Guest Posted December 25, 2007 Share Posted December 25, 2007 Hey, I am not disagreeing with a choice of quality camera! Just need to understand requirements. Dimensions/weight are the concern. What do you think about this one: http://www.scopious.com/spec-sheet/SCC-C4203_specsheet.pdf Link to comment Share on other sites More sharing options...
Scruit Posted December 25, 2007 Author Share Posted December 25, 2007 What is the lens you use with the camera? It looks like the camera comes without lens. Camera run between $150 and 165 without lens. I paid $150, and also added a $50 Fujinon 2.7-13.5 varifocal DC auto iris lens like this: http://www.scdlink.com/Details.cfm?ProdID=3133&category=23&cf=fr I didn't buy from here, just using their product info page becuase it was the first hit on google for the lens part# Link to comment Share on other sites More sharing options...
Guest Posted December 25, 2007 Share Posted December 25, 2007 2.7mm ... how much is it in 35mm terms? I guess a wide angle is important to get capture enough area visible thru the windshield on the video. Link to comment Share on other sites More sharing options...
Scruit Posted December 25, 2007 Author Share Posted December 25, 2007 Hey, I am not disagreeing with a choice of quality camera! Just need to understand requirements. Dimensions/weight are the concern. What do you think about this one: http://www.scopious.com/spec-sheet/SCC-C4203_specsheet.pdf Very nice. Maybe an overkill, even. The OSD will give you a lot of configuration options. You're stuck with the lens, but it's a nice lens. The size is only about 1cm shorter than mine, but the lens adds anothe 4cm to mine making it about 15cm versus the samsung's 10cm. So it's about 2/3 the size. Link to comment Share on other sites More sharing options...
Scruit Posted December 25, 2007 Author Share Posted December 25, 2007 2.7mm ... how much is it in 35mm terms? I guess a wide angle is important to get capture enough area visible thru the windshield on the video. It's a trade-off. A wider angle will let you see what happening off to the sides (ie did the other car REALLY stop at the stopsign on your left?), but it makes the center of the image seem very small, therefore far away. It gives almost a fisheye effect that make it look like stuff happening 20' in front of you is actually happening 40 or 50' away. This has two huge effects - 1) it makes you look like you're travelling faster than you are because an object that looks like it's 50' away arrives at the front of your car in half the time it appears like it should... 2) If someone cuts you off 20' in front of you it looks like they cut you off 50' away, which makes it look like they gave you plenty of room. At the same time a zoomed image would give much more detail, evem license plates, but at the obvious trade-off of width of view. I chose to get a varifocal lens and I adjusted it to the widest angle I could get while still giving a flat undistorted image - objects appear in better perspective (as good as it gets for a 2d image) That was about 3.5 to 4mm You can google 'cctv lens calculator' and find tons of pages where you plug int he CCD size (1/4 or 1/3 usually) and you can get the size of the field of view at a given distance from the zoom mm, or vice versa. I also looked at a lot of police dashcam videos on youtube to see how they did their zoom they all have nice flat images, no wideangle fisheye distortion. Link to comment Share on other sites More sharing options...
Guest Posted December 25, 2007 Share Posted December 25, 2007 What do you think about this? http://www.chasecam.com/bulletcam.htm#cam I wonder how it works at night... if works at all. Link to comment Share on other sites More sharing options...
D_J Posted December 25, 2007 Share Posted December 25, 2007 Nice Scruit! Yeah I hear you on the reasons why you want these cams. Also had 2 people run into me that lied. One time the sheriff actually had the nerve to list me as the "at fault" driver because I allegedly ran into the other car from the side. What about the driver facing cam you have? Is that for security in case someone tries to break-in to steal the car/parts? I've seen that on Court TV...truly amazing how they catch theives with those hidden cameras. 100% proof in court. Link to comment Share on other sites More sharing options...
Scruit Posted December 25, 2007 Author Share Posted December 25, 2007 Nice Scruit! Yeah I hear you on the reasons why you want these cams. Also had 2 people run into me that lied. One time the sheriff actually had the nerve to list me as the "at fault" driver because I allegedly ran into the other car from the side. What about the driver facing cam you have? Is that for security in case someone tries to break-in to steal the car/parts? I've seen that on Court TV...truly amazing how they catch theives with those hidden cameras. 100% proof in court. The driver cam will show someone who breaks into, steals, steals from or abuses the car. I have a video out there on youtube of the Nissan valet driver gunning the car from 5mph to 72mph in about 7 seconds - full throttle all the way. Also, I've had stuff go missing from my car when it was being worked on - this would show that. Heck, one time (pre-camera) I got my oil changed at one of those 10min oil change places. I had a cold and was down to my last 6 lemon-center Halls mentholyptus that were in the cupholder. As I set off again after the oil change and got 1/4 mile down the road my throat started hurting again and I reached down - only one mentholuptus left. 5 missing. 5 employees. Coincidence? It's not like I could go back and complain about it. Also, I've heard of many times where an at-fault driver attempts to mitigate their blame by accusing the victim driver of not paying attention. "If he'd had his eyes on the road he'd have seen me cutting him off" type of thing. Link to comment Share on other sites More sharing options...
schwinn Posted January 7, 2008 Share Posted January 7, 2008 I've been thinking of setting up such a system in my car as well. I've had a few concerns about it though, as follows: The DVR has a 250GB HD, I assume... how would such a device tolerate the extreme temperatures and vibrations in the car? (In New England, we are looking at temps as low as 10-ish, and high as 100 in the car, I imagine.) I question the reliability of a spinning drive. A flash-based device would certainly eliminate the vibration issue. However, even flash cards have a limited write-life. In a typical digital camera we don't use it up fast enough, but with the thermal cycling and the daily use, wouldn't such a card wear out and start failing? Better yet, in either case, how would you know it's working or failing, anyway? In order to delay the write-death of a flash drive, I was considering running a RAM drive, for example, and writing a continuous FIFO buffer of about 5 minutes, for example. Then, when activated (switch, etc) it would dump the buffer to the drive, then start actively recording to it. This way, the drive would not be written to "all the time", saving it's write-life and could even be parked (spinning drive) to save it from damage (particularly in an accident). This is something I can't see happening with a DVR type device (or even the cheap trafficcam device). That's what led me down the Linux computer path instead of a standalone device, as you have. The camera concern is the biggest issue for me, too. I was going to use some simple webcams and a leftover laptop (laptop HDs have better tolerance, but still concern me) for the brains. A freeware program like Linux and Zoneminder would do the work. Still, your setup sounds like a good start, with better quality than I have seen recently... may I ask how much the major hardware costs? What sort of feedback do you get from the system as its running (display in the car? LED indicators?) Sorry for the barrage of questions, but I'm still thinking of my own system, though I like what you've shown here so far... Link to comment Share on other sites More sharing options...
Scruit Posted January 7, 2008 Author Share Posted January 7, 2008 There are dedicated automotive hard drives (Hitachi EnduraStar) that are goot to -30C. The DVR has a cold temp cutoff where it won't try to start the hard drive until the temp gets to 0C. I am having temp problems when the car sits out outside in 10deg weather all day (garaged at night) so I have to choose between waiting for the DVR to warm up, or driving without the cameras. I'm working with the DVR manufacturer to see if I can get an updated firmware that will allow me to set the cold cutoff to -30C.. Dunno if a flash-based device will have the write speed required for multiple channels of full motion video. I'm not concerned about the DVR being damaged in an accident - All I need is the hard drive - I can plug it into a PC via USB and get the video back. If I'm in an accident bad enough to destroy the hard drive them I probably won't be alive to care about it. I can install an LCD screen in the cabin if I want... But right now my LCD screen is in the trunk. I know it's recording because I can hear it beep twice on startup. If I don't hear the beep then I investigate. Link to comment Share on other sites More sharing options...
Scruit Posted January 7, 2008 Author Share Posted January 7, 2008 I mean it's great to have but really I think in all situations a front facing camera would be sufficient to tell the story. We'll see. Today as I was pulling away from a drive-thru window I checked behind me and saw no cars coming. As I accelerated suddenly there was a car there. I saw him in time and stopped and waited for him to pass - no drama today. Now, this is a great example of why you should never accept liability at the scene of an accident, even if you truly believe you are at fault. I simply don't know if the guy was there and in a blind spot, or if he was driving fast enough that he came around the corner after I started moving.... If he was in a blind spot then any collision would be my fault. Most folks would assume that a person pulling away from a drive-thru window and colliding with a passing car would be automatically at fault - BUT, if the other car was driving so fast that he was not in sight as I started my move then the fault would be his for driving too fast, not mine. I am going to go review the video to figure out what really happened. I can use my rear-facing camera to see when he came around the corner relative to when I started to move... EDIT: Confirmed - He was not in sight as I did my shoulder check (top two images) and he came around the cornder very quickly after I set off. (bottom two images) Lucky I did a second shoulder check. http://i103.photobucket.com/albums/m159/Scruit/DriveThru.jpg Link to comment Share on other sites More sharing options...
schwinn Posted January 19, 2008 Share Posted January 19, 2008 Excellent example, and one of the many reasons I want to have front and rear view. Though, in your example with all these camera inputs available, may as well use them all! I still think a spinning drive is an issue, since although you may not get as much damage, the drive will likely crash the head with the impact, causing damage to the platter and that region of the drive. Even a hard enough stop could do this. However, your mention of the Endurastar is spot-on - the specs say it can tolerate a 2ms shock of 250gs, so it's probably pretty well suited to this environment. Also, if the images are stored in MJPEG format, the resulting MPG file may still be readable despite the few bad areas. Still, do you get any feedback that everything is working well, and does the DVR handle these bad-areas (if any should arise) along the way? (Open/rhetorical question, I imagine.) So, back to one of my previous questions - how much did the hardware cost on all this stuff? Just a rough figure, if you don't mind? Lastly, how does the system work in low-light (ie nighttime)? Can you post an example of a night-situation? Link to comment Share on other sites More sharing options...
Scruit Posted January 20, 2008 Author Share Posted January 20, 2008 Excellent example, and one of the many reasons I want to have front and rear view. Though, in your example with all these camera inputs available, may as well use them all! I still think a spinning drive is an issue, since although you may not get as much damage, the drive will likely crash the head with the impact, causing damage to the platter and that region of the drive. Even a hard enough stop could do this. However, your mention of the Endurastar is spot-on - the specs say it can tolerate a 2ms shock of 250gs, so it's probably pretty well suited to this environment. Also, if the images are stored in MJPEG format, the resulting MPG file may still be readable despite the few bad areas. Still, do you get any feedback that everything is working well, and does the DVR handle these bad-areas (if any should arise) along the way? (Open/rhetorical question, I imagine.) So, back to one of my previous questions - how much did the hardware cost on all this stuff? Just a rough figure, if you don't mind? Lastly, how does the system work in low-light (ie nighttime)? Can you post an example of a night-situation? Hard drive: The DVR is mounted using vibration dampers. Still, I supposed a significant impact may damage the hard drive... I'm working on the assumption that any impact hard enough to destry the hard drive will also kill me, and then I won't care who's at fault. People say that laptop hard drives are better - but the platters are made of a glass-like material and if you hit an old HD with a hammer as hard as you can then shake the drive you can hear the pieces chinking around inside. Desktop HDs have metal platters - which have to me more sturdy, right? I don't know how the filesystem on DVR handles bad sectors... But I do know that this DVR is used in commercial applications (ie At least one European country's metro/bus company) so I'm sure they've solved any bad sector issues... The whole system cost: (rough estimates from memory) - DVR $400 - Cameras: Front $200, Driver $75, Rear $75 - GPS Puck: $75 Video Overlay $120 - Power Controller: Home-made approx $50 in parts / PCB etching supplies - Wiring and connectors: $100 - Mounts: All home-made, about $50 in parts. - Installation: ~16 hours The rear/driver cameras don't see well at night unless there is external light. Oncoming cars/streetlights are ok for the driver cam. The rear cam can seet he headlights of cars behind me, but little else. The front camera handles the dark very well... http://i103.photobucket.com/albums/m159/Scruit/Night_Front.jpg Link to comment Share on other sites More sharing options...
schwinn Posted February 10, 2008 Share Posted February 10, 2008 That's a pretty good view on the front cam. Can you see license plate numbers in the dark through that cam? I might have to build a similar system for myself... seems easier than using linux and other such hardware to do it - I mean, at most, I'll save $400 in the DVR, but the work I'd have to put in for it... and the thermal issues... I don't anticipate much fun there. Do you mind detailing the model numbers and such for these items, so I can consider shopping for them myself? Link to comment Share on other sites More sharing options...
Carter Posted February 11, 2008 Share Posted February 11, 2008 Hard drive: The DVR is mounted using vibration dampers. Still, I supposed a significant impact may damage the hard drive... I'm working on the assumption that any impact hard enough to destry the hard drive will also kill me, and then I won't care who's at fault. People say that laptop hard drives are better - but the platters are made of a glass-like material and if you hit an old HD with a hammer as hard as you can then shake the drive you can hear the pieces chinking around inside. Desktop HDs have metal platters - which have to me more sturdy, right? I don't know how the filesystem on DVR handles bad sectors... But I do know that this DVR is used in commercial applications (ie At least one European country's metro/bus company) so I'm sure they've solved any bad sector issues... Try a SSD, they are more expensive but there are no moving parts. Link to comment Share on other sites More sharing options...
wimwam Posted February 11, 2008 Share Posted February 11, 2008 I can confirm that dropping a laptop drive can cause a platter to crack/shatter. The platters are a very thin ceramic as opposed to platters in a 3.5" HD that are made of metal. The SSD is a great idea, though I am still not convinced that they will last a really long time because of the possible write-failure problems that so many thumb drives have (when you use them to run an OS). With the ridiculously high price of an SSD it is probably not worth it. The RAM disk idea is great, dampen your HD as much as possible and consider adding more shock sensors around the car. When a shock is sensed, dump the contents of the RAM disk to an attached thumb drive. If you only do that when the accident happens then you can prolong the life of the thumb drive. Plus thumb drives are fairly cheap. What bitrate is the video you are recording (you may have said this already and I missed it). It doesn't appear that you are capturing at a super high bitrate so you can probably get away with like a 2GB thumb drive to dump video to in case of accident. Of course the other problem is whether or not the OS drive will survive long enough to get the contents to the thumb drive. What a great project, and man I have almost been creamed by idiots in my locals Dunkin donuts so many times. Link to comment Share on other sites More sharing options...
Carter Posted February 11, 2008 Share Posted February 11, 2008 too bad you couldnt do a RAID set up. I cant imagine both HDs failing together on a hard impact. One of them has to be funtionable. But I dont think RAID can apply here. I could be wrong though? Link to comment Share on other sites More sharing options...
Carter Posted February 11, 2008 Share Posted February 11, 2008 Also, I think the WD Raptor HD have the best shock rating Operating Shock (Read) - 65G, 2 ms Non-operating Shock - 250G, 2 ms Link to comment Share on other sites More sharing options...
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