Which kind of parking mode is more useful?

[Sam369]

I know of two kinds of real parking modes that are potentially practical. One is motion detection with pre-buffer, and the other is recording with reduced FPS like 1 or 5 FPS. Are there other ones?

Which one of these has lower power consumption? Which one uses less storage space? Which one is more reliable when it comes to capturing events?

 

[Gibson99]

well, prebuffer gives you full 30fps so you have more frames to work with when trying to identify someone/something, and since it's stored in the camera's RAM, it reduces the write cycles on your SD card. lower FPS would use less storage space, but if it's constantly writing to the card, that will wear out the card much faster. personally i'd go for higher FPS. ever tried to go frame by frame in a video to catch a license plate? not a simple task, so the more frames you have, the better your odds.

power consumption depends on too many factors (chipsets, sensors, whether the camera runs on 5v or 12v, thermal concerns, etc) so there's no way to know if one camera's parking mode is more energy efficient than another's without testing them.

 

[petepete]

gibson 99

Use k-lite codec thingy for 1 frame at a time... As a car passes at 30fpm usually amongst the blurred frames of number plates you can grab a good one...

5 fps is perfect for slow moving carparks but having run my camera at that on the roads. I know its rare it misses a numberplate but would settle for adjustable 5 to 15 fps ..
30 is overkill and looks good but brings little additional useful information... Also
Comes with the disadvantages of twice the storage space and twice the time to view it compared to 15fps.

 

[Street Guardian USA]

Pre-Buffer with Motion Detection set to On works well. Many of our products have 5-seconds of pre-buffer. All you need to do is add a hard wire kit with battery discharge prevention so you can leave the camera powered 24/7 safely. (PANOBDP is popular)

 

[Sam369]

@petepete
1 or 5 FPS is only for parking mode. Normally, it's 1080p 30 FPS. I think they are fixed under both options, and the modes need to be switched manually. There are many Chinese dash cams using this kind of parking mode. These are just my speculations though. I have ordered a Rexing S300+, so I will know the details in several days.

One concern with the motion detection based parking mode is the sensitivity. If it's not sensitive enough, events may be missed. If it's too sensitive, it may record constantly.

 

[jokiin]

all low frame rate seems to do is make it look like stop motion video, I don't see any real benefit in real world use

 

[petepete]

No you don't see any benefit..

So I will explain more clearly..

As an example .. 15 fps capture played back on vlc at 30 fps does not give the stop motion vidio it plays back at double speed .

This is handy because you can view footage quickly when sifting through for any action.

The useable evidential evidence ( number plates and events) will provide exactly the same result in court or in insurance claim.

You also double your recording time over 30fps setting.

Pretty 30fps looks nice..but I m not making a movie just wanting the same evidence in most convenient way ..

1 good frame is conclusive for numberplatrs and as low as 5 fps will show events clearly.

Why collect all the other pointless fps !!!

Wait a minute..that's because no one offers variable frame rate and its obviously viewed as something negative to be cast aside before any thought goes into it and the benefits realised

 

[jokiin]

my experience and yours seems to differ, in a static environment it's ok, any movement increases the chance of blur and makes for less useful footage

 

[Street Guardian USA]

I agree, if there little to no movement in a static environment maybe, but not fast moving cars/objects etc. (especially at night)

It make more sense to buy a bigger memory card rather than reduce FPS on a smaller card.

 

[petepete]

Tomorrow I will record some footage at 5fps with 100mph closing speed or higher..

I drove for over a month on this setting and from what I have seen I know you are actually wrong on this one.

It is also worth mentioning when people play their 30fps. Back and can't get a numberplate... Play it back a frame at a time and often you can find a single frame with all you need..

 

[Street Guardian USA]

It seems to me you would only have a 5 out of 30 chance of getting a good single frame than, instead of 30 to choose from.

 

[jokiin]

Tomorrow I will record some footage at 5fps with 100mph closing speed or higher..

I drove for over a month on this setting and from what I have seen I know you are actually wrong on this one.
.

I don't have it on our cameras so perhaps it's an implementation issue but I tried this on on a Mobius and saw zero benefit, have they got it wrong, not sure, I thought perhaps the lower frame rate might offer different exposure values but it doesn't seem that way in side by side testing against 30fps

It is also worth mentioning when people play their 30fps. Back and can't get a numberplate... Play it back a frame at a time and often you can find a single frame with all you need..

absolutely, you only need that one frame, you only have 5 to choose from though

 

[Gibson99]

It seems to me you would only have a 5 out of 30 chance of getting a good single frame than, instead of 30 to choose from.

That was my point. With two different 1080p30 cameras rolling, I still could not get a clear read on a license plate at approx 140mph closing speed when a truck dropped something that smashed our windshield. At that speed there were only 3 or 4 frames from each camera where the truck was close enough to the camera that the plate or chassis number might be legible but neither camera gave enough info to piece it together and make a claim against the truck driver or the company.

But this thread isn't about high speed readability. It's about parking mode, which most times means under 10mph. So a higher frame rate is not absolutely required, but it's cheap insurance to make it more likely you'll capture the thing you bought a dashcam for in the first place. Memory cards are dirt cheap now so there's no reason for anyone to use anything smaller than 64gb in their camera anymore.

 

[jokiin]

When I tested this it still created the same file sizes so there was no memory savings, I would have thought the exposure time would be increased but I couldn't pick any difference, maybe it's the way it was implemented, not sure

 

[Dashmellow]

Parking mode is often not just about capturing a license plate or someone bumping into your vehicle. It can be about what is going on around and near your car. It can also be about capturing audio, which you certainly won't at 5 fps. I recall there was a fellow who posted here not long ago about his car getting keyed in a parking garage. The video didn't definitively identify the culprit except for gender but when the woman in the video was caught, the audio the camera had captured of the car being keyed became evidence against her.

Another consideration is that a 5 fps capture rate might easily miss the plate number you want to record. Usually, when a vehicle is parked next to me and is backing up to leave, there is often only a brief moment or two when that vehicle's license plate is at the proper angle to be captured just as the car has backed up and is turning to drive away. I'd rather have thirty frames to click through looking for a good plate capture than 5 fps in such a scenario as it would be quite easy for the slow frame rate to miss it.

I run all four cameras in my vehicle full time when away from my vehicle and I'm often amazed (and just as often rather amused) at the crazy things the cameras capture visually and audibly going on near or right next to my vehicle when I'm not around.

 

[petepete]

When I tested this it still created the same file sizes so there was no memory savings, I would have thought the exposure time would be increased but I couldn't pick any difference, maybe it's the way it was implemented, not sure

a 3 minute file size drops from 350 to 112....on 5 fps.

 

[petepete]

I got the footage and the results surprised me as the light is obviously much reduced compared to summer...

here is how an sj 4000 performs facing rear at 30 fps and this frame is typical and chosen for being no diferent from others other than the van is close.
( by that van must have been travelling fast )


http://screencast.com/t/cj86b9qK


here is a gt680w with external lens set at 5fps and this is the only useful frame as the previous frame the van is not in the picture and the frame after it is too far away...


http://screencast.com/t/IQGae4MMj2zV


I have to concede all my previous tests were done in bright summer light and this dull winter light has a real bad effect on image quality rendering the sj4000 "pathetic" !!!


As a result of these winter tests I will keep the gt680w external lens running at 30fps and as you can see it will capture a much clearer image and even numberplates had it been set to 30fps and caught the van slightly before this image was taken.

One thing is for sure .. it highlights how bad an internal mounted camera image really is in low light .. !!!!

whatever you have. an EXTERNAL lens will always beat it ....

 

[jokiin]

a 3 minute file size drops from 350 to 112....on 5 fps.

as tested on the Mobius it still created the same size file, maybe it's the way they implemented it, not sure

 

[jokiin]

whatever you have. an EXTERNAL lens will always beat it ....

we have an external lens product coming actually

 

[petepete]

we have an external lens product coming actually

pray do tell more

and surprised you ve taken that step when everyone here cant grasp just how bad their footage is through tinted reflective windscreens and fears the very thought of external lens for a host of wildly bandied around reasons !!!!