lens experiments ( 12 mm ) long range dashcam

This brings up a question, what should a good IR lens cost for the M12 type lens and where do you get good ones? Like I said before, the ones at M12lenses.com are under $3.00. I just have a hard time thinking $3.00 get's one a good IR filter.
I'll let you know about the $3.00 filters tomorrow - I ordered 3 of them.
BTW, I think it's not cheap $3.00 for 8mm x 8mm glass :)

I have one question though, does it matter which side faces the sensor?
 
hehe yeah imaging having your house windows with glass like that, and here you are sort of forced to do that as only high insulated glass are allowed for windows, so at least 2 layers of glass.

The car from yesterday demoing how not to install stuff on windscreen.
 
I'll let you know about the $3.00 filters tomorrow - I ordered 3 of them.
BTW, I think it's not cheap $3.00 for 8mm x 8mm glass :)

I have one question though, does it matter which side faces the sensor?

Actually I don't know either, The only filters I've bought for cameras were for a Nikon Fa 35mm . And those filters were not cheap, special glass and coatings that only go on one way, I believe like dashmellow discussed several posts up.

Good luck on the lenses, I'm especially interested in the 8 and 16mm ones you bought. Looking forward to your review
 
Well, my experiment was kind of a bust. Out of three lenses (3.6mm, 6mm and 16mm) I was able to test drive only with 3.6mm.
The 6mm turned out to be too short (I'd have to use one of the barrel extenders)
Another problem were the IR cut filters which turned out to be too big to fit at the end of the lens.
In the end I found an old M12 lens with IR filter that I could remove and fit on my 3.6mm.
The 3.6mm makes the FOV almost 90 degrees which I liked very much. There is definitely more detail comparing to 120 or 155 degree lens.

JVX with the original lens (155 deg.)

JVX with 3.6mm lens (~90 deg.)

SG V2 (135 deg.?)

Raw video for all three:
https://mega.nz/#F!dtYCwZbB!qlhyZHnFBrYvu3Dt5dWHng
 
Yeah, I noticed that. I thought I cleaned all lenses before and after focusing.
Not sure if it was from the IR filter or the front of the lens.

It's an optical flaw of some kind, not a dirty lens. Are you able to tell if any of the other lenses do anything like that?
 
The original JVX lens is ok. The 16mm one doesn't have an IR filter so I couldn't really test it. I still have the 6mm one but need an extender... Got them all from m12lenses.com
 
This issue is happening as a result of sunlight directly entering the front of the lens from an oblique angle. It appears to be a diffraction rainbow not unlike the rainbow effect you might see on a DVD surface. My theory at this point is that you received a defective lens or it may just be a cheap low quality, poorly corrected lens regardless of what you paid for it. "Maybe" it's the IR filter but it seems to be happening on a front lens element. If you can test it in those conditions without the IR filter you might gain some knowledge. I would suggest emailing my screen shot to M12lenses.com and see what they have to say about it.

EDIT: I guess it could be grease on the IR filter from a finger print but I've not seen anything quite like that before. Another theory is the front of the lens might have bad swirl scratches from cleaning.
 
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The lens work just as fine as any other usable lens, if have a F1.6 value so it let thru a lot of light.
And yes the HDMI on the X cam sure are nice when setting up a new lens.

@kamkar1 I have been trying to find a quality 12mm f1.2 or 1.4 lens but haven't been able to find either, then after reading the above comment of yours I contacted Peau and asked them if their was any problems with using that lens (12mm, f1.6, 2 Mega Pixels) you bought in a Mobius 1 camera, I asked because the Mobius 1 camera sensor has a resolution capability of 3.4 MP, so the lens should have at least that MP value or more. Peau answered my email and told me NO, not at 100%, because the camera was able to resolve 3.4 MP but the lens only delivered 2 MP.

Please don't shoot the messenger, this is what they told me. I answered some questions he had and they are checking into finding me a good lens. When and if they answer I will relay the response back to you guys. I also contacted another company that is supposedly one of the major lens manufactures in China, asking for the lens, however companies over their seem to have difficulty answering back, we'll see.
 
This issue is happening as a result of sunlight directly entering the front of the lens from an oblique angle. It appears to be a diffraction rainbow not unlike the rainbow effect you might see on a DVD surface. My theory at this point is that you received a defective lens or it may just be a cheap low quality, poorly corrected lens regardless of what you paid for it. "Maybe" it's the IR filter but it seems to be happening on a front lens element. If you can test it in those conditions without the IR filter you might gain some knowledge. I would suggest emailing my screen shot to M12lenses.com and see what they have to say about it.

EDIT: I guess it could be grease on the IR filter from a finger print but I've not seen anything quite like that before. Another theory is the front of the lens might have bad swirl scratches from cleaning.
This was more or less just an experiment for me. I was not going to use this as a full time camera anyway (it's JooVuu...)
I just wanted to find out the sweet spot for FOV. For my eyes, anything above about 100 degrees doesn't have enough detail at 1920x1080.
 
This was more or less just an experiment for me. I was not going to use this as a full time camera anyway (it's JooVuu...)
I just wanted to find out the sweet spot for FOV. For my eyes, anything above about 100 degrees doesn't have enough detail at 1920x1080.

Fair enough, but it would be interesting and certainly useful to understand what is going on here. Is M12lenses.com selling crap lenses? Did you receive a defective one? Could you have accidentally compromised this lens in some manner?

One way or another this is a serious optical defect that is compromising what you can see in front of your car and it is manifesting for a significant length of time in your video for the entire time the sun is hitting the front element of the lens from an oblique angle. The question of the chosen FOV having enough detail or not becomes a moot point.
 
@kamkar1 I have been trying to find a quality 12mm f1.2 or 1.4 lens but haven't been able to find either, then after reading the above comment of yours I contacted Peau and asked them if their was any problems with using that lens (12mm, f1.6, 2 Mega Pixels) you bought in a Mobius 1 camera, I asked because the Mobius 1 camera sensor has a resolution capability of 3.4 MP, so the lens should have at least that MP value or more. Peau answered my email and told me NO, not at 100%, because the camera was able to resolve 3.4 MP but the lens only delivered 2 MP.

Please don't shoot the messenger, this is what they told me. I answered some questions he had and they are checking into finding me a good lens. When and if they answer I will relay the response back to you guys. I also contacted another company that is supposedly one of the major lens manufactures in China, asking for the lens, however companies over their seem to have difficulty answering back, we'll see.
The Mobius 1 has a 2304x1536 sensor. However the 1080p video output is achieved by taking a sample from that sensor. It is not a crop from the centre. Essentially the larger resolution is resized down to 1920x1080. Therefore I do not think there would be much to gain by using a lens rated higher than 2mp, as the camera literally throws away the extra pixels when downsizing each frame.

If you want to use the mobius with a telephoto lens for photos at the native 2304x1536 resolution then you would indeed benefit from a 3.4mp or higher rated lens.
 
The 2 MP lenses i have tried on my mobius have worked just fine.
the x cam are also a 4 MP sensor as its the OV4689 sensor also used in so many dashcams.

Its more if you take a 16 MP action camera and put a 2 MP lens on it, that would be bad, and also why peau dont have "my" 12 mm lens in the segment lenses for the newer action cameras.
The other way around dont really matter aside for it is overkill to put a 16 MP lens on a 2 MP camera, but that way around at least there should not be any nasty surprises in the footage.
 
The Mobius 1 has a 2304x1536 sensor. However the 1080p video output is achieved by taking a sample from that sensor. It is not a crop from the centre. Essentially the larger resolution is resized down to 1920x1080. Therefore I do not think there would be much to gain by using a lens rated higher than 2mp, as the camera literally throws away the extra pixels when downsizing each frame.

If you want to use the mobius with a telephoto lens for photos at the native 2304x1536 resolution then you would indeed benefit from a 3.4mp or higher rated lens.
On reflection I'm not entirely sure that what I said is true! If you have a 2MP lens projecting onto a 3.4MP sensor, it is probable that the entire image will be a bit soft. Downsizing that soft image to 2MP by pixel-binning will not necessarily improve sharpness. However evidence from others that 2MP lenses are fine is good enough for me.
 
I had a pleasant chat today with a friendly and knowledgeable guy at SeeSense here in the UK. He's going to locate some 8mm and 12mm lenses for me :)
Nearly fell off my chair tonight. Just received a quote for this 12mm f1.6 2MP lens from a UK supplier. How much? £90!!!! :eek: (n)
 
no wonder he was friendly :eek:

You have to be very careful when talking/email with these people because one never knows if they are honest or not! I've emailed lots of companies in China recently and had some real problems that could have defeated what I was trying to accomplish if I had went with them. First off most of them don't speak english (and I don't speak Chinese) so they have intermediary's (english speaking) that answer your emails. They don't necessarily know anything about lenses so you get my drift !
Example: One company had just what I wanted till I got the Lens specifications sent to me. When I went through the specs I came to focus = 100 to 200mm, what the heck, that's a macro lens!

Just be very careful, and if you aren't sure request the Spec sheet on the lens and have someone look at it who knows what they are seeing (better then me). If you decide to buy have an agreement written up on your options if you want to return it for a full refund. Also, just because someone wants xxxx$$ for it, make an offer!

Forgot to say because I just saw that it was a 2 Mega Pixel lens.
Most, if not all camera sensors in today's world have at least a 3.5 Mega Pixel capability (Mobius 1 for instance) if they are any good at all. If you put a Lens on a camera with less MP then the camera it will not work like it should, in short, the camera can handle more then the lens can deliver.
 
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