Just got the A119S and the video is blurry :/

[gse]

how you retain the parts fixed in place for the focus check / video.

I use a tape tape, one turn on the thread, the lens does not break when adjusted, then fix a drop of nail polish.

 

[IvanhoeYU]

there is an error in the video;

the new V2 lens is f1.6 (vs. f1.8 for V1), so the EV formula brings different values

 

[IvanhoeYU]

I use a tape tape, one turn on the thread, the lens does not break when adjusted, then fix a drop of nail polish.

View attachment 34186 View attachment 34188 View attachment 34189

thanks, good idea if needed ;-)

 

[IvanhoeYU]

question for experts your are, please? a little bit tricky, see long, so read it when you have the time

what is the main "heater" inside the a119s?
I've thought it's the processor, but @Dont Knowler talks about the "hot" sensor imx291 in the a119s vs. "cold" ov4689 in the a119?!

Where I would like to come...

Does the operating temperature is higher in the main chamber of the a119s, with the processor as the source of the heat, or in the small chamber with the lens/mount/sensor imx291???

I've thought that this lens chamber is "suffering" from the heat of the main processor chamber, and the main reason why this small lens housing is closed and isolated from the main one.
Like this having the independent ventilation holes in front, so exposed to the exterior and isolated from interior.
So the air inside of this lens chamber supposes to passively isolate it from the heat of the processor, of course if this hypothesis is true.

But if @dont knower is right and the sensor is the source of heat, I'll go with the extra hypothesis that the main chamber with the processor is "colder" as better air cooling with a lot of ventilation around and in absolute bigger air volume, there is an interest to "connect" them, small and big chamber, with some extra drilled ventilation holes on the lens plastic housing, improving the air circulation and get lower temperature globally, so with the simple passive air circulation inside.

I've seen also on some videos some kind of metallic cooler tape over the processor, so maybe this kind of tape around the lens can help as the mini cooling radiator, waiting for the better solution, but if @jokiin is right, the metallic part conducts and keep higher temperatures to the electronic board/sensor/lens, so maybe it will be even worst.
Up to @gse, @jokiin use the metallic mount with the same imx291 sensor/board to avoid the problem that @viofo face actually with the V2.

@Nigel's idea is that the lens could be suffering from the temperature, moreover the dilatation of the mount, better cooling will help more and we can keep the focus of the "cold" stage setup.

I'll probably don't touch the focus for the moment, waiting for the @VIOFO_Support to bring some technical answers and fixes.
We should trust engineers that have been developing this product for months.

Assuming that there is the prove and that in the "cold" state there is no focus issue ;-), the cooling improving of two chambers first and of course resolving the focus drift sensibility up to the working temperature with the improved mechanical mount & right choice of composite materials or metals will probably come to.

cheers

 

[SawMaster]

I would not drill the lens housing. You do not want any dust getting inside there.

Phil

 

[IvanhoeYU]

agree a little bit on that but anyway there are ventilation holes in front of it so the dust comes into it sooner or later and from exterior.

Of course if some extra air circulation is added, the basics of the idea, it will improve the air circulation, cold air comes in from the bottom, hot air goes up, basic rule of thermodynamic, and you're right more air brings more dust too.

Your're afraid about the lens, isn't it?

Dust should not be the problem supposing that the assembling of the kit lens/mount/sensor is "dust proof" and it's probably assembled in the dust free production condition. Lens for sure, mounting/sensor should be if they are not crazy...as if not couple of months later I can imagine the result of the footage.

if not, why they haven't completely enclosed the small chamber with the lens/mount/sensor.

For me the refocusing of the lens and realigning of the mount up to the sensor is much more dust-wise risky for the DIY environment we have, vs. having couple of ventilation holes.

But of course, we'll not drill them just for the fun and immediately, I would like to thank you for your concern, this is why I like this forum and people here ;-)
It's more some kind of 360° brainstorming of some theoretical ideas. I use 360, because without the support of @VIOFO_Support we end at the start-up point.

Assuming that nothing is stupid when we don't have all relevant information, know-how, development backup, fixed issues or build.

Some help comes from @jokiin and @OCD Tronic , it's true and we appreciate it a lot, thank you again, but hearing @viofo will be helpful too.
The "small" issue is that @VIOFO_Support doesn't share a lot ;-) and sounds strange to us.

Personally I've thought that they don't exist, really, as it is the case with many no-brand manufactures, but up to some of you they are trying to build the brand and all brands have good technical support...up to some they are good.
Maybe they are still on Holiday, even if I'm not wrong the holidays in China are finished and people are back to work last week...but you know, as usual it takes some days to be "acclimatized" and back to real life
Best Regards to @viofo too.

 

[kosinsky]

I have the same issue with the video becoming blurry after a while. I am going to return the camera as I don't expect it to fix itself and I've already had my share of problems with the JooVuu X.

 

[gse]

For me the refocusing of the lens and realigning of the mount up to the sensor is much more dust-wise risky for the DIY environment we have, vs. having couple of ventilation holes.

In this case, the ventilation holes will not help.

 

[Dont Knowler]

But if @dont knower is right and the sensor is the source of heat

There are indeed several sources of heat which are relevant for a dashcam, including the sun, the processor, and the sensor. However my guess and my point are, that it is most likely the hot sensor which makes the difference, causing the A119S to have focus drift with a plastic lens holder, while a very similar A119, to which all the other sources of heat also apply, but which has a "cold" sensor, is not known to me to have this focus issue.

 

[Nigel]

There are indeed several sources of heat which are relevant for a dashcam, including the sun, the processor, and the sensor. However my guess and my point are, that it is most likely the hot sensor which makes the difference, causing the A119S to have focus drift with a plastic lens holder, while a very similar A119, to which all the other sources of heat also apply, but which has a "cold" sensor, is not known to me to have this focus issue.

What is the difference in power consumption between the hot and the cold sensor? The A119S sensor has the lower resolution and it is a more recent design, it shouldn't be using a lot more power...

For me the refocusing of the lens and realigning of the mount up to the sensor is much more dust-wise risky for the DIY environment we have, vs. having couple of ventilation holes.

You don't need to realign the mount, just rotate the lens about 1mm so that it is in perfect focus when warm instead of when cold. No real risk of dust doing that.

In this case, the ventilation holes will not help.

Agreed, ventilation holes will make almost no difference.

 

[jokiin]

processor and CMOS sensor are the two major sources of heat in any dashcam, the heat difference between OV4689 and IMX291 will be negligible

 

[gse]

jokiin
факты - это упрямая вещь, никто не отменял законы физики.
A slight difference, it just affects the defocus.

 

[IvanhoeYU]

@jokiin, please, why do you choose the sony imx291 over the ov4689?
looking only specs on paper, the ov4689 seems to be more interesting to pumping up, except the low light sensitivity that seems to be more interesting for the night parking mode, not so much driving condition day/night...or I'm completely wrong

 

[jokiin]

@jokiin, please, why do you choose the sony imx291 over the ov4689?
looking only specs on paper, the ov4689 seems to be more interesting to pumping up, except the low light sensitivity that seems to be more interesting for the night parking mode, not so much driving condition day/night...or I'm completely wrong

we are concentrated on developing dual channel models, some of the things that you can do with OV4689 only apply to single channel mode so don't suit what we need, the Sony sensors are a better fit for our needs

 

[IvanhoeYU]

you're right, if the hardware is available at reasonable pricing level, the dual channel is exactly what the market will be probably looking for.

 

[jokiin]

the dual channel is exactly what the market will be probably looking for.

it depends on the sales channel, dual channel models are more popular in retail outlets than online, for a lot of people the dual channel products are not so easy for DIY installation, particularly for later model vehicles with side curtain airbags etc

 

[BCHobbyist]

there is an error in the video;

the new V2 lens is f1.6 (vs. f1.8 for V1), so the EV formula brings different values

no error, VIOFO shipped me the new v2 F1.8 green coated lens for testing, all original v1 lens were F1.6 as shown on the old VIOFO website describing the 7G Lens with 6 glass elements.
http://www.viofo.com/home/34-a119s-1080p-60fps-car-dash-cam.html

 

[cyberspace]

Proof of defocusing due to heat courtesy of @gse . (2.5MB gif)
40 minutes between frames.