Ulefone Gemini Review

19 March, 2017, 09:38:50

It's been all about dual rear cameras and bezelless screens (in various sorts of ways) in the smartphone market lately. Last year, Ulefone made an attempt for a smartphone with a bezelless display that was not bad - the Ulefone Future. This year, the company's response to the dual rear camera hype is the Ulefone Gemini. It sports mid-range specs and a price tag that's around USD 130, which makes it even more attractive. This review of the device is for everyone who is curious to see how a very affordable smartphone with two rear cameras performs on all fronts.
The review unit has been provided by GearBest.com


Ulefone Gemini sports a 5.5-inch display with an IPS LTPS display from Sharp and a 1080p resolution. It has a peak brightness of 520 cd/m2 and covers 96% of the NTSC color space. Protection of the display is ensured by a 2.5D curved Corning Gorilla Glass 3. The screen graces an all-metal body with classic Ulefone design. Its performance relies on a MediaTek MT6737T chipset that features a 1.5GHz quad-core Cortex-A53 CPU and a 600MHz dual-core ARM Mali-T720 MP2 GPU. They are combined with 3GB of RAM - LPDDR3, single-channel, clocked at 640MHz. The internal storage measures 32GB, expandable with up to 256GB. A 3-axis gyroscope, proximity, accelerometer and light sensor are on board as well. The model is equipped with a fingerprint sensor embedded in the home button. The latter works both as a capacitive and a physical key. The camera department of the Gemini packs two rear shooters. The first is equipped with a 13-megapixel Panasonic MN34152 SmartFSI sensor, while the second has a 0.3-megapixel GalaxyCore GC030A one, interpolated to 5 megapixels. Both have 5-element lenses. The two cameras work together only, the second providing additional depth of field. The front-facing shooter packs a 5-megapixel GalaxyCore GC5005 sensor as well, interpolated to 8 megapixels, too. The device draws its juice from a 3250 mAh Li-Pol battery from Sony. It supports MediaTek's Pump Express Plus (PE+) fast charging technology and has a Super Saving mode. The accumulator is said to provide up to 15 hours of talk time and up to 320 hours of standby time. The device works with the following network bands: 2G GSM - 850, 900, 1800, 1900 MHz; 3G W-CDMA 900 and 2100 MHz; 4G LTE - 800, 900, 1800, 2100, and 2600 MHz. 4G connections are with Cat. 4 speeds. The rest of the connectivity options of the model include dual-band Wi-Fi 802.11 a/b/g/n, Wi-Fi Hotspot, Bluetooth 4.0. The device supports GPS, A-GPS, GLONASS and has a micro-USB 2.0 port. It runs Android 6.0 Marshmallow, which is bound to be updated to Android 7.0 Nougat. Here you can check out all detailed Ulefone Gemini specifications.

What's in the box

Ulefone Germini is inside a simple cardboard box with a white lid that has the brand and model along with a photo of the device on it. Some information about the specifications is placed on a sticker on one side of the lid and on the bottom of the box. Inside, everything is carefully packaged. Besides the standard protective stickers for the front and back, the device has a pre-applied screen protector. It is placed on the top level compartment. Below it, there are a second screen protector and a transparent silicon case, each in a separate packagе, a charging adapter, USB cable, SIM tray pin, user manual. A phone holder is included as well.

Design, build and controls

Ulefone Gemini has an all-metal body made of magnesium-aluminum alloy crafted with the CNC process for precision. More specifically, the backplate has undergone punch pressing, CNC cutting, and laser engraving. The finish depends on the color of the device. For the black variant grit blasting is used that creates a delicate matte finish. The grey and gold color variants of the model have a more classic brushed finish. We are reviewing a grey unit. It has a slightly purple-ish hue that is visible only when the light reflects from the surface at specific angles. Indeed, this is a nice design touch. The only parts of the body that are not metal are the caps for the antenna areas. They are made of hard plastic with a dotted texture. The one of the lower antenna fits the body perfectly, but the one of the upper antenna area tends to protrude very slightly from the otherwise smooth surface of the back plate. This is because the vertical sides of the back are curved, while the cover of the antenna area has not been curved to follow their outline. This is just a minor detail that most people would overlook. The rear edges are chamfered, while at the front the frame tightly surrounds the plastic casing of the display. The overall shape and feel is that of a typical Ulefone smartphone.
The Gemini measures 9.1 mm in depth and weighs 185 grams, which actually makes it one of the thickest and heaviest smartphones in this size class - 5.5-inch display and a 3200+ mAh battery. However, it is worth stressing that it does feel much lighter and slimmer than it is. The height (154.5 mm) and width (76.8 mm) are average for a device of that size class. As long as it concerns the build, with every following device Ulefone demonstrates consistency in making well-built, reliable smartphones with no-frills design. All ports are perfectly crafted. The buttons have the right travel. They are tactile, without protruding too much from the frame and do not wobble. The smart button on the right hand side has a different finish, so it is easily noticed. The home button is solid and responsive, which is a challenge for a key that has physical and capacitive functions. It has an embedded fingerprint sensor. The latter can store up to five fingerprint IDs and may perform a number of additional functions, including application locking. One thing must be noticed, though. If you want to unlock the device when the display is off, you have to both touch and press the button, in order to do it. Unlocking with a touch only happens when the screen is awake, otherwise it does not work.
For the Gemini, Ulefone has chosen a slightly different controls layout. The volume and power buttons are placed on the left frame, while the hybrid, dual-SIM tray is located on the right frame and the smart button is below it. It serves as a shortcut to the Camera app. On the top frame you'll see a 3.5 mm jack, while on the bottom a single speaker grille, micro-USB 2.0 port and a mic hole are located. On the front above the display, from left to right, there are the light and proximity sensor, earpiece, and front camera. No LED notification light. Below the display there's the home button with an embedded fingerprint sensor, which can be used as a physical and a capacitive one. The Navigation bar is on-screen only and its settings allow you to choose the keys arrangement, whether the Task Manager should be replaced by the Menu, whether the bar should be hidden or not. However, if you opt out from the on-screen navigation bar entirely, it is a bit tricky to find your way around. You must have a fingerprint ID, which has to be associated with a back/home function from the Fingerprint settings. With the back function settled, you must know that pressing the home button leads you to the home screen/desktop and a long press on it opens the Task Manager. There are also off-screen and air gestures, which might turn out helpful in this regard, too. On the back of the device the two camera modules are placed one on top of the other with a horizontally placed, dual-tone LED flash between them. Along this central vertical "line" the Ulefone logo is imprinted below the two shooters.


Ulefone Gemini is equipped with a 5.5-inch IPS display made by Sharp with an FHD resolution (1080 x 1920) that results in a pixel density of 401 ppi. The panel is LTPS (Low Temperature PolySilicon). In previous reviews we have explained in detail that LTPS panels are used largely in screens with larger resolutions and pixel densities. This technology offers significantly higher carrier mobility compared to the amorphous silicone one. Thus, the sheer size of the unit can be reduced, power consumption is reduced, too, while brightness is increased. The monolithic integration of various circuit elements leads to creating thinner panels and drastically reduces production costs. The display of Ulefone Gemini is said to have a peak brightness of 520 cd/m2 and to cover 96% of the NTSC color space. It is protected by a Corning Gorilla Glass 3 and the top layer is 2.5D curved glass. The only software features that support the display are the Picture Mode and Dynamic Contrast from the MiraVision suite. Our review unit of the model demonstrated a good peak brightness of around 450 cd/m2. Interestingly, at 75% brightness level it maintains a high value of around 440 cd/m2 and at 50% brightness the white value measures 308 cd/m2. It is only at that point that the brightness drops more significantly and at 0% level, the white value is 24.61 cd/m2, which, however, is a bit higher than general. All this means that, though it might not be perfect for reading in broad daylight, the display is very bright. At the same time, black values are quite low, which results in a very high static contrast ratio of around 2000:1, which is impressive for a device of that class. It is only at the lowest brightness level that the static contrast ratio drops to 1000:1. This would be a perfect screen, if it didn't have a high white point temperature that makes colors look colder. The values at all brightness levels are maintained relatively the same - 10500 K.
Brightness White luminance Black luminance Contrast Color temperature
100 % 451.148 cd/m2 0.226 cd/m2 1996 : 1 10433 K
75 % 439.961 cd/m2 0.221 cd/m2 1991 : 1 10477 K
50 % 308.482 cd/m2 0.150 cd/m2 2057 : 1 10425 K
25 % 171.45 cd/m2 0.079 cd/m2 2170 : 1 10522 K
0 % 24.61 cd/m2 0.024 cd/m2 1025 : 1 10753 K
Another thing that strikes from a first glance is that according to the specifications, the display should cover 96% of the NTSC color space, however, the panel of our review unit barely even covers 100% of the sRGB gamut. More precisely, it achieves almost perfect coverage of the blues, but does not cover in full the green and red spectrum of colors. The panel has a traditional striped sub-pixel architecture. Viewing angles are not perfect and the corresponding photo below clearly demonstrates that both from vertical and horizontal lateral view there is a significant loss in brightness. To be honest, only very few displays show little loss in brightness or none at all from lateral view.

OS, UI and software

Usually Ulefone uses an almost stock Android with no bloatware for their smartphones and the Gemini is no exception. The lock screen contains shortcuts to the Voice Search and Camera app. Notifications are displayed on it by default. Swiping on it, lands you on the home screen where you see a docked row of apps and the four most used apps above it. Swiping to the left, leads you to the list with the rest of the applications. Pressing and holding the home button opens the Task Manager. A swipe down from the top of the home screen brings up the Notifications and a second swipe opens the Quick Settings. From here you can access the Users menu and activate the System UI Tuner. The Volume shade is classic, so is the Power off one, but with one difference - it contains a Super saver power mode. When you enter this mode, you get access only to the Dialer, Messenger, Contacts, and Clock. The Widgets menu is a typical Ulefone one. Starts with a choice of wallpapers and widgets and continues with a choice of screen transition styles (the round button), followed by themes and icon arrangement styles.
The Settings menu is traditional and simple. It has the usual four main groups of options - Wireless & networks, Device, Personal and System. The first group is where you manage your networks, data, SIM cards and wireless connections via Wi-Fi and Bluetooth. There are also Turbo download and HotKnot options. The Device group starts off with the Display settings, which don't offer anything advanced. Even the MiraVision suite contains only an image mode and dynamic contrast option only. The same is with the Sound & notifications and the Apps management. The Personal group contains the standard Location, Security with Smart Lock, Accounts, Google, Language & input, Backup & reset options.
However, due to the more advanced functions of the fingerprint sensor, there is a whole new Fingerprint settings group. It includes a Fingerprint Manager, which allows you to add, delete and rename IDs (up to five), associate a specific app to be locked/unlocked with a fingerprint ID. In addition, there are toggles for various functions associated with specific actions with the fingerprint. By selecting specific toggles for a simple tap or a tap and hold, you can answer calls, take photos while in the camera app, return home/back, navigate and play files in the music/video player, etc. System is the last major settings group. It features the usual Date & time, Accessibility, Printing, About phone, and if you have activated it - the System UI tuner. In this group, Ulefone has added a Smart Accessibility menu from where you can personalize the navigation bar, schedule power on & off, and toggle non-touch operations (air gestures), smart waking of apps by drawing a letter on the screen when it is off, etc. At the time of our review there have not been updates for the Ulefone Gemini. On March 10th, the manufacturer announced there will be an Android 7.0 Nougat preview for the model in April.
Ulefone Gemini has all the basic default apps you'd expect in a smartphone. They are installed directly on the home screen and the successive ones, which are accessed by swiping. Removing an app from there directly uninstalls it after a confirmation dialog. No app tray. You get the usual Dialer, Contacts, Messenger, Browser, Calculator, Clock, Radio, Sound Recorder, Downloads, File Manager, Music, Camera, and Gallery apps. From Google's services there are the Calendar, Drive, Gmail, Maps, Voice Search. That's it. Simple and no bloatware at all.

Networks, calls and connectivity

Ulefone Gemini has a hybrid, dual-SIM tray. One of the trays is for a micro-SIM card, while the other can house either a nano-SIM card or a microSD card. The model works with the following network bands: 2G GSM - 850, 900, 1800, 1900 MHz; 3G W-CDMA 900 and 2100 MHz; 4G LTE - 800, 900, 1800, 2100, and 2600 MHz. 4G connections are with Cat. 4 speeds. Call quality has been very good at all times. The model supports dual-band Wi-Fi 802.11 a/b/g/n, Wi-Fi Direct, Wi-Fi Hotspot, and Bluetooth 4.0. All these functions work fine as well as the HotKnot, which is MediaTek's answer to Qualcomm's NFC. The Turbo download feature is on board as well in case you want to download faster files that are larger than 20MB. The device supports GPS, A-GPS, GLONASS and has a micro-USB 2.0 port. Regarding satellite positioning systems, it managed to detect satellites from both quickly and with an excellent accuracy of up to 3 meters.


Ulefone Gemini's hardware is based on a MediaTek MT6737T system-on-chip. This 64-bit chipset, manufactured in a 28 nm process is an upgraded modification of the MT6737. The latter has four Cortex-A53 cores clocked at 1.35GHz, while the T version of the SoC has the same quad-core CPU, but clocked at 1.5GHz. Graphics are handled by a 600MHz dual-core ARM Mali-T720 MP2 GPU. It has a Cat.4 LTE modem with CDMA2000 built-in along with a video de-/encoder for FHD videos at 30 fps. Another smartphone, which we have reviewed and that packs the same chipset is the Oukitel U20 Plus. Ulefone Gemini scored 40183 points in AnTuTu, which is on par with the U20 Plus' result.
Actually, the picture is the same with all other tests we ran. Ulefone Gemini and Oukitel U20 Plus score pretty close not only in AnTuTu, Geekbench 4, and Vellamo, but also in GFX, Sling Shot, Ice Storm, Epic Citadel and PCMark's Work 2.0. The MediaTek MT6737T chipset is ideal for browsing and normal applications, but struggles with heavy apps and graphics. You will enjoy fluent gameplay with most of the games available on the market, but those requiring more graphics processing power won't be handled right by the entry-level Mali-T720 MP2 GPU, so you have to play them at their low or medium resolution/quality.
Ulefone Gemini is equipped with 3GB of RAM. It is of the older LPDDR3 generation, single-channel, clocked at 640MHz. The random-access memory is generous enough, and while it is not of the latest generation, it does its job. Even with many apps open in the background, the device does not lag. The built-in memory measures 32GB and of those 24GB are available to the user. In case you need more storage, you can use a microSD/TFT card with a capacity of up to 256GB. The Androbench and PCMark Storage scores show reading and writing speeds from/to the memory, that point to an eMMC 5.0 type of memory, but there's no official information about that. As long as it concerns the sensors, on board the mobile there are a 3-axis gyroscope (making the device VR-ready), accelerometer, light and proximity sensor, magnetometer, etc. As already mentioned earlier, there's a fingerprint sensor embedded in the home button that has many functions besides simple unlocking. They've been explained in the Fingerprint settings text above. Here it is worth mentioning that the sensor is very fast and responsive, indeed. You should bear in mind that it is a passive one - in order to unlock simply with a touch, the screen must be awake. If you want to unlock the device with the screen off, you have to both touch and press the button. The latter wakes up the screen.


As long as it concerns the camera department, Ulefone Gemini has a direct competitor in the face of the Oukitel U20 Plus. Both smartphones, even have almost identical Camera apps. They have a traditional layout with a big shutter button and several modes appearing above it - video, photo, beauty, panorama, and SLR. To the right of the shutter button is the shortcut to the list of filters. To the left is the shortcut to the gallery of photos and videos.
On the upper part of the screen are the options for the flash and HDR as well as the shortcut to the camera settings along with the switch between the front and rear camera. The settings for both shooters are almost one and the same and include picture size, video quality, noise reduction, EIS, scene mode, exposure, white balance, anti-flicker, ISO, etc. As long as it concerns photo editing, you get the usual filters, effects, cropping, rotating, adjusting of contrast, brightness, hue, etc. options.

Primary camera

Ulefone Gemini has two rear cameras. Both shoot together under the SLR mode, while in the other modes, only the first camera is used. It packs a 13-megapixel Panasonic MN34152 SmartFSI sensor with a 1/3.06" size that outputs photos with a resolution of 4608 x 3456 pixels and shoots 1080p videos at 30 fps. The same sensor is used in the primary camera of the UMi Super and the UMi Max. The second camera has a 0.3-megapixel GalaxyCore GC030A sensor with a 1/10" size. Interpolated to 5 megapixels, it cannot work independently under any mode. Each sensor is coupled with a 5-element lens and their work is aided by a dual-tone LED flash. In this case, using the two cameras aims to create the so called bokeh effect, but in reality fails to do so, at least not in the way a real SLR camera would do it. This is mainly a software effect that does not succeed to merge the 13MP and the 8MP photo as for the end result to be with a naturally blurred background. In the normal photo and video mode, the camera makes good photos, suffice there is enough light, but it does lack clear definition and focus at times.

Secondary camera

For the front camera Ulefone Gemini uses a 5-megapixel GalaxyCore GC5005 sensor. This is an image sensor with a 1/5" size and a 1.12 μm pixel size supporting up to 640 x 480 videos at 30 fps. This sensor has been interpolated to 8 megapixels, too, and the photos are with a resolution of 3264 x 2448 pixels. The same sensor is used in three UMi smartphones we have reviewed: the UMi Super, UMi Max, and UMi Plus and in the Oukitel U20 Plus.


Ulefone Gemini has the current standard Android Music app that doesn't have many options besides several ways of sorting audio files and an equalizer. There's a basic set of sound enhancement features as a part of the Sound & notifications menu.
We perform the audio tests by using the TASCAM US-2x2 audio interface and the RightMark Audio Analyzer software. All audio enhancement features are disabled. The results do not take into regard the speaker. Ulefone Gemini has an Excellent result in frequency response, but scores Average in THD + Noise. The rest of the parameters are evaluated as being Very good, which leads to the same overall result. All this means that the sound is the way it is on most phones. The speaker does sound low, but if you use the speaker enhancement feature from the Sound Enhancement, the loudness increases. However, this happens at the expense of distinctiveness. So if this feature is on, you might want to use the speaker with lower volume levels in order to understand the voice coming out of it.
Test Value RMAA rating
Frequency response (from 40 Hz to 15 kHz), dB +0.05, -0.10 Excellent
Noise level, dB (A) -93.6 Very good
Dynamic range, dB (A) 93.5 Very good
THD, % 0.0070 Very good
THD + Noise, dB (A) -79.8 Average
IMD + Noise, % 0.010 Very good
Stereo crosstalk, dB -77.0 Very good
IMD at 10 kHz, % 0.017 Very good
General performance   Very good
Frequency response
Noise level
Dynamic range
THD + Noise (at -3 dB FS)
Intermodulation distortion
Stereo crosstalk


Ulefone Gemini does not utilize a dedicated battery app. You can monitor your battery's status and optimize its performance from the Battery settings under the Device menu. The layout is classic and includes toggles for Standby intelligent power saving and Display battery percentage, battery charging graph and information about the battery usage. As usual, the Battery Saver and Battery Optimization options are present along with a Schedule power on & off. Under the Power off menu there's a Super Saver mode. When you enter this mode, you can access only the Dialer, Contacts, Messenger, and Clock apps.
The device is powered by a 3250 mAh battery Li-Pol from Sony, which is said to provide up to 15 hours of talk time and up to 320 hours of standby time. The accumulator is non-removable and supports MediaTek's Pump Express Plus (PE+) fast charging technology. It allows a maximum output current of 12V through a standard USB adapter and transmission power up to 15 watts or above. The device arrives with a 5V/1.5A charger. For all battery tests that we run the screen of the device is calibrated to 200 cd/m2 and display enhancement features are turned off. The smartphone's system did not provide battery temperature data, that's why the red line in all graphs is flat. Our battery charging test shows that the accumulator needs a total of 2 hours and 32 minutes to charge from 0% to 100%. The process is not linear. It keeps a steady pace right from the start till the battery reaches 90% after 1 hour and 52 minutes. Then the charging speed drops significantly and the last 10% of the capacity are filled in 40 minutes. The browsing test simulates real user interaction with the browser. The graph demonstrates that discharging is linear and it takes a total of 4 hours and 32 minutes to deplete the battery completely. For the video discharging test we use a 1920 x 1080 video at 30 fps, captured by us with OnePlus 3T, looped in VLC Media Player. The video format is H.264 and its bitrate is ~20 Mbps. During the test, the battery discharged from 100% to 0% in 6 hours and 15 minutes. The 3D Graphics/gaming discharging test is based on Epic Citadel's tech demo in its Guided Tour mode. The battery of Ulefone Gemini during this test discharged from 100% to 0% in 3 hours and 24 minutes. Though the battery temperature was not reported by the device, it is worth mentioning that it got very hot during the test.

Final thoughts

Ulefone Gemini currently retails at USD 130. For this money you get a well-made device with metal body and very good display, clean and swift OS with all connectivity options present and working. Of course, no one would expect a top notch chipset for this price, but the 1.5GHz MT6737T would be enough, if you don't plan to play the latest graphics demanding games and videos. The battery life is not impressive, but is not bad either. What's more important is that the cameras of the device, which are its main selling point, make photos and videos of mediocre quality. Indeed, the specs totally correspond to the price, but the users will make the final verdict whether making a dual-camera smartphone just for the sake of having two cameras and not offering any added value is worth or not.