Need help calibrating Audi autoliv night vision camera

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Hey guys I need some help my 2013 Audi a6 night vision camera got water damaged (failed gasket) after extensive cleaning and soldering is back to working order only thing left to do is I need to manually set the focus distance anyone knows how far the focus is at its best?

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This is what picture looks like right now nothing is actually sharp my confusion comes from Audi uses a heating element to “calibrate” however that element is an X placed 1.2m in front of the camera and it has nothing to do with the mechanical focus on the lens. According to Audi specs camera sees and recognize people between 10 and 90 meters my idea is setting it up at the middle 45m or am I wrong?

[Fraser]

Are you familiar with setting the Hyperfocal point of a fixed focus camera ? This is what you need to set on your camera so that targets remain in focus at infinity and provides the best minimum acceptable focus distance as well. I would expect the camera to be capable of an acceptable focus from 0.5m to infinity. A Hyperfocal focus setting for 1.0 metre sounds about right. Hence the Audi test chart being positioned at 1.2m for testing and focus setting. I suggest you focus the camera to provide decent focus of a target at 0.5m and then check the image focus for a target at a decent distance, say around 20m. Infinity focus is a little harder to check due to the low resolution of the camera making small targets indistinct. Try looking at a building a long way away for the infinity focus check.

Fraser

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That does make sense but with normal photography background the lens been f1.1 means a very shallow focus range if it was f11 that would make longer in focus range. Audi placing heat element in front of the car at 1.2m I think is only to determine distance and software to scale pedestrian Audi will not mess with the focus ring since that’s inside behind the heater of the protective glass the picture I am attaching is before the water damage and u can clearly see the buildings are more in focus then right now

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Are you familiar with setting the Hyperfocal point of a fixed focus camera ? This is what you need to set on your camera so that targets remain in focus at infinity and provides the best minimum acceptable focus distance as well. I would expect the camera to be capable of an acceptable focus from 0.5m to infinity. A Hyperfocal focus setting for 1.0 metre sounds about right. Hence the Audi test chart being positioned at 1.2m for testing and focus setting. I suggest you focus the camera to provide decent focus of a target at 0.5m and then check the image focus for a target at a decent distance, say around 20m. Infinity focus is a little harder to check due to the low resolution of the camera making small targets indistinct. Try looking at a building a long way away for the infinity focus check.

Fraser

Also the camera has really narrow field of view so at 1.2m all u can see is about the license plate of the car in front of u I am not sure there is a point to that to be on focus

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Are you familiar with setting the Hyperfocal point of a fixed focus camera ? This is what you need to set on your camera so that targets remain in focus at infinity and provides the best minimum acceptable focus distance as well. I would expect the camera to be capable of an acceptable focus from 0.5m to infinity. A Hyperfocal focus setting for 1.0 metre sounds about right. Hence the Audi test chart being positioned at 1.2m for testing and focus setting. I suggest you focus the camera to provide decent focus of a target at 0.5m and then check the image focus for a target at a decent distance, say around 20m. Infinity focus is a little harder to check due to the low resolution of the camera making small targets indistinct. Try looking at a building a long way away for the infinity focus check.

Fraser

I am not saying u are wrong I am trying to understand it the lens states f1.1 “operational” range is 10-90m but not at 10 or at 90 I have good focus is definitely not horrible but not what it use to be

[Fraser]

Good point. I am more used to wider angle lenses with huge depth of field. If your Autoliv camera is higher power then it’s minimum focus distance could well be 10m as found in similar Thermal CCTV cameras with narrow FOV. The positioning of the Audi test target at only 1.2m then raises questions as a test target should be in focus for tests. Sorry I cannot help more.

Fraser

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Good point. I am more used to wider angle lenses with huge depth of field. If your Autoliv camera is higher power then it’s minimum focus distance could well be 10m as found in similar Thermal CCTV cameras with narrow FOV. The positioning of ten Audi test target at only 1.2m then raises questions as a test target should be in focus for tests. Sorry I cannot help more.

Fraser

Or maybe you are right it’s a 19mm lens but idk the sensor size judging by the picture I am attaching at 1.2 m the lines look not that blurry but then that’s a specific temperature element that might always look that way

[Fraser]

The camera is basically a TAU so TAU documents can help you.

Select the Tau 336 19mm lens option in the drop down lens on this page and the specifications at the bottom of the page will tell you the Hyperfocal distance that is factory set on a 19mm lens TAU. It is 9.5m.

https://www.flir.com/products/tau-2/?model=46336019H&vertical=lwir&segment=oem

More on the TAU Hyperfocal distance…..

https://flir.custhelp.com/app/answers/detail/a_id/4168/~/flir-oem---tau-2-hyperfocal-distance-and-hyperfocal-depth-of-field

Fraser

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The camera is basically a TAU so TAU documents can help you.

Select the Tau 336 19mm lens option in the drop down lens on this page and the specifications at the bottom of the page will tell you the Hyperfocal distance that is factory set on a 19mm lens TAU. It is 9.5m.

https://www.flir.com/products/tau-2/?model=46336019H&vertical=lwir&segment=oem

More on the TAU Hyperfocal distance…..

https://flir.custhelp.com/app/answers/detail/a_id/4168/~/flir-oem---tau-2-hyperfocal-distance-and-hyperfocal-depth-of-field

Fraser

I cannot find info u are refuting to about the 19mm lens however the second link you provided about the 25mm lens it says: “ For example, for the Tau 640, 25 mm f/1.1, 25deg:
Hyperfocal Distance = 21m
Hyperfocal Depth of Field = 11m
 
This means that when this Tau 2 core is focused at a 21m, object between 11m and infinity will be in good focus.”

But idk how that translates since my lens is 19mm f1.1 but they go forward to 21m absolute focus to have 11m on focus

[Fraser]

You can see the technical specifications by clicking on the full specification button on the first paged I linked to.

For the 336 TAU core with 19mm lens, the Hyperfocus distance is 9.5m and the Hyperfocus depth of field is 4.8m.

Fraser

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You can see the technical specifications by clicking on the full specification button on the first paged I linked to.

For the 336 TAU core with 19mm lens, the Hyperfocus distance is 9.5m and the Hyperfocus depth of field is 4.8m.

Fraser

Oh I see I will set it up on 9.5-10m and check what it looks like