Low light performance wide angle Vs narrow angle lens

kamkar

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10 years, many dashcams
So for a while as you might know i have been on and on about my x camera fitted with the 8 mm lens, and i have claimed i feel like the chance of capturing a plate in low light ( not darkness ) is higher with the 8 mm lens.

So to backup my claim i have been compiling a little footage to prove my claim.

First off the raw stuff.

The wide angle footage is from my mobius 2 camera and it too record in 1080/60 and the bitrate is 25 mbit

Yeah i know the mobius 2 is a new cam and it need improvement, but i an quite sure if i was to go to my car and get the footage off my SG9665GC the number of plate captures will be no or only little better.
At this stage its not so much about the camera i think, plate capture even on the best performing dashcams is a pain in a situation like this.

The narrow angle footage is off the x camera fitted with the 8 mm lens, dont have the specs on that lens but its a whole lot more narrow than any wide angle camera.
The camera is recording in 1080/60 too and the bitrate is 18 mbit.

yes i know 25 and 18 mbit is not the same but with the latest x-cam august 16 ( beta firmware ) that's what high bitrate setting give you.
On the other hand the 25 mbit of the M2 camera is from the low setting ( 3 lowest bitrate setting in the GUI )

If we was to be anal about i should have run the M2 with the highest bitrate setting just like the x camera, but that would widen the bitrate even more, and i am a nice guy and the M2 is not a bad camera so it can hold its own.

Anyways both cameras use H264 and newest firmware's, in the case of the mobius 2 that's the newest beat driver not really available to the general public.

So first the 2 recordings after movie maker and youtube have done all they can to ruin otherwise okay footage, this means the footage is only 30 FPS here and so on.


So for you here is the 2 raw clips, only cut down to size using registrator viewer.

https://mega.nz/#!z8YF3RKL!bM3dv9x3KzopeaP7nKcpiF-DzjspGo72FotbedzLHAA
https://mega.nz/#!7s5SnIrb!FX_W1wrdBwyzgDC9UazAaNzZBIiG1IILOn_3T4kXn0w

Yeah i know even with the 8 mm lens some of the cars are almost not readable, but in the M2 footage they are just a blur, at least the last handful of cars.

I still think there is something to my claim, so until some one can proof otherwise i will remain a fan of a secondary narrow FOV camera in the windscreen for those low light situations, and trust me there is a lot of those for any dashcam anywhere in the world.
 
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I agree, the 8mm lens on the x definitely improves plate reading ability. Did you install the 8mm lens yourself on the x?

I'd be interested in looking at this myself with either an Innov C2 or Mobius B lens I have laying around right now. Any tips?
 
Yeah it was a lens i had lying around.
The swap was easy, but for the most you will need a firm grip and some force to break the bond of the factory glue on the original lens.
I was able to grip the lens base in the camera shell with one hand and then get a grip on the lens itself with some pliers ( off course with some cloth in between so i didn't damage the nice x camera lens )

The lens i am using is also a fairly cheap one, i am sure a better one would give even better results, but so far i haven't jumped the gun on a better megapixel lens cuz they are not cheap and my money are tight at the moment.

If only the area was covered by the wipers i would move that x camera all the way to the left in my car along the A pillar

I think the Innovv C2 is using smaller 8-9 mm thread lenses, i know my C1 was a lens like that, but the mobius is a regular M12 fine thread lens for sure.
Besiden the innovv cameras are a pain to take apart and get back together, and in that regard the mobius is a walk in the park.

I think this 8 mm lens and the 90 degree lens from my innovv C3 ( also M12 fine thread ) have also been on my old mobius B lens camera at one time.
But innovv C1 - C2 and C4 i fear is using the smaller 8-9 mm thread lenses.
@RockThinking might be able to confirm this ?

Mobius is nice to work with only a little grub screw holding lens locked in place.
 
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It seems you're right. I do recall reading that a narrower FOV increases acuity, I think because each CMOS pixel then covers less lens area or something. You still need wide enough FOV angle to capture relevant traffic so best to have two cams, and this is the perfect excuse to do that :cool: My State does not have front plates so I plan something similar in back to get as many car and face details as I can. For now a G1Wc goes back there tomorrow.
 
Mobius it is then. Was doing some reading on lenses in the forum and seems like most don't have an IR filter. BuyMobius has a 16mm and 25mm for sale - too extreme I think. I'll keep looking, I'm interested in trying it out, but don't want to spend the same price as a new Mobius on a lens.

Does the M2 have M12 fine thread?
 
True you will have to look out for that when shopping, but on the + side you can get little IR block filters to glue in the camera end of lenses that don't have it build in.
But for the most it is possible to find what you need ready to go.

Yes the M2 is much like the old one, i already had mine taken apart and its a outright pleasure to work with too.
But i did not take note of if the M2 lens is also held in place by a grub screw.

The larger lenses are often used by ppl like softball and paint ball players, stuck to their marker you will have good ingame footage of your kills.

I do have a 15 and 45 mm lens too, but i have not gotten around to try them on any of my cameras.

The prizes on CCTV lenses can be spread all over the place, but when you think about the cheap ones have plastic lenses and so on, where good ones have metal bodies and glass and lots of it throughout.
 
Any idea how the fov on your 8mm X camera compares to the A lens on my mobius?
 
No, and i have no specs on that lens, and i am not sure you can just take any old 8 mm lens and then look up the specs for that.
And my old mobius is a B lens

But i would assume the 8 mm lens is a lot more narrow FOV than the A lens mobius.
 
I just got my 8mm mounted to my Mobius. Still need to install an IR cut filter. I think the A lens is around 90 FOV? 8mm lens is around 45 FOV. I'm loving the zoom 8mm gives, much more details for objects further away. I'm using it in conjuction with a wide angle camera, and I think I love the setup.
 
Some pic examples:

SG9665GC at 112 Horizontal FOV
5f41e2a37d.jpg

Mobius w/ 8mm lens at about 45 FOV (Purple-ish tint due to no IR cut filter)
5f41c2e98b.jpg

Look how you can see the face of the person turning in the intersection.

I love having both cameras up front - wide angle camera to catch wide details, and narrow angle to better capture details right in front of the car. Thanks @kamkar1 for the inspiration!

Oh, and I'd never run the 8mm lens standalone, too narrow FOV. Notice in the image above I am 2 cars back from the intersection, and you can't see the traffic light.
 
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I just got my 8mm mounted to my Mobius. Still need to install an IR cut filter. I think the A lens is around 90 FOV? 8mm lens is around 45 FOV.
Thanks for that. I knew the 90deg of the A lens is narrower than most dashcams. 45deg is a lot smaller field of view
 
hehe yeah gotta be careful about those angles, diagonal or horizontal

I have just put a new lens on the 8 mm x camera, i have no idea what it is but i estimate it is 6 mm.

Tried a 30 mm first, but that one will need a base with a longer thread cuz it was in focus even before i tried to screw it in.

Will use the new lens for a while while i determine if the newer X cam firmware is past the hardware in that pre-production camera, cuz i formatted both that camera and the production camera at the same time, but the pre-production camera is not recording half of my drives, and i have just verified sd card is 100% okay.
 
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