Adjusting focus ( heat related shift )

[kamkar]

So today i took the 0906 apart and redid fucus with the camera connected to my TV with a HDMI cable.
The process was sort of uneventful, but i will tell why sort of later.

First taking apart the 0906, it is actually not that bad, even when i did the same for my much similar 0806 a long time ago.
But you be wise to pay attention to how the things line up when taking it apart, and watch out for the little steel ball that are the "click" part of the horizontal adjustment.

So after taking it apart i was left with the 2 connected PCB boards ( disconnected the LDC screen from the lot )
So i had the 1 half shell and then the plastic ring that's the other part of the horizontal click adjustment.

And so i was ready to tweak the focus after unscrewing the lens and cleaning up the thread on it.
But as this focus shifting was heat related i wanted to warm up the camera to 80 degrees according to the on screen temp gauge.
So under the camera now hanging on the HDMI wire in my livingroom window i put a hair dryer borrowed from my M8 ( we use that one to flash dry paint when we paint bodies for RC cars and so on.

But as it turned out that dryer must put out a almighty amount of heat cuz parts of the plastic shell and the ring still attached to the PCB melted/warped a little and the camera even did what i assume must have been a temperature safety shutdown.
But i just resat the camera by pulling the power and plugging it back in, and then not getting preoccupied by the damn computer.
So when the temperature reached 80 degrees i tweaked the focus and then put a drop of glue on the lens/mount to secure it from moving unintentionally.

So the camera got a little cool down period, after which i assembled the camera again, but due to the partly melted parts i have lost some of the horizontal click adjustment, so i had to flip the camera to the other side of my rear view mirror, and so it is now out of sight from my driving position.

And then i whent for a drive with the heater in my car at full tilt, and by doing so i was able to get the camera up to 70 degrees, well over where the focus shifted as the camera came from MEG.

And so i have grabbed 2 pictures from my drive, the first one parked at burger king the temperature was 68 degrees, and the other one are grabbed as i was close to home ( 0906 temperature unknown here )
And then off-course the same situations from my SG9665GC - V3 to use as a baseline.

 

[Nigel]

They look good, but what does it look like when cold now that it is adjusted?

Sometimes there is too much sharpening for my liking, most of the image is fine, but sometimes it overdoes it:

 

[kamkar]

Getting a burger to go at burger king dident take long so camera was probably still warm when i set off for home with my burger, and i am quite sure by this time on my way home the camera would be above the temperature that made focus slide before.

I am not sure how it looks when cold, i can first see that Tuesday as tomorrow also have some sun to offer, at least after noon when i am awake i i am lucky to fall asleep some time tomorrow around 09 - 10 in the "morning"

Image sharpening are indeed a dual edged sword.

Off course i could go retrieve the camera in my car and then put it in the fridge to cool it down to 10 deg or so temperature, but not today but the chance are there tomorrow.

I am not too bothered if there are a little blur when cold, the camera heat up in no time anyway, only deep winter might be a issue.

 

[Nigel]

I am not too bothered if there are a little blur when cold, the camera heat up in no time anyway, only deep winter might be a issue.

I think that even in winter it is going to reach 40C fairly fast so that is the temperature I am really interested in, but 20C would also be interesting. If it is in focus from 20 to 80 then clearly they were focused wrong, if it is now only in focus above 60 then they were focused at the wrong temperature.

I'm guessing it is best to focus them at around 60C but I will wait and see what yours looks like at 40 before I take mine apart...

 

[kamkar]

Okay i have just been out on a drive and focus seem to remain good.

I now have the 0906 on the computer table, i will fab up a way so that i can plug into it quick and have the aim be good, then i will put the camera in the fridge and cool it down to 5 degrees or so, then take it out quickly transfer it to my window sill and then start recording.

 

[kamkar]

Okay i have changed my approach 🙂

Right now the 0906 is recording the front of a SG user manual with a LED flashlight for light, all of this go on inside my fridge now ( i think it are set to 3 - 5 degrees temperature )
I cant do the same in my freezer as it are too small.

In 30 - 60 minutes i will go stop the camera recording so it have no internal heat source going, then let it really cool down for another hour or so, and then move it to my nice and toasty window sill for some recording there as it heat up on its own and aided by the little sun we have to day ( at least right now we have )

 

[Nigel]

Don't get it too cold or it will get covered in condensation when it comes out!

 

[kamkar]

Just stopped the camera recording, both it and the LED flashlight was nice and cold ( only low output on Flashlight )
Sadly the camera can not embed the temperature readings in the footage, that would be so nice at least at this stage of things.

 

[kamkar]

Yeah there might be some condensation issue in the up coming cold -> warm test in the window sill, but i will just let the camera run thru it sort of like it would on a cold winter day when you start your car up.

 

[kamkar]

Okay the camera are now recording in the window sill, started off at a temperature of 19 degrees and it is now 43 degrees.
I will let it record until it get as warm as it can ( open window so not to film thru my dirty windows )

 

[kamkar]

Okay test done.

And as i expected then the focus shift are now there when the camera are cold, just have a look as these pictures grabbed at the start of every 3 minute segment.
The starting temperature according to the LCD reading was 19 Degrees C.

So as you can see it do take the camera a little while to get up to operating temperature / operating focus.
So i think it is safe to say MEG and @Rayman.Chan have some things to look at before pressing the go button.

PS. As you can see by the times in the footage when you take the camera off the mount, then it reset and use the default time/date as a starting point

Also a funny thing about this recording, first i recorded a hour in my fridge, tneh i recorded some time in my window sill, but the files on the SD card are alternating, so first i have 3 minutes from the fridge, then i have 3 minutes from my window sill,,, and vise versa.
Clearly as i shut down the camera in the fridge it resat once again, and so my window sill recordings are almost with the same time stamp, and so the files from the 2 sessions alternate on the memory card.

I would assume the camera was supposed to backup its internal timer after the GPS time, and then keep that time if used off the mount ( not that many people would use the camera off the mount ) so maybe this also relate to the date/time reset reported by some testers.

 

[Nigel]

Mine is not great at normal working temperature, it's almost perfect at 20C internal temperature.

I also have a problem with the CPL filter. I can see the CPL filter in the left top and left bottom corners, it's fine in the right corners though. I can't move it enough to get it out of the image. There is a lot more of it in the bottom left where the lens is most out of focus, the CPL appears to be centred on the lens so presumably the sensor is not centred on the lens? Seems a bit strange.

I've also noticed that the fisheye seems to make everything curve upwards towards the sides, I'm a bit puzzled by this, maybe I need to point the camera up a bit?

Also in this image it is a bit blurred, not just from the focus but also from lack of bitrate. For some reason the bitrate in this file is only 14.8 Mb/s. This is not enough for a good quality 1080 video in good light conditions while moving quickly, it should be minimum 18 Mb/s, preferably a bit more.

 

[reverend]

I'm guessing that's the 0806 CPL?

Maybe they're tooling the 0906 CPL to be slightly larger - you've reminded me I need to try and find mine from storage as it will help with the reflections I get currently.

With the focus going out at one side doesn't it suggest something isn't quite parallel inside as well with some of these? Certainly an interesting lens characteristic going on.

We had an interesting test of the microphone yesterday - I need to see if the 0906 picked it up 😀

 

[lacibaci]

I also used 0806 CPL in my tests:
https://dashcamtalk.com/forum/threads/compare-with-sg9665gc.28804/
No problems that I could see.

 

[reverend]

I just dug out the one I had with the 0806 sample and it was a 24mm magnetic CPL and I get the same as @Nigel with the vignetting with that particular CPL - I guess they changed something along the line and increased the size a bit.

 

[Nigel]

I just dug out the one I had with the 0806 sample and it was a 24mm magnetic CPL and I get the same as @Nigel with the vignetting with that particular CPL - I guess they changed something along the line and increased the size a bit.

Did you just get the vignetting on the left like mine?

I think I remember them making some changes to the 0806 CPL after ours were made, did they shorten them a bit?
But still, it should be centred, something is not right if the lens is not centred on the sensor.

 

[lacibaci]

I used this one:
https://www.ebay.com/itm/321978593915"design & made by MEGtech"

 

[Viking]

Here is a still photo and speed = 0mph from my camera. Temperature of the housing is 72C. Left side is not good.🙁

And lot of reflection from dashboard show up. The very dark blue color is from my tone of the windshield.

Viofo A119S incl. CPL lens.

 

[reverend]

Did you just get the vignetting on the left like mine?

I think I remember them making some changes to the 0806 CPL after ours were made, did they shorten them a bit?
But still, it should be centred, something is not right if the lens is not centred on the sensor.

Definitely on the left side and potentially a bit on the right too - the test video didn't work as the camera didn't shut down cleanly again so the files were corrupt - I need to do some more testing with different chargers in case something is at play there.

Will get some video footage in the day tomorrow and see how it looks with the CPL to see if there's anything on the right as well on mine 🙂

 

[Nigel]

Some strange bitrates, spends a lot of time at only 12Mb/s, for most of the 12Mb/s I was doing around 110kph: