This boils down to the size of the SD Card you have chosen to use.
As soon as you have a new dashcam and have driven around for an hour you can review the contents of the card.
By looking at the size of files it creates you can very simply calculate how much footage (in terms of time) the card can store and thus how long before it starts overwriting old files.
For example, I use a 64GB card.
The dashcam is set on loop recording at the highest HD resolution in 3 min chunks.
That results in files of about 300MB being created for each 3 min clip of footage.
So simple math:
64000 MB capacity divided by 300MB chunks = 213 chunks
Each chunk is 3 min of footage so I will get 213 x 3 = 639 mins in total on the card
That’s about 10 and a half hours.
So, if I have an accident, I can rest in the knowledge that it will be a full 10.5 hours of driving before that accident footage starts to get overwritten by the loop recording.
So unless I am planning on driving the length of the country in the same day I have nothing to worry about. I can simple keep driving and then at the end of the day when I get home, make a copy of the important footage.
The smaller your SD Card the less time you will have before loop overwriting begins. I suggest getting a decent sized card like the 64GB or alternatively reducing the resolution of the recording so the camera can record more footage on the card.
Usually no need - if there is a collision then it creates a separate read only copy of the previous 30 seconds and the following 30 secs so it can’t be over written. You can usually set the severity of the collision for example I have to change mine for dirt roads other wise it records every time you go over a rut (at its most sensitive).
If there is no collision then there is often a button on the camera which has the same effect - all the cameras I have owned have had this facility. I find that very useful for recording wildlife that you pass on the road for example or indeed incidents that occur right in front of you. A one minute recording usually records all you need and more.
If you are buying a camera don’t get one without the "save’ facility button it is a valuable asset to have. Be cautious about reducing the resolution because number plates are quite small and the thing is useless if it doesn’t record readable number plates while travelling at normal speed on a less than perfect surface.
That’s interesting Bruce. I did not know that about dedicated car cams.
But I use a Möbius that I use for other things. It is so small that I use it on my flying models as well.
As Realist suggested, I am also going to do a 10 minute test to see how much the card eats. Then I can work out how Long it will record on the card before over writing.
Done it. On the 32 gig card that I have in it, I can get approx 5.5 hours. Before it over writes. Long enough for me.
I just realised that I could have used Realist calculations and half it.
I have a 32G card but don’t think it held 5 1/2 hours. Most probably an hour or more less than that. On checking the footage, the first clip was somewhere well along my journey, so it had started over riding. Each journey time (from and to home) was about 3 hours, and I didn’t use the cam during the week.
