Xiaomi MiJia Mini 4K Action Camera Review

Whenever a new camera is due, it is always a special day. I bet you know the feeling. So when the DHL pickup stopped in front of the house, I was as excited as my doggies, because we all immediately knew that Something from Very Far Away has arrived.

Then I signed for the yellow-red-gray envelope and scissored my way through it to get at the sturdy cardboard box. Inside was yet another, smallish but beautifully made white presentation box, wrapped in a protective bubble sheet. It was solidly sealed in a tight plastic layer. I cut it carefully away to open the box and let the daylight shine upon…

What’s inside the box?

… the new Xiaomi MiJia Mini camera, a.k.a. Mi Action Camera 4K, model YDXJ01FM, sitting amid this perfect piece of packaging!

I lifted the camera with its cardboard spacer out from the box, and underneath was yet another paper spacer containing one battery, and one thin and short USB cable. That’s all?

Nope. There was also a small rectangle of the zigzag-folded piece of paper that I instantly recognized as my always-first Readme – a Quick User Guide.

Printed in Chinese ideograms. And in… nothing else.

Twenty seconds of fast-forward around the frustration…

Closer look

I could clearly feel my blood pressure rise, attempting to overcome the weight pressing down on my patience valve. How on Earth am I going to read this Guide? And then I thought, maybe I should trust my instincts. Just discover how to switch the cam on, and with Lotsa Luck maybe hen-peck my way deeper? Maybe I can find some tongue that I comprehend before I click, touch, or swipe something wrong and turn the camera into a paperweight.

Truth be told, first I had to really admire the cam because even while it’s still just a piece of dead hardware, it definitely is one beautiful product. I know you can see the MiJia Mini on about zillion other pages, but let me try and convey just my personal impressions.

Design & Quality

Xiaomi MiJia Mini is really small, bordering on dimensions where the size of my fingers gets in the way of operating it. The black camera sides have fine sandpaper texture that offers good grip on all four lateral sides. Front camera plate is also anthracite, in the powder-like matte finish, while the whole back surface is made of glass. Width vs. height ratio of the camera’s round-cornered shape is roughly 16:9, which is quite an elegant form in itself.

The cam’s optical system is recessed in a sturdy metal shark skin-textured ring which is very grippy, although it is not meant to be manipulated at all. However, if MiJia ever decides to create some kind of quick-attach accessory (like an attachment hoop for dash cam use), this surface would offer excellent friction. Consider it one donated idea.

While at that, it is obvious that some sort of lens cap would be useful to shield the optics from fingerprints, or mechanical damage. Such a lens cap is missing for now, but if MiJia produces the thing, it should be made so that it hinges at the ring encircling the lens tube. It would be very practical to quickly flip the lens cap open or closed. Consider it another donated idea!

There is a LED indicator on the front plate. It shows red when the camera battery is charging, blue when the cam is operating, white during data transfer, and orange when you’re halfway through the battery capacity. One more red LED is topside, by the main and only button.

This single large metal button is recessed into the top surface, functions as Power On / Off, and also Shutter / Record command – both photo or video, camera mode dependent. Later I found it was more capable that that!

Also topside, there is one of the microphones (the other is below the USB port) listening through a single hole. A row of six holes above the lens is where the speaker speaks from.

The USB port on the left side has a sliding cover, which is one welcome feature against the lint-in-connector problem. On the camera underside, another cover hides the battery and microSD space. This cover slides out and springs open, but only if you press at the arrow-marked spot which is actually a small, elegant lock. Otherwise, it won’t budge.

An ¼” standard tripod bushing in chromed metal situated in the optical line under the lens and the cam data imprinted on the battery cover conclude the camera underside inspection.

The touchscreen monitor is a 2.4″ LCD with a resolution of 960×480px; the largest among all the similar action cameras to date. It functions as a good touchscreen that you touch and swipe to pick among various settings.

This is sufficient for setting things up and controlling the frame, but don’t look for extra quality in color, or very good visibility in the strong light, though the monitor light intensity is adjustable among Normal, Medium and High.

Specifications

•  
•    Chipset (Processor)
•    Image sensor
•    Lens
• F-Number (maximum aperture)
•    Weight
•    Size
•    Screen
•    Max image resolution
•    Video resolution
•    Video compression format
•    Image format
•    Memory Card
•    Battery
•    WiFi
•    Connection
•    Remote controller support
•    External Mic
•    Video Stabilization
• HDMI Out
• Recommended Retail Price

• Xiaomi MiJia Mini 4K
• Ambarella A12S75
• 
  Sony IMX317
  
  8 Mexapixels 1/2.5" CMOS
  
• 
  7-element glass lens
  
  built-in UV filter
  
  FOV = 145⁰
  
• F2.8
• 99g with card and battery
• (W x H x L) 7.15 x 4.27 x 2cm (2.95cm at lens side)
• 2.4″ (960×480px) LCD in 16:9 format
• 3840×2160 (8.3MP)
• 
  4K: 3840 x 2160 - 30 fps
  
  2.5K – 2560 x 1440 – 30fps
  
  1440p: 1920 x 1440 - 100/60/30fps
  
  720p: 1280 x 720 - 200 fps
  
• H.264
• Image format : JPEG, DNG
• up to 64GB
• 1450 mAh
• USB
• $99

Check the price

App

There is a QR field in the Guide which lets you open usual sites to download the Mi Home App, from Google Play (Android) or App Store (iOS). The App lets you connect your phone to the camera’s WiFi and offers a remote user interface that enables you to change several settings, to start / stop recordings, and to view photos or videos.

Frankly, I delight in using my cameras out of hand rather than overloading my phone with yet another program to deplete the meagre power that the phone battery has, so I am skeptical about any app right from the start, but I downloaded it anyway for testing purposes.

I tried it and it wouldn’t work with my phone (Android v.6), so I scrapped it. But experiences usually vary. Perchance you’d need this App, in which case you should visit the above links.

Quick start guide

What I got with the camera was a strip of folded paper printed in Chinese ideograms. There are several neat camera drawings where all relevant parts are number-marked. Still, it was of no use to me. Why is it a problem to add small, multi-language Manual with the product?

Firmware

To put it succinctly, any Manufacturer’s website should have Guides, Manuals, and Firmware on display and available right under the product photo, but that is not understood – which is one real mystery. So I traveled the net far and wide, to finally stumble upon a site where I found new cam Firmware, and enough sensible data to bypass the pretty leaflet. Kudos to the author who saved me with these instructions! The least I can do is make it known here too.

NOTE: You always update any camera firmware at your own risk!

– Download the firmware file firmware.bin (v0.6.9.2578)
– Put the firmware.bin file into the root directory of an empty, FAT32-formatted, high-speed memory card.
– Verify the camera battery is full. Turn camera Off. Put the memory card into the camera.
– Turn the camera On. The camera will boot to a prompt screen in Chinese. Touch the button on the right side of the screen to confirm the firmware update.
– The camera will power off and flash its lights for 1 – 2 minutes. When the firmware update is complete, the camera will reset.
– Once the camera has reset, swipe downwards from the top of the screen.
– Tap on the Settings (leftmost) icon and scroll all the way to the bottom of the Settings menu.
– The Language Selection is the third option from the bottom of the list.
– Select English. Confirm. Your camera interface is now in English.

So after having the Firmware* updated, I found the Settings option for the Language Change. The camera interface became alive, and bristling with options that I could actually use!

MiJia: please add a leaflet in several popular lingos which first points the buyers of your cameras to where and how the interface language can be changed! This proved to be of top importance, because it opens all the other locks and limits. Since there is a Help file already in camera (!), all cam operations quickly become familiar – and efficient.

(* See also another link in the Erik’s comment below!)

First Attempt

The interface via the cam’s touchscreen employs swipes and touches to move through the numerous options available.

Swipe downward from the monitor top to reveal four basic menu symbols that stand for General Settings, WiFi, Monitor Lock, and Power Off.

Swipe to the left to check your recordings, and to the right for photo and video options. Tap at the SliderSwitch symbol in the lower right corner of any mode, and a submenu for that mode will let you tweak all the mode-specific things in there.

Long story short, once the interface language became readable to me, the rest was really easy, because this piece of software is very well conceived, and intuitively quick to use.

Video Quality

Video options let you control Resolution (4K @ 25fps, 2.5K @25fps, 1080 @100/50/25fps, 720 @ 200fps), Quality (Superfine, Fine, or Normal), Lens Distortion Correction (On or Off), Mic Mute (On or Off), Metering Mode (Spot, Center, or Average), EV (0, plus or minus 0.3, 0.7, 1, 1.3, 1.7, 2), WB (Auto, Incandescent, Sunshine, Cloud, or Underwater).

Then there is a Timelapse Video, where you can pick Intervals (0.5, 1, 2, 5, 10, 30 and 60 sec), Video Length (6, 8, 10, 20, 30, 60sec, and 2 min), Resolution ([email protected], 2.5K @ 25fps, and 1080 @ 25fps), Quality (as above), Lens Distortion options (as above), Stamp (Off, Date, Time, Date & Time), Metering Mode, EV, and WB as explained above.

You might enjoy Slow Motion Video by mastering control of Speed (2x – 1080px, 4x – 1080px, 8x – 720px), Quality, Lens Distortion, Metering Mode, EV, and WB as already described.

There is the option to Loop your records, where new records overwrite old ones. You can set the Video Length (1 thru 30 min), Resolution, and other already described variables.

Shooting Video+Photo is possible too. Things controllable there are Interval (from 5 thru 60sec), muting of the microphones, plus the choice of above-described options.

As to the quality, see for yourself. I think daylight footage is very decent, considering, but night shots are not what this cam has been made for. Still, since daylight actions prevail…

Photo Quality

Photo Menu lets you select Aspect Ratio (16:9 or 4:3), Output Format (JPG or JPG + DNG*… yes, this puppy also records RAW!), then all the other things, plus Shutter (Auto, and from 1/60 thru 8 sec), ISO (Auto, or 100, 200, 400 and 800), also Color (pick among Standard, Bright, Artistic, Film, and Classic).

Self-timer called Timer lets you choose between 3, 5, 10 and 15sec. Burst Rate can vary from 3, 5, or 10 pics per sec, 10 pics in 2 secs, 10 pics in 3 secs, and 30 pics in 6 secs.

And there is also the Timelapse Photo mode, where, similarly, you pick the interval, aspect ratio, lens distortion correction, stamp, metering mode and the usual rest of said options.

Photo quality is very good, except for a slightly annoying delay between pressing the shutter and a photo being taken. It’s conceptual, but there you are. Never forget the camera price.

* DNG stands for Digital NeGative file and is also considered to be a RAW image file. It is Adobe’s proprietary image standard that was created to store image data in a generic, highly-compatible format, unlike RAW files that have specific formats based on manufacturer and camera type.

UPDATE 09/11/2017 – Adding four more photos made with MiJia Mini:

FOV and DOF

The Field Of View seriously affects Depth Of Field (a.k.a. Depth Of Focus). Sometimes it is a problem, like when one wants to have blurred backgrounds. At other times it might be a sort of blessing, like when you want some simple, rugged optical system that can withstand rough usage. Exactly these features are paramount in action camera optics where there are no moving parts to break down or go out of alignment.

As a rule, the wider the FOV (the lens input angle) the longer the Depth Of Field (the lens ability to render near and far objects sufficiently sharp). Typically, the long DOF occurs with Fisheye lenses, and the shallow DOF is characteristic for telephoto lenses. Another factor influencing DOF is the Aperture (f-number), but you may disregard it since action cams have a single, constant aperture value.

While faraway objects recorded with a wide-angle lens will be sufficiently sharp, sometimes you’d want to know just how close you can approach your objects, and still have them rendered sharp. Or, what’s the minimal distance for any particular optical system before the images become blurry? Simply do this test.

Set several objects up at measured distances from “ground zero”, which is the point of view (POV) where you hold the cam while photographing. Make a few photos of the scene, and determine where the unacceptably blurry zone ends. That would be the closest distance between your camera and any object you’ll want to appear sharp in the picture.

Bear in mind that every action camera with different FOV and/or f-number will have a different DOF, and its sharp zone will begin at a different distance from the camera. Things will also change somewhat if your near objects happen to be in the middle of the framed scene. In short, these things need to be experimented with before committing oneself to some serious projects!

Sound Quality

Quite good, as far as I can tell across the range of tonal and noise frequencies. I also wanted to record the wind over bare cam’s mics, as certain action soundtracks might suffer from such noise. Best listen for yourself to the sound recorded in the short footages below:

Battery Test

Several test recordings were made outdoors. I did the recordings at a setting of highest resolution and also at the highest frame-per-second rate. In all tests, the monitor and WiFi emitter was constantly set to ON, so as to force the highest level of energy spending. The battery was charged in-camera, using a Tesla smartphone charger.

This camera battery at 1450mAh is quite capable, as action cams go. It is good for ~90 minutes of 4K recording, or for about 120 minutes of 1080p recording at 60fps.

Charging the battery with any typical smartphone charger featuring 5VDC / 1A output took about 100 – 105 minutes. I also used my smartphone cable that has the same USB connector. It made no difference; neither with the charging nor with data transfer.

NOTE: the charging / depleting values are never absolute since there are variables that influence the tests, such as ambient temperature, internal temperature, usage with or without protective housing, specific charger, production batch, also whether the monitor, WiFi or Bluetooth are Off or On, etcetera.

Waterproof Case

There was none at the moment of this writing  but…

1. UPDATE (thanks to Erik’s comment below). There seems to be an adequate case made for  this camera, though. On eBay it is described thus: (c/p)

Summary

Xiaomi Mijia has a 1/2.5″ 8MP Sony Exmor IMX317 sensor that looks through 7-element camera lens which has a FOV of 145° and an UV filter built right in. A Bosch gyroscope and 3-axis-accelerometer take care of 6-axis electronic image stabilization that is active when the camera is turned on (actually you can’t switch it off).

The images can be corrected rectilinear which is one among many user options, so the straight lines of objects appear straight in the image.

Photo and video files are processed by Ambarella A12 processor that is also used in some other action cameras, like several models produced by SJCAM, ThiEYE, or Hawkeye.

To conclude: the Mi Action Camera 4K is an almost excellent device that could be made better, merely by taking into account the things listed as Not Good. To my taste, it should have been built into an at least weatherproof case. This is supposed be an action camera, isn’t it so? Well, most of the action worth recording occurs in the Great Outdoors and an action cam should be able to shrug off the most adverse conditions out there!

MiJia… Please, just build the same quality right into an underwater casing. No middle box.

Or more simply: do away with leaky boxes forever, and you will be on top of the tree!

Good things:

• Very good price
• Neat manufacturing
• Relatively large battery
• Quality optics and sensor
• Useful and speedy interface
• Many options and sub-options
• Very good design, excellent finish
• ¼” standard metal tripod bush in optical axis

Not Good things: