lens experiments ( 12 mm ) long range dashcam

kamkar

Well-Known Member
Joined
Oct 11, 2013
Messages
34,224
Reaction score
18,873
Country
Denmark
Dash Cam
10 years, many dashcams
So my new and expensive 12 mm lens arrived today ( thank you Danish customs for doubling price and adding a week to delivery time )

So needless to say i hurried up getting the lens into a camera, and again the choice fell on the Joovuu X camera as a test platform.

So for your viewing pleasure i have stitched 2 feeds together, one from a normal dashcam, and one from the lens modified camera.

I do have to redo focus and figure out how to better secure the lens as it dont thread much into the base before it is in focus, so right now it is a somewhat wobbly setup.

 
Last edited:
well its really pinnacle studio 20 doing the work :D

I just drop 2 videos on each line in the editor, then highlight one of them and remove top 25% then remove bottom 25% and then move the remaining 50% of the footage either 25% up or -25% down.

Take much longer to render and export than me setting up the parameters for the software :)

Tweaking the percentages you can compensate for 2 cameras not being the exact same alignment, this do add a little more time to the process.
But here thank to the vast difference in the 2 lenses i dident have to do any tweaking.

I do like this lens, if you pause in the start of the movie where we drive slowly down Aarhus road towards the City center you can actually see on the bottom footage that if some one had run out in front of cars way up ahead, you would actually get a okay recording of that.
Where as in the GC wide angle footage that would just be a few pixels in the background moving.

Needless to say one need both kind of cameras as you can also determine by the footage, but i think its alright, when a oncoming car go out of view on the 12 mm lens its just about where it get good into view on the wider angle camera.

So i think its win - win with a long lens camera in the car.
 
Last edited:
I like the new "zoomed" look of your video with 12 mm lens,great job @kamkar1 .:)
 
yes me too, no hiding out in front of me.
And as you know with a regular camera out front dont really have to be that far off in the distance.
And being stopped behind a car its almost like crawling into the car in front :D
 
But i wouldn't recommend any one go larger than this 12 mm lens, but 8 mm are also nice i just wanted to try something new, and so far i dont think its too much zoom.
 
For short distances maybe a half smaller lens would be just enough "zoomed", beacuse when you are too close behind car its look like you are inside of it.:eek:
Which kind of lens you used (12mm), are they universal for most of dashcams, is there any choice of different mm lenses? So much questions I have, you interested me in those lenses very quickly or am I just too curious.:D;)
 
The lens are normally used in CCTV cameras, so its just fitted with a IR filter ( will take some pics of the lens and post here later )
Its the same M12 fine thread they use ( action cameras / dash cameras and many CCTV cameras ) but some CCTV cameras also use a larger ( physical size ) lenses around M20 fine thread, these are called C or CS mount lenses and do not fit a dashcam.
I paid 40 dollars for this 2 megapixel lens.
 
IR cut filter.
l3.jpg

Side view.
l1.jpg


Front view.
l2.jpg
 
But i wouldn't recommend any one go larger than this 12 mm lens, but 8 mm are also nice i just wanted to try something new, and so far i dont think its too much zoom.

WOW KamKar1, that is really impressive, even if one had to use 2 cameras, you can get what the courts want! If there was only some way to do that with one camera you would be a very rich man. This is one of those times in life that I wish I knew a lot more about cameras then I do. I don't remember whether you said or not but what does a lens like that cost, maybe even one in 8 to 10mm would be a tremendous improvement over a normal/regular dash cam. I sure hope you are not finished working with this project:cool:(y).
 
I have been sort of asking for a dual camera but with both lenses pointing forward, but one then being a 8 - 12 mm and the other one a regular for the wider perspective.
I would snag such a camera up in a heartbeat.
 
WOW KamKar1, that is really impressive, even if one had to use 2 cameras, you can get what the courts want! If there was only some way to do that with one camera you would be a very rich man. This is one of those times in life that I wish I knew a lot more about cameras then I do. I don't remember whether you said or not but what does a lens like that cost, maybe even one in 8 to 10mm would be a tremendous improvement over a normal/regular dash cam. I sure hope you are not finished working with this project:cool:(y).

You can find some cheap lenses on AliExpress - they may not have the best optic quality, but it doesn't bother me as I use it as a secondary camera anyway. I has to mount an IR cut filter myself though, as I couldn't find any pre-installed.

I have been sort of asking for a dual camera but with both lenses pointing forward, but one then being a 8 - 12 mm and the other one a regular for the wider perspective.
I would snag such a camera up in a heartbeat.

Your original experiments with the 8mm lens caused me to do the same with my Mobius. Now, I can't imagine not running two cameras up front - widelens to capture all the action, and a "zoomed" camera to capture more details directly in front of the car. A dashcam that had this natively? I'd be very interested as well.
 
Yep the little IR filters you can buy and put it on yourself,, they come in both square and round models, and i also assume there is a size or two.
I wouldn't go too cheap on the lens, at least make sure it is a megapixel one but off course it dont have to be a 2 digit megapixel one, most dashcams are just the 2 megapixel it take to make up 1080p footage.

If you have windscreen real estate to spare and have gotten a new camera, then this little mod are a nice way to keep using the old camera.
I would also like a similar camera in the back, but due to sky often reflecting in the windscreen of the car behind a CPL filter is a must.
 
I have been sort of asking for a dual camera but with both lenses pointing forward, but one then being a 8 - 12 mm and the other one a regular for the wider perspective.
I would snag such a camera up in a heartbeat.

What about fashioning a dual lens head instead of just 1 head lens or would that cause some kind of interference in the sensor?
 
The sensor will just relay whatever hit it, but a lens with 2 different sizes in it would be a tough mechanical exercise i think
 
Imagine taping two Mobius or X's together, affixed to the bottom of each other - one with a standard lens and an 8mm or 12mm lens.

Love your video Kamkar, would have never thought to present it that way.
 
I think its the way to do it, people just have to realize that in truth its just 2 half videos they see at least when it come to the vertical aspect.
So there is a bit more to the footage's than seen above, but the main concern i think with a larger lens is how much you loose to the sides, and with a 12 mm lens that is indeed a lot so would be a totally useless stand alone solution.

Maybe i should UL a clean segment of the 2 steams too so people can see the full uncut picture.
 
The first part of the video, just the uncut footage from the 12 mm camera.

My friend have called upon my help today, so i will have to take a drive tomorrow, but this should give me some footage where i dont need to have the wiper going most of the time.
If i am lucky i might even see the sun thru a hole in the skies above.

PS. looking at the footage i am sure you too will get the " O no he is going to ram that car" feeling

At 0:45 i wave my finger in front of that camera, that's to indicate at this time i was not able to read the plaate of the #2 white car in front of me with my eyes, i estimate the distance then to be 20 - 25 M
 
I do have to redo focus and figure out how to better secure the lens as it dont thread much into the base before it is in focus, so right now it is a somewhat wobbly setup.

[/MEDIA]
That looks really great @kamkar1! Too bad about the thread problem. When purchasing an after market lens it's really important to confirm the back focal distance (The distance from the rear element of a lens to the focal point.) Peau usually lists the back focal length but apparently didn't on this lens. I see it just says N/A.

One thing you could try is swapping in a different, deeper M12 threaded lens holder on the sensor for the JooVuu. That's what I did for the 2.8-12mm varifocal lens install on the Mobius. Another option might be to install an extension ring onto the existing M12 holder.

Depending on the module that's in the JooVuu you can probably swap the holder. They are usually sold according to thread depth and the distance apart of the two screw holes. A longer, deeper threaded mount should fix your problem.
m12wholder.jpg

One of these extension rings might work but I've never used one so I can't speak from experience.

extension_ring.png

This link has a variety of different size and depth M12 lens mounts for sale.

http://www.m12lenses.com/M12-Lens-Holders-s/61.htm
 
Last edited:
Back
Top