Received my Yi 2 4K in the UK from Geekbuying -Sample Footage :D

[hirsti99]

I have received my Yi 2 4K in the post from Geekbuying today, I am based in the UK.

Initial thoughts are that it is pretty much the same size as the original yi, video quality is pretty impressive, need to get it in my Quadcopter to see how it does but looks good on test shots.

On bad thing however is the inability to turn on lens rectification in 4K modes.
What is even worse, you can turn it on in 2.5K mode but 2.5K mode is permanently set to a 4:3 resolution and there looks like no wayto change it to a 16:9 other than post process it and crop to 16:9 using movie editing software. This is a backward step from the original Yi that allows crop in 2.5 K

Also the image stabilisation works great on 1080p however if you do have it enabled make sure you turn OFF lens rectification as it allows you to do it but the resulting video reminds me of how my vision is after a few too many alcoholic drinks

I will post so samples I took from the back yard.

 

[hirsti99]

Here are some quick samples from the back yard.

This is 4K hand held

This is the same footage that I put through Microsft Hyperlapse at x1 speed, you don't lose any resolution this way and you get the image stabilisation the Yi has in camera but for 4K

This is the same area/conditions taken on the Original Yi @ 2.5K

Here is the same area/conditions with the Yi 2 4K camera shot in 1080p 60 with Image Stabilisation in camera turned on

And here is the same area/conditions with Yi 2 4K camera shot in 1080p 60 with Image Stabilisation AND with Lens rectification turned on.

 

[kamkar]

That garden need a G-scale train

 

[hirsti99]

Xiaomi Yi 2 4K 30fps Timelapse

 

[hirsti99]

Here is a couple of slow motion videos.
There is a slow motion in camera option however this only can record at 720p.
If you want 1080 @ 120fps then you have to record as normal video 1080 @ 120 fps and then post process it with video editing software into a 30fps video to get the slow motion effect.

Here is 1080p @ 120 fps and post processed using powerdirector to 30fps

Here is 720p @ 240 fps and post processed using powerdirector to 30fps

 

[kwerkie]

Hi! I'm thinking of getting the Yi 4K camera from geekbuying.com. How long did it take for your shipment to arrive?

 

[hirsti99]

I pre ordered months before release however on day of release I got a notification it was shipped and received it 2 days later.

 

[andrewukr6]

please note 16:9 is being added to 2.5k very shortly, as well as alot of new features! If there are things missing from the camera software wise please bring it up on the very active official yi page as if it's a good idea they'll usually add it within a few weeks (no I dont work for Yi)

 

[hirsti99]

Thanks, they are actually adding 2.7K @ 60fps in 16:9 which is even better

 

[nodash]

If there are things missing from the camera software wise please bring it up on the very active official yi page…

(1) Where is that?

(2) I'm still trying to find out IF the lens is as badly infinity focussed as many on the original camera were (after two such purchases I don't trust that the experience of others who got well focussed examples) THEN can it be refocussed correctly without any MORE disassembly of the camera than the first version required (i.e. just remove front cover and hot glue and refocus)? Any hardware hackers know?

 

[hirsti99]

(1) Where is that?

(2) I'm still trying to find out IF the lens is as badly infinity focussed as many on the original camera were (after two such purchases I don't trust that the experience of others who got well focussed examples) THEN can it be refocussed correctly without any MORE disassembly of the camera than the first version required (i.e. just remove front cover and hot glue and refocus)? Any hardware hackers know?

I haven't heard of any cameras where the lens isn't focused correctly, just look at the footage on youtube, it is all very in focus.

 

[nodash]

I haven't heard of any cameras where the lens isn't focused correctly, just look at the footage on youtube, it is all very in focus.

Thanks, but your answer doesn't answer my question. First, look here: <https://www.youtube.com/results?search_query=yi+action+camera+focus> then look at my question again. It didn't ask what individual buyers in any quantity - 1 or 1000 - have found, it asked: IF refocussing is required in cam v2 for whatever reason THEN can it be done with no nore disassembly than refocussing cam v1 involved?

 

[hirsti99]

Thanks, but your answer doesn't answer my question. First, look here: <https://www.youtube.com/results?search_query=yi+action+camera+focus> then look at my question again. It didn't ask what individual buyers in any quantity - 1 or 1000 - have found, it asked: IF refocussing is required in cam v2 for whatever reason THEN can it be done with no nore disassembly than refocussing cam v1 involved?

First off why the hostility...please do not be hostile to people who are trying to help you.

You asked " IF refocussing is required in cam v2 for whatever reason THEN can it be done with no nore disassembly than refocussing cam v1 involved"
My answer was there is no evidence to show anywhere that version 2 (Yi 4K) cameras are being delivered out of focus, therefore they DONT require any after market refocus of the lens.

Secondly listed in this same forum is a thread that shows how someone has replaced the facory lens with an after market one, in this thread it shows a video showing step by step intructions on how to disassemble the yi 4k camera to get to the lens, this would be the same process for adjusting the focus or replacing the lens.

The thread is https://dashcamtalk.com/forum/threads/3-8mm-12mp-1-2-3-lens-for-yi-4k-ii-action-camera.20420/

 

[nodash]

No hostility in the writing, apologies if phrased such that it appeared so in the reading. Clarifying a question that got an answer to a somewhat different question might look like hostility to some, I guess, but it isn't.

Two points: firstly, Yi Technology is very unlikely to have focussed the lens on infinity but on a much closer point that will render infinity "acceptably" in focus by some depth-of-field criteria that, like what is "acceptable", resemble the "proper" length for a piece of string. It depends on what you want to use it for. As well as theoretical calculations based on pre-modern spherical lenses there is a whole confounding factor of diffraction to consider, especially in the case of these tiny components. The excellent documentation accompanying an Android app and Windows program, "DoF" by Jonathan Sachs, provides a basic introduction to the advanced subject, if you are interested.

In the thread you quote (thank you) the tear down of the camera, which I saw before I posted the question or its "hostile" clarification, does not answer it either: the entire lens and sensor assembly is simply shuffled out of shot and forgotten after a significant amount more disassembly than was required to refocus the v1 Yi lens had already taken place (not a fault of video-making, as the tear down, not any consideration of lens refocussing, was its intent).

However, I now see, from a later post by mavortium, that only a little more disassembly than v1 required is needed on the v2 (just prying off the ring around the lens, which is incorporated into, and comes off with, the front cover on v1) and that answers my question, albeit unintentionally and indirectly.

Finally, I am indeed somewhat hostile on this topic, but only towards Yi Technology. I actually bought two Yi v1s, the first while I was transiting Hong Kong, and it was grossly out of focus at any distance much over 4 or 5 meters. However, I was able to fix it by the widely publicized method shown on YouTube. As I am testing for a rig which will incorporate several, I bought another, but this time, having discovered that any service that might be available did not travel outside China, a USA version from Amazon. It also had an infinity focus problem, but a much more subtle one that most people would not notice, although infinity was at least as sharp as those in the various v2 demos around the net. Using the same method brought it to an "acceptable" degree of infinity sharpness for MY purposes. However, in that case, when it was refocussed the left 1/4 (and only the left 1/4) of the image was significantly out of focus at infinity. A clever choice of hyperfocal distance had masked a lens mount problem. which they had even tried to correct with a very thin HDPE shim, both together succeeding well enough to make it all but invisible. When I asked Amazon about a warranty repair, because I was not in the US (where I'm based) but far away on a long term contract they could only offer a refund. Paying the relatively large international freight cost to get a friend to return it from my US address and send it back or having to settle for a refund at half that cost was not a choice I was happy with, so they suggested I contacted Yi directly. I did, and got only inscrutable oriental silence in return. I'm willing to chance a third try, but only if I'm sure I can refocus a nearly but not quite, for MY purposes, acceptably infinity-focussed lens without a less disassembly than the tear down video went through to get to it.