XiaoMi Yi dashcam focus problems

[slayer]

it's not HDR features though

I wrote already that HDR didn't work in chinese version. That's why Im asking now, if HDR will work in international version in future, when?

 

[tiz]

It may even turn out to be the glue causing the lens to refocus in heat and just removing that may help.

It also cross my mind this, I also thought after removing the glue the focus improved a little, but I wasn't sure.
Anyway, with the SJ optics I don't have the issue now.
Another thing I noticed is that the image is a little brighter now, in fact it is the same like in SJ. Before changing the lens it was a little darker during the day.
The night footage was almost the same in both SJ and Xiaomi. I will compare them again and I'll post here the results.

 

[Geralt]

It also cross my mind this, I also thought after removing the glue the focus improved a little, but I wasn't sure.
Anyway, with the SJ optics I don't have the issue now.

You confirm changing the lens fixes the focus blurring due to heat? Is it easy to replace the lens?

 

[tiz]

Today it was a sunny day, I was driving all day around until almost midnight.
I just compared the SJ4000 recordings with the Xiaomi's.
First of all, I can say I have no focus problem now. I didn't drive more than 30 minutes each trip but the dashcam was left in the car all day, in the sun, so it was heated by the sun, cooled by AC and again. No focus degradation.
Second, during the day, the image is brighter then before and I think sharper. I compared many minutes of video SJ vs Xiaomi, the image is too sharp, small details cannot be understood. Now I don't remember how it was with the original lens, I will put them back in few days to check. But maybe if I will de-focus a little the lens will be better, I will try.
And third, the night recording is better then SJ, more clear picture, the road signs are visible and understandable. This was also before, with the original lens, so I guess there is no change in night recording quality, except the focus, of course.

Changing the lens is very easy once you opened the camera, just remove the glue and unscrew the optical block of lenses. Better put a mark on it before unscrewing it, just to remember where to set it if you put it back, like a scratch on the lens ring at the vertical position. The difficult part is to find another block of lens from another camera and be compatible. The SJ lens screw has a slightly different step then Xiaomi's, but it only needs two turns to focus. The original needed about 6 or 7 turns to focus.
You need to use the app, better on a large tablet, to see the image when you focus the lens.

 

[Geralt]

That is certainly a bit of work to replace the lens and much improved focus with no degradation of video quality! I will begin this project in the summer!

 

[mikek753]

how much such lens set might cost?
I hope that whole SJ4000 doesn't need to be bought? Or ...

 

[jokiin]

how much such lens set might cost?
I hope that whole SJ4000 doesn't need to be bought? Or ...

Mobius lens might be a better choice, they use better quality lenses than SJ do

 

[Mtz]

Yes, jokiin is right, I see no reason to buy a SJCam lens or a poor quality lens to use on a camera with better specs than SJ4000.
Normally, Yi should send for free a replacement lens and about $25 to cover the disassembling job by a guy who knows how to do it and the travel and time lost to go to customs just for a lens. I am losing about 4 hours when I receive something from China and travel about 60KM to go to postal customs. Receiving at home by DHL will cost about $30 the DHL taxes to import a shipment.

enjoy,
Mtz

 

[mikek753]

Yes, jokiin is right, I see no reason to buy a SJCam lens or a poor quality lens to use on a camera with better specs than SJ4000.
Normally, Yi should send for free a replacement lens and about $25 to cover the disassembling job by a guy who knows how to do it and the travel and time lost to go to customs just for a lens. I am losing about 4 hours when I receive something from China and travel about 60KM to go to postal customs. Receiving at home by DHL will cost about $30 the DHL taxes to import a shipment.

enjoy,
Mtz

Would you explain how to get this "swap" from YI?
What did you do to get the replacement lens?

tnx

 

[tiz]

He didn't.
He said they should send ...

 

[AndrewL]

@Mtz thanks for doing this test. Was the windows rolled up and a/c off?

Mobius lens might be a better choice, they use better quality lenses than SJ do

How does one determine the quality of a lens?

 

[Mtz]

As you can see, the car was parked, engine off. But other reports are saying that the focus issue is because of internal heat and is starting after about half hour no matter day or night and until now here is spring.
Also the display have some problems because of heat, but this is not important for me because I am looking at display only when setting the camera and display problems is not affecting video quality, so is not a problem for me.

For me is impossible to understand how is possible to launch a camera on the market without at least one hour test. And if I remember correct also the Yi action cam had focus problems so they have some „experience” regarding this kind of problem.

I hope to not receive another advice to drive my car with AC on just to chill a camera.

enjoy,
Mtz

 

[qkarl]

I was going to buy this due to it's good night video quality but since I live in a hot area I think I'll just stick with something more well built.

 

[jokiin]

How does one determine the quality of a lens?

there's lots of things you'd look for when shopping for lenses, in this case though where you're just looking to use someone else's lens the Mobius has a better quality lens than the SJ, the YI lens has good image, just poor stability which is unfortunate, doesn't speak well for their QC to be using this lens on production cameras

 

[BAEK]

We received some reports about this before here in China but not recently. We optimized inside

Q1.
When did you optimize the batch product? I'm suffering same (heat -> blur) problems
Mine reads
YCS.1015.CN
2016DP0314
CA21LACNC01609

Q2. I'm living in korea and I bought CN version through internet in a month ago.
Can I get refund ?

 

[thancam]

Q1.
When did you optimize the batch product? I'm suffering same (heat -> blur) problems
Mine reads
YCS.1015.CN
2016DP0314
CA21LACNC01609

Q2. I'm living in korea and I bought CN version through internet in a month ago.
Can I get refund ?

Q2: You have to ask the peason who you buy from.

 

[reverend]

It's not even that warm in the UK (just hitting 20C but some of these are from 12C) but I'm really struggling with focus - I've been saving footage and just gone through 250GB worth and as you can see the majority is out of focus.

The last four screenshots are in focus and are just to prove that the focus drifts in and out quite severely and is behaving like the original DOD LS460W cameras I had back in 2014.

 

[reverend]

And just to really hit that home - here's taking one of the Yi dashcams many out of focus shots against the A119 camera from @viofo on the latest test firmware - you can see the difference using quality components makes:

From reading comments hopefully the Yi dashcam problem is fixed in hardware but that does mean that any early purchasers are likely to have the focus issues.

When the Yi dashcam is in focus it does a good job - it's just a shame it's more often than not out of focus as soon as it's not cold weather!

 

[maclow]

@reverend

It's more look like the focus si made on your dashboard ... or the reflection of the dashboard on the windscreen
Not due to warm

 

[jokiin]

@reverend

It's more look like the focus si made on your dashboard ... or the reflection of the dashboard on the windscreen
Not due to warm

if that were the case it wouldn't be in focus when the camera is cold