Hubsan have been releasing a whole string of little X4 multirotors the last year.
First they released a straight microrotor, next they added a camera to that, make that a couple of revisions of the camera equipped X4. in October they released the latest revision of the X4 FPV, the h107D (the 4th micro X?)
Click through for 360 spin of the X4FPX - Video UN-BOX and review
My Video UN-BOX and Initial review... please read the rest of this article to see the things I have learned about the X4 FPV since the initial unbox.
The new hubsan X4 FPV is a elegant single piece little quadrocopter.
The obvious comparison for this product is the Walkera Ladybug FPV package. Wakera did that by making a standard, rather large traditional control TX, with a build in screen. and a attachable FPV camera module the TX5805 which is very small and compact, and also easy to modify for better performance. But I gotta say the new X4FPV is far sexier looking than the ladybird.
Hubsan on the other hand have included the camera, video transmitter into the shell of the Hubsan X4, the result is one develish beautiful little quadcopter. a package that truly look well designed and made as one unit.
The obvious disadvantage of the single unit approch is, that for those of us who like modifying stock items.. well its just not that easy with the Hubsan X4 FPV.
Hubsan have chosen a interesting path in their video system, and deliver something along the lines of pretend HD, the nominal resolution of the video is claimed to be 720x480 pixels, the build-in DVR however record 720x240 pixels video. So before we draw conclusions lets chcek out facts.
The X4 FPV use standard 5.8gig video downlink. traditionally 5.8 delivere SD video which is roughly 0.3 megapixel, since the X4 is using traditional 5.8, there is no reason to believe Hubsan have found a way to double the bandwith on the radio, and more to the point, high-quality FPV systems using video transmitters more expensive than the Hubsan X4, so lets rule out Hubsan having a better video transmitter than guys like immersionRC, and the high-end transmitters ONLY deliver actual 640x480 video under ideal conditions, often dropping resolution when the signal is less than idea.
But I digress, it is reasonable to assume that the actual video signal is 720x240px which is only 0.17megapix, Im guessing that Hubsan have realized that doubling the height of the pixels on the screen makes for a very attractive video image that seems quite high quality and very sharp compared to a diluted SD video image. as a result the video from the Hubsan X4 FPV apears quite good compared to most similar systems, and I would say better than the video in the Walkera Micro quad system. VERY good move Hubsan.
BUT before we crown the hubsan king of the micro-FPV, there is a serious kink in the system, the camera in the hubsan X4, the camera have a narrow angle of view, WAY less than 90 degrees, probably closer to 45 degrees, why do that matter.? because flying low level quad copters, rely on wide-angle lenses for good control of the aircraft, I mostly fly with lenses giving me about 120deg field of view.
Hubsan have chosen a a very small sensor, and a small diameter for the lens, this means that it is unlikely to be able to find a wideangle lens for the camera. Unlike the walkera TX5805 vtx which can easily be upgraded with a D lens from a keycam 808.
I did add this smart-phone fisheye lens from Amazon which made it much easier to fly
THE CONTROLLER and Video screen.
The new FPV reciever is a quite elegant design, unlike Walkera, Hubsan have chosen to put the screen on the upper part of the reciever, I like it that way, it is easy to see the screen, and the screen is huge.
The ergonomics of the new transmitter is quite good, and quite comfortable to hold for a extented period of time.
There is one glaring problem with the combination controller and video reciever, the big screen is power-hungry, and the system only use 4AA batteries, I sugget if possible making room for 8 batteries in future versions of this reciever.
All in all, Hubsan really have done a good job on this system and I suspect competitors will be looking closely to the Hubsan design for their future designs.
The reciever have a mini-jack plug on the left side which permit you to plug in a pair of video goggles for FPV flying.
I was positively surprised to see my FatShark Attitude goggles display the Hubsan X4 FPV video correctly, that right there is a huge sales points.
I must say, as someone who spends quite a lot of time flying FPV, once you put goggles on, flying a micro is incredible good FPV flying practice, the micro quad is like a great flight-simulator, and if you have FPV ambitions, I highly recommend flying with goggles on a micro quad. either by plugging into the controller, or using a walkera ladybird you can fly with wireless FatShark goggles.
In practical use, the video system works well, there is a sort of "patch" antenna build into the controller, this means that the video reception is directional and best when pointing the top end of the reciever towards the X4, it is no problem to fly directly behind yourself, but at any distance behind your self you will quickly loose the signal, solution is simple, keep turning and face the radio towards the X4.
How do the X4 fly.?
The simple answer is "QUITE WELL". it is easy to fly, the body of the aircraft produce enough "drag" that the thing move a bit slowly and do not accelerate too quickly and it is easy to maintain control of the aircraft, the flight behavior is easy and predictable making the aircraft wonderful to learn and gain basic flying experience.
I really only have one niggle with the X4's flying. Strangely the throttle is quite touchy, and you will find it can be a bit challenging to maintain a consistent altitude during flight, particularly when flying FPV.
Flies quite well,
Integreated Monitor and TX control
Controller with build in DVR.
High quality video system.
FatShark compattible (on the higher channel range at least)
Hard to modify,
Narrow Video Field of vision, pathetic actually.
Control TX battery drains very quickly.
Recording saves as AVI motion JPG files.
Read more about the Hubsan at RCgroups.com