Though I do have a decent Fuji diving/tough camera (up to 20m, tested) I decided to get another, sports camera, that could , with a diving case, go safely and inexpensively to 40 or 60m, and to also use on cars, bicycles, at home etc. as a sports cam.
I bought the Xiaomi Yi (the original version), and then I also bought the H9 (Eken?).
The H9 is blue (it was the cheapest at the time)
The Xiaomi costs about $70 and the H9 about $35, half the price. I got the Z23L version of the Xiaomi, which has some improvements regarding focusing.
They both had decent reputation, and they both can use various of the accessories designed for other sports cameras.
You can buy spare batteries for any one for a few dollars.For the lazy readers: For a quick, cheap, decent fix, get the H9. For the best picture quality, get the Xiaomi.
Just looking at the size of their individual lenses gives you a pretty good idea of the sensor size, in each camera.
The app and the available setting for the Xiaomi are superior to the ones for the H9, and you usually forget that you do not have a viewfinder.
The H9 is a bit bigger, but it does have a screen. You can buy a screen for the Xiaomi, if you want to.
with AAA batteries next to them
Despite claims, they are both basically 1080HD cameras, with the possibility to take 2.7K or even 4K videos, at reduced fps. They both focus at a distance, no macro. You need to be careful as objects closer than around 10cm to the camera will be out of focus. This is an issue, as, with these wide angle lenses you need to bring objects quite close to the lens, to fill the picture with them.
They can both take very fast video, at lower resolution, and loop video, so that they can be used as dash-cams.
They can both take burst photos and time interval photos.
The Xiaomi (155) has a wider angle lens than the H9 (170) and in my pictures, the Xiaomi produced a significantly wider view. The Xiaomi also has a setting for correcting the fisheye effect you get from the wide angle lens. It works well.Same distance and objects, and taken at the same time
H9 (at its 12MP setting)
With respect to picture quality, even though the H9 is not bad, producing nicely saturated pictures, the Xiaomi is significantly better, especially with respect to recording detail in brighter areas of the picture (not burning the picture). You can also select between spot, matrix and centre metering and it works very well. The videos are good from both cameras, but again, the xiaomi ones are a bit better.
Now look at the difference in picture quality, between these two crops.
Pictures with the Xiaomi, in a difficult lighting environment, showing how the sensor copes with dark and bright areas, in the same picture
Still, you can use the H9 as a proper camera, even viewing your results afterwards on the screen, whereas, with the Xiaomi it is not easy to know exactly what you are taking a picture off, unless you have a phone or tablet, with the app running, with you. I used it yesterday for taking pictures at a birthday party…
Having the WiFi on depletes the battery very quickly, in the Xiaomi, whereas using the screen of the H9 does not have such a powerful effect. You should be able to get about an hour of video/picture taking from both cameras, if you limit the use of WiFi and the screen (the screen on the H9 switches off after a set amount of time).
Summarising, the Xiaomi does have the noticeably better picture quality, due to its Sony 16MP sensor, and has a better feel to it, better build quality, better feel to the buttons. It does not come with any accessories, so you need to add an extra $20, or more, for extras like straps, a diving case etc. It does not have a screen, but it does have a decent app, for changing the various settings, and which allows you to use your phone/tablet as a viewfinder. There are plenty of camera specific accessories available.
The H9 comes with various accessories (bought individually they could cost as much as the camera package), including a diving case, 40m (mine was scratched), and it does have a decent screen, which can be used to make the various adjustments. It has an app to, but it is of limited use, and not really needed. There are not many camera specific accessories available, but it can use the accessories of the sj4000 (they have the same body and many specs), and many generic accessories. However, though it claims 12MP, the sensor it has is a 4MP one, which can produce the 12MP through interpolation. It also has 4K video, but at only 15fps.When buying
look for the lowest price – you may be able to get it much cheaper if you opt for a colour that is on offer, on that day. The Eken h9 and the plain H9 appear to be the same camera. The Sj4000 is also very similar, but twice the price. The L version of the Xiaomi is the one to get. There is a new version out now, with better specifications, but it is over $200.
If you are interested in picture quality go for the Xiaomi. For videos they should both be fine. If you need a standalone camera get the H9.
They both have HDMI outputs and can be used on the, right, quadcopters for FPV.
Note that they both have wide angle lenses, so they are really designed for objects nearby, or larger, panoramic views.
The free diving case you get with the H9 does not feel very well build. You may still need to buy an aftermarket one.