device's greatest benefits.
- Non-replaceable battery (although this sadly is a normality among mobile phones since circa 2015.)
- Active file transfers over USB-OTG might significantly slow down the system.
- The precluded file manager has a bug where it refuses to transfer files over to an ExFAT MicroSD card if the total selection is larger than 4 GB, despite ExFAT does not have a limitation of 4 GB per file, and the total selection consists of many smaller files.
- Holding the power button for 10 seconds causes a forced power-off, which may happen accidentally when the mobile phone is in a pocket or in a phone bag.
- The touch screen can detect up to five fingers simultaneously, but many applications such as an MupeN64 (Nintendo 64 emulator) only recognize two fingers, while many mobile phones have been supporting the recognition of up to ten simultaneous fingers for years with compatibility to the same applications.
- Launching the camera with the dedicated camera shutter button (that only has one level) requires holding it for five seconds, where one second would have been more suitable.
- However, a double-press of the power button is also able to launch the camera.
- The battery temperature sensor does not measure one digit behind decimal, which Samsung mobile phones have been capable of since around 2011. This could be useful to determine temperature changes faster.
- Out of the two speaker grills on the rear side, only the left one (when looked at from rear side) contains a speaker. The right side is just a dummy. However, the device's speaker is very loud and powerful.
- Other than the camera, the system performance and starting speeds of applications is good, and 6 GB of RAM is outstanding in that price range for a mobile phone unveiled in 2017.
- The device stays rather cool during fast charging, even during operation, regarding that it uses the superior spare current charging method.
- The device is able to play 1440p video smoothly, but not 2160p, despite having the same GPU as a Galaxy S7 (Mali T880) and the same CPU (Helio P25) as other mobile phones that are even able to record in 2160p, which requires more processing power than mere playback.
- The device is equipped with a large 4700 mAh battery, spare-current fast charging (usage of spare power supply current during screen-on instead of subtracting from charging current), a robust design, a bright 1080p screen, physical shutter button, water resistance and a high-quality front camera.
- The S5K3P3 image sensor unit is poorly documented. No public specification sheet of it exists.