A139 (Pro) Telephoto Remote Camera

[pinoyplaya4life]

There are a few 3 MP 8mm starlight lenses available now from Treeye and Yumiki that I don't recall seeing when I purchased the two different 6mm versions I own. There's a 4K 8mm available now too.(10.5 mm BFL)

Yumiki M12 CCTV 3MP 8mm lens F1.5 Focal Length 8mm Sensor 1/2.5"​

Starlight Lens 8mm CCTV Lens HD 3.0Megapixel IP Cameras Lens F1.5 M12​

4K Lens 12Megapixel Fixed M12 Lens 8mm Long Distance View 1/1.7 inch For IMX226 IMX178 4K IP CCTV camera or 4K Action Camera​

Re-reading through this thread it seems like you were the one who found the 8mm lens which you pointed out had BFL of 10.02mm. If you had some more knowledge and taken actual measurements of the camera this was going to be integrated into, you would have known that it’s going to be a ”cross your fingers” fit just looking at the specs …. if you understood what MBF meant and looked at that instead.

If you were really that experience, there would have been no need to modify the lens mount (you would have recommend a lens that fits without modifications to the mount). It would have been a simple plug and play. But look how this 8mm mod played out.
The mount needed to be modified because focus couldn’t be achieved. This could have easily been known beforehand if you used my equation (with proper measurements accounting for initial thread engagement distance and sensor thickness)

But nope. The 8mm lens resulted in trial and error (by having to modify the mount).

Like I said, trial and error is your experience.
I think I’ve proven my point.

This specific 8mm lens will not work without modification to the M12 mount (for this specific camera: A139 interior camera). You need an MBF of 6mm or less to make it work without modification to the mount (all other specs and requirements still apply). But the BFL does NOT matter.

Lens referenced is

4K Lens 12Megapixel Fixed M12 Lens 8mm Long Distance View 1/1.7 inch For IMX226 IMX178 4K IP CCTV camera or 4K Action Camera​

End of discussion.

The other lens such as this one:

Starlight Lens 8mm CCTV Lens HD 3.0Megapixel IP Cameras Lens F1.5 M12 For HD CCTV Surveillance Cameras​

….will work without alterations to the lens mount for this A139 interior camera since MBF is less than 6mm. It would be a plug and play but still needs an cut-filter.

 

[kamkar]

Over the yuears i have seen the school home work of my sisters kids, and i have seen what is asked of kids / young folks in other countries,,,,, all i can say is i am glad i went to school in the 70 / 80ties, CUZ what they do today i am pretty sure would have left me even more traumatized than i am from the apparently cake walk school was back then.

 

[TonyM]

If you’ve been working on telephoto mods for 7 years, then you’re doing something wrong. Should have been a one time thing and never looked back.

You know, some of us actually like tinkering with cameras, trying things that perhaps they were not designed for, finding out what works well and what does not. It's part of how we learn and gain experience - something that we have been willing to share with other members along the way. Even dashcam manufacturers have been interested in what @Dashmellow, myself and others have been doing and finding out.

As a result of this thread alone I've had a number of members contact me directly asking whether I thought Lens X or Y would be a good fit for the A139 remote camera.

This setup is probably not my final solution. I have ideas to install this 8mm lens in a different camera, and the A139 remote might receive a wide angle modification instead. But if that does not work out, maybe I will come back to this combination in the future.

 

[pinoyplaya4life]

Okay. Here’s some math for @Dashmellow:

I scaled it as best I can. The total length of the lens is not scaled because it’s irrelevant but does matter if you want the lens to not protrude out of the case as much.

But you can see why BFL doesn’t matter.

Also I understand that it should be measured from the vertex of the glass, but I didn’t want to show ambiguity so I showed it on the line of the glass. You can move the “glass” representation on the sketch so the vertex is right on the BFL measurement on the ruler. But it wouldn’t matter. Results are the same.

 

[pinoyplaya4life]

Hence the reason to look for a lens with 6mm or less MBF so you have 2.79mm of thread engagement minus the thickness of the sensor and when the threads actually starts.

If MBF is greater than 8.79mm, good luck mounting it to the current lens mount. It would be floating in air. You can fix this by getting a lens extender.

 

[Dashmellow]

Hence the reason to look for a lens with 6mm or less MBF so you have 2.79mm of thread engagement minus the thickness of the sensor and when the threads actually starts.

If MBF is greater than 8.79mm, good luck mounting it to the current lens mount. It would be floating in air. You can fix this by getting a lens extender.

Okay. Here’s some math for @Dashmellow:

I scaled it as best I can. The total length of the lens is not scaled because it’s irrelevant but does matter if you want the lens to not protrude out of the case as much.

But you can see why BFL doesn’t matter.

Also I understand that it should be measured from the vertex of the glass, but I didn’t want to show ambiguity so I showed it on the line of the glass. You can move the “glass” representation on the sketch so the vertex is right on the BFL measurement on the ruler. But it wouldn’t matter. Results are the same.

For a guy who has never installed an aftermarket lens in a dash cam, this is nothing more than a bunch of absurd, theoretical nonsense about how this all works.

Why don't you actually buy a lens, install it in a camera and see what happens and then report back about your experience like everyone else? .......Assuming you could do this kind of careful DIY modification without damaging the camera, You can go from there, rather that lecture everyone about your imaginary mathematical theories about optics? I mean, a week ago you had never even heard of about his kind of stuff and wanted to know about how to avoid all the sophisticated work @TonyM did to achieve what he did and instead just find a lens you could "just screw in to the camera" and now somehow you're a self appointed expert on the subject even though you have no clue about what to expect if you were to actually try to do this.

 

[pinoyplaya4life]

For a guy who has never installed an aftermarket lens in a dash cam, this is nothing more than a bunch of absurd, theoretical nonsense about how this all works.

Why don't you actually buy a lens, install it in a camera and see what happens and then report back about your experience like everyone else? .......Assuming you could do this kind of careful DIY modification without damaging the camera, You can go from there, rather that lecture everyone about your imaginary mathematical theories about optics? I mean, a week ago you had never even heard of about his kind of stuff and wanted to know about how to avoid all the sophisticated work @TonyM did to achieve what he did and instead just find a lens you could "just screw in to the camera" and now somehow you're a self appointed expert on the subject even though you have no clue about what to expect if you were to actually try to do this.

You do realize there’s a mathematical solution to this right? You asked me why I was constraining myself to a MBF of 6mm. That is the reason why. Yet you fail to accept how the math works.

You realize this is how engineers work out their designs right? Math and Physics.

But yes, I’m waiting to get my lens and will start the modification. Will post results as soon as the lens arrives from China and I get the chance to put it all together. Already found the lens I need.


What is non-sense about it? What is it that you don’t understand on the schematic I showed? Perhaps you need to learn how optics work. Just because you were able to produce results with telephoto lens does not mean you understand the math and physics behind it.

Just like how a carpenter can build a house but not necessarily figure out (or design to build) what the maximum wind speed a house can withstand in case of a heavy storm. There’s a difference between a carpenter and an engineer/architect. That’s you and I.

Also, it doesn’t take much to understand that an M12x0.5 lens wont fit a M12x0.3 lens mount. You don’t need to physically do it to know that it wont work. (just an example that you don’t need to try something to know the results).

After 5-8 years of experimenting you still don’t understand how it all works. That’s just sad.

 

[Dashmellow]

it doesn’t take much to understand that an M12x0.5 lens wont fit a M12x0.3 lens mount.

Good lord!! How clueless can you get? What the hell is an M12 x.03 mount? You don't know, of course. You don't realize it but you just keep embarrassing yourself. An M12x.05 lens won't fit an M12 x.03 mount because there is no such thing as an M12 x.03 lens mount.

 

[pinoyplaya4life]

Good lord!! How clueless can you get? What the hell is an M12 x.03 mount? You don't know, of course. You don't realize it but you just keep embarrassing yourself. An M12x.05 lens won't fit an M12 x.03 mount because there is no such thing as an M12 x.03 lens mount.

As far as I can tell at this point you appear to be just a garden variety internet troll.

Oh boy. clearly you don’t understand what I’m trying to say….. regardless if it exist or not… it wont fit.

FYI: GoPro uses M12 x 0.35 on some of their older GoPro (IIRC the 5, 6, 7). But same thing… can’t use a M12 x 0.5 lens on it.

Perhaps you should do more research?

Also you typed in 0.03 fyi…. twice… perhaps you misread it. You quoted it so you can go back to your quote and re-read.

sad life brah. who is embarassed now?

 

[TonyM]

Please can we leave lens theory to one side for a while, or preferably take it to another thread if you want to continue the debate?

 

[TonyM]

A139 Pro 4K Wide Angle and 1080p 8mm Telephoto

For a while I have wondered whether a telephoto lens on a 1080p camera offers much benefit over 4K on a wide angle camera. It is something I have discussed with @Nigel in various threads, including this one.

In the example posted 2 days ago where I was driving towards the low winter sun, there is clearly a difference in metering and exposure between the two cameras.

Taking an example with more normal lighting, I put together this compilation of the 4K wide angle and 1080p 8mm telephoto videos. Audio has been removed for privacy since I had the whole family in the car.

I then cropped the 4K video to select the central 1920x540 pixel region so that both videos are at 100%:

There are differences in metering between the 4K HDR Starvis 2 wide angle and the 1080p non-HDR Starvis 1 telephoto camera, mostly because the sky occupies a smaller portion of the telephoto video.

Admittedly, YouTube is not the best place to judge differences in resolution / detail, and the 4K video has been cropped to 100% in VSDC. For info, the 4K video was recorded at 46Mbps and the 1080p video at 16Mbps.

This example is just looking at the central 25% of the wide angle view. Remember that the 4K wide angle records this level of detail across the entire frame, not just in the middle. These screenshots are perhaps a bit better to judge the differences in detail.





Yes, of course there are differences. But are they enough to justify buying another camera, having another camera on the windshield, using more power in parking mode (2CH vs 1CH)? I like having the redundancy of a second camera, and looking at other examples there are times when the difference between these two is much greater, so I will continue using 2 cameras. However I am already thinking about installing this 8mm telephoto in a higher resolution camera.

 

[Julian23]

Yes, of course there are differences. But are they enough to justify buying another camera, having another camera on the windshield, using more power in parking mode (2CH vs 1CH)? I like having the redundancy of a second camera, and looking at other examples there are times when the difference between these two is much greater, so I will continue using 2 cameras. However I am already thinking about installing this 8mm telephoto in a higher resolution camera.

The telephoto does capture some situations better. I like it since it's brighter and more clear for the videos you showed today. But it's not that big of a difference to really need it.
The video where you drive into the low sun is a different story. The telephoto lens seems to capture a much better video there than the main camera.
For a normal person, the A139 Pro will be good enough I guess. To capture everything, the telephoto camera is without a doubt very useful.

 

[Dashmellow]

FYI: GoPro uses M12 x 0.35 on some of their older GoPro (IIRC the 5, 6, 7). But same thing… can’t use a M12 x 0.5 lens on it.

Perhaps you should do more research?

Also you typed in 0.03 fyi…. twice… perhaps you misread it. You quoted it so you can go back to your quote and re-read.

sad life brah. who is embarassed now?

It doesn't exactly take a genius to know that a M12 x 0.5 thread pitch lens won't fit a M12 x 0.35 mount. Of course, the non-existent 0.3 lens you mentioned wouldn't fit either. It's not clear what your point is here as it has nothing to do with any of this.

By the way, brah, you spelled "embarrassed" wrong. - sad life ?

 

[pinoyplaya4life]

It doesn't exactly take a genius to know that a M12 x 0.5 thread pitch lens won't fit a M12 x 0.35 mount. Of course, the non-existent 0.3 lens you mentioned wouldn't fit either. It's not clear what your point is here as it has nothing to do with any of this.

By the way, brah, you spelled "embarrassed" wrong. - sad life ?

The fact that you don’t get the point of this simple statement tells me you are incapable of understanding how this works.

You said that I “haven’t even done any mod like this and have nothing to show in terms of results but here I am pretending to know how it all works”. Not exactly verbatim but it was your point.

I don’t need to show real life results to know how it will work. You can mathematically figure it out first. Once you figured it out mathematically, then you can try it. This is how engineers solve problems. They review specs, develop their design, and analyze for form fit and function… before they go about buying or making it.

An experienced person wouldn’t have selected that specific 8mm lens without warning.

So let me ask you this. When you linked that 8mm lens did you know it wasn’t going to work without modifying the mount? If you did, why didn’t you point it out? I assume you did not realize it was not going to work out of the box since you had no idea how to utilize the specs right in front of you.

Imagine someone else buying whatever you linked because of your so called “experience” and think it would thread right in and adjusted to focus. Then it turns out it didn’t work and they have to buy an extender. But since the extender adds length, it wouldn’t work either.

Tony, who also has some experience modifying dash cams, did exactly just that. Luckily he has some experience that he was able to fix it and replaced the lens mount because it wasn’t just a matter of plug and play.

But if it were anyone else, they would have wasted $$ purchasing a lens that wouldn’t work for this specific camera. The solution Tony worked with would be too much modification for anyone new that they could damage their camera if they tried the same thing.

But hey, someone with 5-8 years experience recommended it. It should work out if the box right?

Do you get the point now? You have to review the specs to make sure the lens will fit your intended use. In my case, I wanted the lens to fit without modification to the mount. Hence why I was looking at the MBF spec of the lens to make sure I wouldn’t end up in the same situation Tony did, and have to modify the lens mount.

But yet you question why it was important and why I was looking for lenses with 6mm MBF or lower. I showed you why and but you still don’t understand it.

It takes a lot for someone to admit they are wrong… especially one who claims 5-8 years of experience.

PS yes I misspelled the word embarrassed wrong. Was typing too fast.

Now you can admit you were wrong about the rest.

Next time, don’t recommend something that isn’t going to work because people will take your word for it because of your “5-8 years experience”. But in the end, they bought a lens that wouldn’t work. Can they make it work? Yes but with extensive modification that could risk damaging their device.

 

[TonyM]

There are a few 3 MP 8mm starlight lenses available now from Treeye and Yumiki that I don't recall seeing when I purchased the two different 6mm versions I own. There's a 4K 8mm available now too.(10.5 mm BFL)

Yumiki M12 CCTV 3MP 8mm lens F1.5 Focal Length 8mm Sensor 1/2.5"​

Starlight Lens 8mm CCTV Lens HD 3.0Megapixel IP Cameras Lens F1.5 M12​

4K Lens 12Megapixel Fixed M12 Lens 8mm Long Distance View 1/1.7 inch For IMX226 IMX178 4K IP CCTV camera or 4K Action Camera​

@pinoyplaya4life I didn't take the post above from Dashmellow (on Nov 6th) as a direct recommendation. It is just a list of 8mm lenses available from sellers we have used in the past, in response to me saying that I was interested in trying an 8mm lens. He even pointed out the 10.5mm BFL on the 4K lens that I eventually bought. Dashmellow doesn't have an A139, and did not know the lens holder depth until at least Nov 29th when I posted an image of the lens holder.

I did my own research, looked at the specs I could find, took some in-car measurements and made scale drawings taking into account the size & shape of the remote camera housing and the slope angle of my windshield. Thus, I anticipated that the lens would hit the glass and I had some ideas in mind to overcome that. Certainly I could have done more to check whether the 8mm lens would engage with the existing lens holder in the remote camera, but it was only an experiment rather than a long-term plan so I didn't mind if it needed a bit of DIY to make it work.

My long-term plan is to install the 8mm lens into a Mobius 1S that I bought at the same time, and I know that it will fit that camera. I was simply exploring the potential of the A139 remote camera as a base for telephoto lens modifications, and I was careful to describe my installation steps in this thread so that anyone else who might follow would know what to expect.

 

[pinoyplaya4life]

@pinoyplaya4life I didn't take the post above from Dashmellow (on Nov 6th) as a direct recommendation. It is just a list of 8mm lenses available from sellers we have used in the past, in response to me saying that I was interested in trying an 8mm lens. He even pointed out the 10.5mm BFL on the 4K lens that I eventually bought. Dashmellow doesn't have an A139, and did not know the lens holder depth until at least Nov 29th when I posted an image of the lens holder.

I did my own research, looked at the specs I could find, took some in-car measurements and made scale drawings taking into account the size & shape of the remote camera housing and the slope angle of my windshield. Thus, I anticipated that the lens would hit the glass and I had some ideas in mind to overcome that. Certainly I could have done more to check whether the 8mm lens would engage with the existing lens holder in the remote camera, but it was only an experiment rather than a long-term plan so I didn't mind if it needed a bit of DIY to make it work.

My long-term plan is to install the 8mm lens into a Mobius 1S that I bought at the same time, and I know that it will fit that camera. I was simply exploring the potential of the A139 remote camera as a base for telephoto lens modifications, and I was careful to describe my installation steps in this thread so that anyone else who might follow would know what to expect.

regardless… and the fact that he didn’t even have proper measurements of the camera, he shouldn’t be recommending something especially not knowing what the design constraints are. Does he think all lenses will work just because it worked on his mobius (or whatever camera he tried them on)? Even if the cameras are very identical in specs with exception of the length of the mount, it does not guarantee that if one lens works with one, it works on the other.

Its great that @TonyM understands how it works… but I’m still surprised that @Dashmellow cannot grasp the importance of MBF for this application and nor does he understand why.

Between the BFL and MBF, BFL doesn’t matter for fitting a lens properly as long as MBF is less than 6mm to allow for at least minimal engagement. This is what he does not understand.

The first lens on his link could potentially work but the lens might not be fully secured in place

The second lens he linked, Starlight, will work perfectly

The third lens he linked, is the lens you purchased, and may have issues threading to secure in place (which was demonstrated on your attempt to install it).

With all specs aside, the MBF is what you need to find if the lens will have proper thread engagement to your lens mount.

 

[Dashmellow]

@pinoyplaya4life, with all of your self righteous bluster about physics and science and mathematics you seem to be rather clueless in so many ways. If you really believe that "back focal length does not matter" you have a few things to learn about how all this works.

Between the BFL and MBF, BFL doesn’t matter for fitting a lens properly as long as MBF is less than 6mm to allow for at least minimal engagement. This is what he does not understand.

This is incorrect. You need more than "minimal engagement" to focus your lens. BFL is the key metric required for this to work. That is the reason "BFL" is featured in large bold text on the diagram @TonyM posted. Apparently, you are the one who doesn't understand.



Your notion that BFL doesn't matter reveals you to be woefully misinformed.



The other thing you fail to understand is that it is often rather difficult if not impossible to find an aftermarket lens that perfectly matches the all the variables of your particular lens mount and sensor size, thread depth, position of the mount within the camera housing or fit in the housing, etc. You can look all you want but you may well not find an aftermarket lens with the exact perfect specs. Many successful lens conversions involve lenses that are not the perfect mathematical matches you postulate. Usually the best one can do is come close enough to make it work on your particular install. This is the reason that @TonyM had to replace the lens mount and alter the RF shield on his A139 to get this to work. Otherwise the lens a good match to accomplish what he set out to do but certainly not plug and play. I've had similar experiences altering lens mounts or camera housings to get aftermarket lenses to work in certain cameras.

I also can't help but notice you don't even mention matching a lens to sensor size in all your "calculations". You haven't revealed what lens you claimed to have ordered so it will be interesting to see your results, assuming you can install it properly.

PS yes I misspelled the word embarrassed wrong. Was typing too fast.

P.S. How amusing that you find it necessary to insult me over a misplaced decimal point I posted at 2AM yet you hypocritically toss off the fact that you don't know how to spell. You can't have it both ways, bro.

Apparently throwing out gratuitous, self righteous insults seems to be your thing.

 

[pinoyplaya4life]

@pinoyplaya4life, with all of your self righteous bluster about physics and science and mathematics you seem to be rather clueless in so many ways. If you really believe that "back focal length does not matter" you have a few things to learn about how all this works.



This is incorrect. You need more than "minimal engagement" to focus your lens. BFL is the key metric required for this to work. That is the reason "BFL" is featured in large bold text on the diagram @TonyM posted. Apparently, you are the one who doesn't understand.

View attachment 63529

Your notion that BFL doesn't matter reveals you to be woefully misinformed.

View attachment 63530

The other thing you fail to understand is that it is often rather difficult if not impossible to find an aftermarket lens that perfectly matches the all the variables of your particular lens mount and sensor size, thread depth, position of the mount within the camera housing or fit in the housing, etc. You can look all you want but you may well not find an aftermarket lens with the exact perfect specs. Many successful lens conversions involve lenses that are not the perfect mathematical matches you postulate. Usually the best one can do is come close enough to make it work on your particular install. This is the reason that @TonyM had to replace the lens mount and alter the RF shield on his A139 to get this to work. Otherwise the lens a good match to accomplish what he set out to do but certainly not plug and play. I've had similar experiences altering lens mounts or camera housings to get aftermarket lenses to work in certain cameras.

I also can't help but notice you don't even mention matching a lens to sensor size in all your "calculations". You haven't revealed what lens you claimed to have ordered so it will be interesting to see your results, assuming you can install it properly.



P.S. How amusing that you find it necessary to insult me over a misplaced decimal point I posted at 2AM yet you hypocritically toss off the fact that you don't know how to spell. You can't have it both ways, bro.

Apparently throwing out gratuitous, self righteous insults seems to be your thing.

I knew you would go down the rabbit hole of throwing in the other specs. As I mentioned on my other post, with all other specs aside, just between the BFL and MBF, what matters to the proper engagement is the MBF. You are throwing it out of context. In the context of “will the lens mount to the existing lens mount…..do I need to worry about BFL?” the answer is straight up NO; therefore it doesn’t matter in that context.

Of course all other specs of the lens must work all other aspects of the design. That wasn’t the question. The question you asked was why I am looking for lenses with a very specific MBF.

I answered your question. It doesn’t mean all other aspects of the lens doesn’t matter. Do I want a 120mm lens? of course not. Do i pick a lens that has a different mounting system as the current one? of course not. All other aspects of the lens still needs to meet the design constraints.

But as I mentioned, you do you.

You still haven’t answered the question why you advertised that specific 8mm lens knowing it wont work without having difficulties.

Should another person browsing through this forum purchase the same 8mm lens Tony purchased (to be installed on the A139 interior/exterior camera)? I would advise against it, especially if they are new to this since its not a simple plug and play.

 

[Dashmellow]

I knew you would go down the rabid hole of throwing in the other specs. As I mentioned on my other post, with all other specs aside, just between the BFL and MBF, what matters to the proper engagement is the MBF.

Of course all other specs of the lens must work all other aspects of the design. That wasn’t the question. The question you asked was why I am looking for lenses with a very specific MBF.

I answered your question. It doesn’t mean all other aspects of the lens doesn’t matter. Do I want a 120mm lens? of course not. Do i pick a lens that has a different mounting system as the current one? of course not. All other aspects of the lens still needs to meet the design constraints.

But as I mentioned, you do you.

You still haven’t answered the question why you advertised that specific 8mm lens knowing it wont work without having difficulties.

As self righteous and clueless as ever I see. If you don't think all the other factors I mentioned are involved in doing lens conversions or don't think BFL is important you may have a few surprises coming to you when you actually try this in the real world.

I've really had about enough of your disruptive provocations and insults. You obviously have nothing worthwhile to contribute to the forum based on a review of your posts since you showed up here. Get yourself a life or go troll somebody else.

 

[pinoyplaya4life]

good luck to you sir. Hope that 5-8 years of experience is paying off…. I’m sure you’ve had a lot of lessons learned from your experience. A true engineer wouldn’t make those simple mistakes if they just designed and spec’d things out properly.

PS. I would love to see your schematic on where the lens needs to be properly positioned with these specific design constraints (the A139 remote camera and the 8mm lens mentioned here).

Lets see what you come up with….. my thoughts exactly.