The Lenses used in all dashcams to my knowlege is Fine M12 thread, it is allso what actioncameras like gopro - sony and others use.
Normally the lens is secured with a little glue so it dont move in the thread, and it seem most ppl have no problem removing the original lens when they want to try a after marked lens.
Some of the sockets / mounts the lens secew into allså have a screw to keep the lens in place, this is the case with the little mobius action/ dashcam and allso most IP / cctv cameras that use the small M12 lenses.
A pic of a M12 lens, and this one seem to have been fitted with a aftermarked IR cut filter ( the square glass on the end of the lens )
It is this way i hope to be able to install aftermarked IR cut filters on megapixel lenses that is not born with that filter. ( megapixel IP cameras and other megapixel cams like some webcams )
Another lens witch seem to have been born with a IR cut filter.
A pic of a couple of M12 sockets
You have to be carefull getting the right one, it seem the distance between the 2 screws that hold the mount to the PCB around the CMOS chip can vary in size.
The CCTV ones i have lying aroound seem to be around 2 mm bigger between the 2 holes than the action / dashcams i have taken apart.
The mounts can be plastic or metal, the cheap plastic ones used in some dashcams seem to go out of focus when exposed to high heat in the summer.
Focussing the new lens on the camera is best done via a AV or HDMI out on the camera.
But you can allso do trial and error focus by turning the lens "a little" move a hand in front of the camera ( to have a easy to tell part between each ajustment step ) and then turn the lens a little again, i use to do this while recording and then do 5 ajustments before i stop.
I then preview the footage and see if i at any of the 5 ajustments have hit the sweet spot, or if i need to proceed screwing the lens further in or out.
If i have hit the sweet spot in lets say 2 ajustment, i just have to turn the lens back 3 x "a little", and then do a test recording to see if i am in the sweet spot again. ( i normally ajust 2 mm on the circumference of the lens in each step )
I found a link to a aftermarked IR filter, with a cuple of guides / how 2 regarding cmos install / uninstall.
http://www.securitycamera2000.com/p...s-Optical-Low-Pass-Filter-For-CCD-Camera.html
Here is a pic of a analog bord cctv camera, here you can see where the mount go / fit around the CMOS chip.
I have just googled the 4Sight Dash Cam camera, and the consept seem valid, but thats allso it ( for the following reasons )
1. Dashcameras with IR light build in are allways bad, and the IR light will reflect in the window blinding the camera at night.
And even if that did not happen the ammount of IR light ermitted is low, so it will not reach longer than the end of the hood on your car. ( at best )
2. the 4sight cammra i looked at seem to stitch the 2 feeds together to 1 video file ( of unknown resolution )
you should have 2 seperate videofiles, and they sould both be in 1080P resolution.
I think if you are in the Markus M5 prize range, you should have a look at the powerucc panorama X2. the Markus M5 lagged in night performance with the last footage i saw from one of those.
