Mobius Telephoto Dashcam

[SawMaster]

I'm having no problems with the Samsung EVO Plus 64GB cards and as always the Transcend 400X works well in Mobius. The key seems to be that the cards are set up with FAT32 and not EXFAT, which sometimes causes trouble even though it isn't supposed to I too am of the mind that more than 4fps would be better forvthe reasons already given though I won't speculate on what might be too much or what the minimum should be.

Phil

 

[Dashmellow]

I've had not issues with ANY memory cards I've used in any of my numerous Mobius cameras. One of them happens to be a Samsung EVO 64GB.

 

[Dashmellow]

I agree that a telephoto lenses are quite valuable in a second dash cam and use one myself. From my experience over the last six months of experimentation and testing, I consider 16mm to be far too much magnification to be practical. The simple reason is that it will exaggerate every vibration and bump in the road and the extremely narrow FOV presents a good chance for missing something important. I would hate if I discovered after the fact that my video was slightly blurry from camera shake at the critical moment or that what I needed to capture was out of frame. At this point, I'm of the opinion that the 6mm, 8mm and 12mm lenses offer more reliably stable image capture and a more optimal FOV that still provides good license plate capture at a distance.

As far as 4 fps being some sort of "sweet spot" I'm not so sure. The more frames you capture, the more likely you are to capture key details such as plate numbers. I've often noticed that only one or two frames out of thirty will have a clear readable plate number. Personally, I wouldn't trust such mission critical evidence capture to only four frames. Jeez, I would hate to be recording at 4 fps and discover only after the fact that if only I had recorded at 30 fps I would have captured what I really needed.

One of the things I've observed in four years here on DCT is that the vast majority of members here (probably 95 % +) have never been in a situation where they actually needed to use their dash cam footage in an actual law enforcement or insurance matter and as a result many of the statements about what or what not is required of dash cam footage is speculative, theoretical and sometimes imaginary.

What's all this about saving storage space on a memory card that one would even need to shoot 4 fps? With the cost of a decent 64GB (or more) memory card these days, why not capture as much video data as possible instead of comprising yourself?

The reason for the lower data rate is that you can fit more on the card. 4fps is a lot of frames, and I don't think you are much more likely to get more useful information from 30fps that doesn't involve motion. Professional grade surveillance systems are usually set to 5fps or 10fps, the recent 30fps trend in security cameras is mainly to please consumers who like "smooth video" and don't care or know that they're only getting a few days' worth of recording!

I have tried 64GB Sandisk and Samsung cards and neither worked with the Mobius. It would record a video and then crash as soon as it's stopped. So as far as I'm concerned the limit for these cameras is 32GB. Once I get a second normal angle Mobius I'll mount them on the sides and leave them running 24/7 as parking lot cameras. Sitting still, the data rate seems to be about 0.4mbps which yields 140 hours which is about 5 days

Oh yeah, another bonus of the 4fps is it uses less power because the chip has a lot less processing to do[/QUOTE]

A 64 GB memory card will record an entire day's worth of 30 fps footage. This business of needing to use 4 fps seems like a non-issue, a red herring so to speak. It's not about "smooth video", it's about capturing the entirety of the event in detail.

Using less power is also a non-issue and a red herring. The power consumption of a Mobius camera plugged into a motor vehicle's 12V port is beyond negligible.

You can't compare frame rates for fixed position static surveillance cameras with dash cams in a moving vehicle.

@jackalopephoto, at this point, I'm absolutely convinced that you have never been in a situation where you have needed to submit dash cam footage to law enforcement, attorneys or an insurance company.

 

[Deleted member 37895]

The reason for the lower data rate is that you can fit more on the card. 4fps is a lot of frames, and I don't think you are much more likely to get more useful information from 30fps that doesn't involve motion. Professional grade surveillance systems are usually set to 5fps or 10fps, the recent 30fps trend in security cameras is mainly to please consumers who like "smooth video" and don't care or know that they're only getting a few days' worth of recording!

I have tried 64GB Sandisk and Samsung cards and neither worked with the Mobius. It would record a video and then crash as soon as it's stopped. So as far as I'm concerned the limit for these cameras is 32GB. Once I get a second normal angle Mobius I'll mount them on the sides and leave them running 24/7 as parking lot cameras. Sitting still, the data rate seems to be about 0.4mbps which yields 140 hours which is about 5 days

Oh yeah, another bonus of the 4fps is it uses less power because the chip has a lot less processing to do

A 64 GB memory card will record an entire day's worth of 30 fps footage. This business of needing to use 4 fps seems like a non-issue, a red herring so to speak. It's not about "smooth video", it's about capturing the entirety of the event in detail.

Using less power is also a non-issue and a red herring. The power consumption of a Mobius camera plugged into a motor vehicle's 12V port is beyond negligible.

You can't compare frame rates for fixed position static surveillance cameras with dash cams in a moving vehicle.

@jackalopephoto, at this point, I'm absolutely convinced that you have never been in a situation where you have needed to submit dash cam footage to law enforcement, attorneys or an insurance company.[/QUOTE]

I don't get why you are arguing about this. Some people want longer retention time than you. Your "retention time doesn't matter" gets a lot of businesses into trouble when they find out evidence they needed has been overwritten.

I work in law enforcement Dashmellow. I have submitted dashcam footage to insurance companies and to other law enforcement agencies. My professionally informed view is that the biggest risk is NOT HAVING THE FOOTAGE ANYMORE, not "I don't have 30 frames in a second"

I just don't know how to explain this any more clearly. One purpose of my setup is parking lot monitoring and a day is simply not enough. A day is not enough for any security camera system. Car vs fixed is irrelevant, and no professional in the security field would ever install a system that only stores a day's worth of footage

BTW framerate is even more of a factor in bitrate when a dashcam is moving, because there is no efficiency to be gained by not changing pixels. Every pixel showing the outside in every frame is different when you're in a moving car

 

[Dashmellow]

A 64 GB memory card will record an entire day's worth of 30 fps footage. This business of needing to use 4 fps seems like a non-issue, a red herring so to speak. It's not about "smooth video", it's about capturing the entirety of the event in detail.

Using less power is also a non-issue and a red herring. The power consumption of a Mobius camera plugged into a motor vehicle's 12V port is beyond negligible.

You can't compare frame rates for fixed position static surveillance cameras with dash cams in a moving vehicle.

@jackalopephoto, at this point, I'm absolutely convinced that you have never been in a situation where you have needed to submit dash cam footage to law enforcement, attorneys or an insurance company.

I don't get why you are arguing about this. Some people want longer retention time than you. Your "retention time doesn't matter" gets a lot of businesses into trouble when they find out evidence they needed has been overwritten.

I work in law enforcement Dashmellow. I have submitted dashcam footage to insurance companies and to other law enforcement agencies. My professionally informed view is that the biggest risk is NOT HAVING THE FOOTAGE ANYMORE, not "I don't have 30 frames in a second"

I just don't know how to explain this any more clearly. One purpose of my setup is parking lot monitoring and a day is simply not enough. A day is not enough for any security camera system. Car vs fixed is irrelevant.[/QUOTE]

Well, I based my comments on the fact that you posted 16mm lens footage while driving and spoke of capturing license plates out ahead of you. Parking lot capture is a different matter altogether as far a length of time on the memory card and perhaps power consumption as well. Parking mode is "surveillance" whereas dash cam footage from a moving vehicle is "sousveillance".

I do full time parking mode all the time and have 360º coverage all around my vehicle using four cameras (3 Mobi + SG9665GC). Why would you want a telephoto lens for this purpose?

 

[Deleted member 37895]

I don't get why you are arguing about this. Some people want longer retention time than you. Your "retention time doesn't matter" gets a lot of businesses into trouble when they find out evidence they needed has been overwritten.

I work in law enforcement Dashmellow. I have submitted dashcam footage to insurance companies and to other law enforcement agencies. My professionally informed view is that the biggest risk is NOT HAVING THE FOOTAGE ANYMORE, not "I don't have 30 frames in a second"

I just don't know how to explain this any more clearly. One purpose of my setup is parking lot monitoring and a day is simply not enough. A day is not enough for any security camera system. Car vs fixed is irrelevant.

Well, I based my comments on the fact that you posted 16mm lens footage while driving and spoke of capturing license plates out ahead of you. Parking lot capture is a different matter altogether as far a length of time on the memory card and perhaps power consumption as well. Parking mode is "surveillance" whereas dash cam footage from a moving vehicle is "sousveillance".

I do full time parking mode all the time and have 360º coverage all around my vehicle using four cameras (3 Mobi + SG9665GC). Why would you want a telephoto lens for this purpose?[/QUOTE]

I'm not using the 16mm for parking lot surveillance, I'm experimenting with ntersection monitoring and car counting. I'm working on a cheaper alternative to the setups used by police departments for CCTV in very select locations, and I think that focal length and sensor size can allow a lot of flexibility in placement while also saving a huge amount of money-- The typical police CCTV costs about $30k. An off the shelf sensor like the Mobius's, with an Ambarella chip and 4G transmission and storage system would be far cheaper and allow wider deployment. Onboard storage to a hard drive or big SD card would be even cheaper

 

[Dashmellow]

Well, I based my comments on the fact that you posted 16mm lens footage while driving and spoke of capturing license plates out ahead of you. Parking lot capture is a different matter altogether as far a length of time on the memory card and perhaps power consumption as well. Parking mode is "surveillance" whereas dash cam footage from a moving vehicle is "sousveillance".

I do full time parking mode all the time and have 360º coverage all around my vehicle using four cameras (3 Mobi + SG9665GC). Why would you want a telephoto lens for this purpose?

I'm not using the 16mm for parking lot surveillance, I'm experimenting with ntersection monitoring and car counting. I'm working on a cheaper alternative to the setups used by police departments for CCTV in very select locations, and I think that focal length and sensor size can allow a lot of flexibility in placement while also saving a huge amount of money-- The typical police CCTV costs about $30k. An off the shelf sensor like the Mobius's, with an Ambarella chip and 4G transmission and storage system would be far cheaper and allow wider deployment. Onboard storage to a hard drive or big SD card would be even cheaper[/QUOTE]

Interesting. That puts the discussion is a whole different light. Thanks for the clarification.

As far as the 16mm lens is concerned though and our previous debate, this is a telephoto lens thread, so the topic of low frame rates, memory card usage and parking surveillance is kind of a different subject, no?

 

[Deleted member 37895]

I'm not using the 16mm for parking lot surveillance, I'm experimenting with ntersection monitoring and car counting. I'm working on a cheaper alternative to the setups used by police departments for CCTV in very select locations, and I think that focal length and sensor size can allow a lot of flexibility in placement while also saving a huge amount of money-- The typical police CCTV costs about $30k. An off the shelf sensor like the Mobius's, with an Ambarella chip and 4G transmission and storage system would be far cheaper and allow wider deployment. Onboard storage to a hard drive or big SD card would be even cheaper

Interesting. That puts the discussion is a whole different light. Thanks for the clarification.

As far as the 16mm lens is concerned though and our previous debate, this is a telephoto lens thread, so the topic of low frame rates, memory card usage and parking surveillance is kind of a different subject, no?[/QUOTE]

Yes but I'm not the one who brought it up!

 

[Dashmellow]

Interesting. That puts the discussion is a whole different light. Thanks for the clarification.

As far as the 16mm lens is concerned though and our previous debate, this is a telephoto lens thread, so the topic of low frame rates, memory card usage and parking surveillance is kind of a different subject, no?

Yes but I'm not the one who brought it up![/QUOTE]

Well, you are the one who brought up frames rates, memory card usage and the telephoto lens, and not in connection with parking lot surveillance I might add.

You said, "It's because it's 4fps, it looks like you roll through every stop. It is a normal video at a framerate that is ideal for dashcam use. There is zero need to waste storage space on 30fps".

You brought up the 16mm lens but at no time did you mention or clarify that you were now referring to parking lot surveillance.

You said, "The one use is to be able to capture plates and vehicles at a further distance than a wide angle lens would. For that 4fps is the sweet spot IMO".

 

[Harsh]

Mobius - 8mm(1/2.5"), f/1.5 & 12mm(1/2.7"), f/2.0

 

[TonyM]

Mobius - 8mm(1/2.5"), f/1.5 & 12mm(1/2.7"), f/2.0

The 8mm looks like the more versatile telephoto lens. The 12mm seems almost too close and cuts out detail to the side of its narrow field of view.

 

[Harsh]

The 8mm looks like the more versatile telephoto lens. The 12mm seems almost too close and cuts out detail to the side of its narrow field of view.

Vehicles passing by stay longer within the frame and overall looks slightly sharper than the 12mm.

I'm going to let them be side-by-side for a few more days before deciding which to leave mounted.

 

[Dashmellow]

The 8mm looks like the more versatile telephoto lens. The 12mm seems almost too close and cuts out detail to the side of its narrow field of view.

I agree, 12mm is too long a lens here. 6mm or 8mm seem to be optimal choices for this purpose.

 

[Harsh]

I'll be trying the 6mm as a rear cam. With cars coming towards the camera, I think it should suffice.

Why I'm still in two minds about the 8 or 12 is because even though the FOV is narrower on the 12, it still reads a distant number plate better (at least during the day).

 

[Dashmellow]

I'll be trying the 6mm as a rear cam. With cars coming towards the camera, I think it should suffice.

Why I'm still in two minds about the 8 or 12 is because even though the FOV is narrower on the 12, it still reads a distant number plate better (at least during the day).

For most of us, the 12mm wouldn't be a good choice but for the reasons you've explained about why you want a telephoto it may make more sense.

Then again, maybe you need TWO telephoto Mobi with 8mm AND 12mm lenses. Take two, they're small!

 

[Harsh]

For most of us, the 12mm wouldn't be a good choice but for the reasons you've explained about why you want a telephoto it may make more sense.

Then again, maybe you need TWO telephoto Mobi with 8mm AND 12mm lenses. Take two, they're small!

I would have, if the housing and heatsink design was like the M2, could've stuck them to each other and saved on space too. I've though if doing the same to the Mobius but the heat from the heatsink will definitely cause the VHB to fail.

 

[Dashmellow]

I would have, if the housing and heatsink design was like the M2, could've stuck them to each other and saved on space too. I've though if doing the same to the Mobius but the heat from the heatsink will definitely cause the VHB to fail.

Maybe dual lock tape with the second camera upside down with the image flipped?

 

[Harsh]

Maybe dual lock tape with the second camera upside down with the image flipped?

I remember putting them together to see if such a mounting scheme could work, the heatsink of the one suspended was coming in the way. Will see if I can come up with something to mount them using a single helmet mount.

 

[Dashmellow]

I remember putting them together to see if such a mounting scheme could work, the heatsink of the one suspended was coming in the way. Will see if I can come up with something to mount them using a single helmet mount.

When I did the comparison testing between the A lens and A2 lens I mounted two Mobi side by side touching each other on a small wooden board, Maybe you could do something similar with a small cheese plate from SmallRig. Basically, a sort of miniature version of what @TonyM does with the bigger cheese plate he mounts his test cameras on.

http://www.smallrig.com/smallrig-mounting-cheese-plate-1598.html

 

[Harsh]

When I did the comparison testing between the A lens and A2 lens I mounted two Mobi side by side touching each other on a small wooden board, Maybe you could do something similar with a small cheese board from SmallRig. Basically, a sort of miniature version of what @TonyM does with the bigger cheese board he mounts his test cameras on.

http://www.smallrig.com/smallrig-mounting-cheese-plate-1598.html

Dual-lock might just work. I have a couple of spare housings, just put them together and looks like the dual-lock should provide enough clearance for the heat to dissipate. No harm trying, will give it a shot.

If it doesn't work, I'll probably get the cheese-plate.

Thank you!