Things to keep in mind when buying a dash cam

[HeePee]

In a nutshell.

The angle of the lens - Bigger is better? Don't think so! The wider the angle, the more details (pixels) you need to process and store. If you have a 170 degrees lens with 1080P resolution, the image quality will be crap. Or, if you have a 130 degrees lens with 1080P and your colleague has a dash cam (and is bragging about it) with a 170 degrees lens with 1296P, then you still win!
Why do you think your phone makes such wonderful videos on 1080p and your dash cam not?! That's because your phone has only a 60 degrees lens angle. So, 1920x1080 (1080p) pixels for a much smaller picture than your dash cam! Your dash cam has to use the same amount of pixels (1080p) for a much wider / bigger picture. So, best to go for a 130 or max 140 degrees lens angle, it gives you sufficient sight on the road.

Video compression - Make sure you buy a dash cam that encodes in H264. It's the best codec and provides much smaller file sizes.

Bitrate - The higher the better. With the codec H264 (video compression); At this moment (what the market does offer @2017), you should buy a dash cam with a minimum bitrate is 15 mbps (1080p ) or 18 mps (1296p), most ideal would be 20 mbps (1440p). The bitrate does not only determine the quality of the video, it also determines the size of the recorded video file (bitrate times seconds = file size). Keep that in mind when buying a SD card.

Wide / High Dynamic range - Don't buy a dash cam that does not offer WDR or HDR. It makes all the difference. Without it, most detail will be lost in shadows. WDR / HDR makes sure that you will have a great light balance. Go Google about it and see the differences.

Lens, CMOS and CPU. Check what lens is being used, what CMOS and CPU (video processor). Look up the specs of the CMOS (the chip that does receive the light from the lens and transforms it into a electrical signal for each pixel embedded on the chip. So, like a solar panel is working). How many pixels has the it, 2M, 3M or 5M? It tells something about the max resolution you get from it. How big is a pixel? The bigger, the more light it can receive. How well does it transform the light into an electric signal? 1.6V, 3.3V? The more sensitive, the better. And what about the CPU (video processor)? The one that builds the video from the electric signals, provided by the pixels on the CMOS. It it fast (bitrate)? How does it encode (H264)? Go comparing lens, cmos and cpu between different dash cam. Google is your friend. Take notice of the Novatek 96650/96660 or Ambarella A7 video processors and the OmniVision OV4689 CMOS. These are today high end chips. But you might not need this high end chips ($), depending what resolution/quality you want.

For a comparison of the video processors, see:
https://dashcamtalk.com/forum/threads/great-specs-overview-of-most-common-video-processors.29447/

Resolution - Important, of course. But only if all off above does apply. Ask your self on what device you want to playback the videos? What resolution is your TV or PC screen? If it's max 1080p, then would you dash cam need more? However, you might want to catch as much detail as possible in case of an accident. With the right video player, like Quick Time Player 7, you can zoom in to watch the video in the original resolution. By zooming in, you can watch 1296P on a 1080p screen. You just don't see the full video picture. But all you want is that license plate, right?
In my view, the more pixels the better, 1440p would be great. That is, with taking into account a great bitrate and a not so big lens angle (130 or 140).

Micro SD card - Don't try to safe any money on the micro SD card. Check the dash cam specs on what types are allowed. Not all dash cams do, for example, support Ultra. Buy one that can support the bitrate and that can stand heat. Also check how many hours of video you can record (life time). Like 10000 or 12000 hours. A good one is the Sandisk Endurance, special made for dash cams. Transcand has also a High Endurance SD card, special made for dash cams. Both Sandisk and Transcand have these Endurance micro SD cards in 32Gb and 64Gb. Note that (also for both) the max write speed is 20Mb/s.


Last the not least(!!) - Always (and really, really always) add a CPL filter to your lens. The one thing that will (for sure and in any case) screw up your video quality is the reflection of your windscreen. No matter how great your dash cam is, the quality will be crap as the reflection of your dashboard will make license plates (on a distance) unreadable. All other things will be grainy. Especially for the lower part of your video. Yes, this is not because of the dash cam, it's because of the reflection. That is why people complain that their dash cam delivers grainy videos. Well, mostly it isn't! It's reflection that can be solved by buying a $15 CPL filer! Note: When you apply a CPL filter, you might need to increase the EV (Exposure Value) with one click up. Just check it out if that's needed or not.


Like a said, in a nutshell. And just basis my experiences so far. I'm sure others have much more to add.

 

[thancam]

Bitrate - The higher the better.

the higher bitrate your cam has, the more often you have to change your memory card

Don't buy a dash cam that does not offer WDR or HDR

a cam with HDR made moving object become blurry. Better to chose WDR (only ready avaible in dascam with sonny sensor like imx291 (in SG9663DC or A119S)

Always (and really, really always) add a CPL filter to your lens

i dont agree. CPL made nigh footage fuzzy. Even a very expensive CPL of SG still does (a little bit but still). Other make night footage to a nighmare at night.
instead: Try to buy a cover of dashboard. In black - of couse.

 

[SawMaster]

I'll disagree on a few points here. One is that you're better off without a CPL if you don't need it, as it darkens the vids at night with most cams. Upping the exposure settung does not cause more light to reach the lens, so it's not really compensating. I've got minor dash reflections but not enough to be concerned about- they never interfere with any parts I want to see. It's a dashcam, not something you'd use to film a Hollywood movie

And similar on wide-angle lenses- which would you rather have: No image at all because of a narrow FOV or something halfway decent which shows far more of what you need even if it isn't perfect? Given a good lens (which many cam's don't have) and only one cam, you need a reasonably wide angle view. A 90 degree lens won't even see the cars to the sides at a stop sign but it's great for getting more detail of what it does see. You really need one of each to get the best

There are other good SD cards for dashcams but I agree that they must be good cards. Lexar and Samsung have recently made some changes in their cards so what used cto be good may not be anymore. SanDisk has some oddities in it's file system and even the one you mention may not be good for every cam. The Transcend 400X seems to work well in almost every cam and is known for exceptionally long life

Pixel size and count is a two-edged sword: More and smaller is better daytime but can hurt at night when a large pixel captures more light which is what you need then, even if there are fewer of them overall. Like the CPL and narrow lenses, if it's not being seen by a pixel well enough to create an image then you get no image of what you wanted to see Ditto higher resolution- it may hurt you at night even if it helps daytime. For now 1080P seems to be the sweet spot for one setting doing both day and night, but a few cams do as well at night at 1440P.

People get hung up on the idea that more and higher numbers is always better Many times it isn't, sometimes it is. Best to keep in mind what the purpose of a dashcam is: to make a video record of you and the cars around you so that if something bad happens, you can prove that you were not at fault. That doesn't take a lot. And no cam will always capture everything- especially number plates- so if you get more that's good but don't expect it.

One thing not touched on by the OP is what I consider most important of all: reliability. You're better off having a 720P cam with a plastic lens that never fails than a 4K cam with a 7 element high quality glass lens that only does it's job 98% of the time Nothing is perfect but the really reliable cams give you 99.9%+ certainty that you'll have usable video when you need it the most.

Opinions will vary and there's never one perfect answer to everybody's needs. Given the size and price constraints of dashcams I am still amazed that we get as much as we do for so little cost- a good dashcam is one of life's very best bargains

Phil

 

[HeePee]

As a reply to your comment: "The Transcend 400X seems to work well in almost every cam and is known for exceptionally long life";

Check the specs of the Transcend High Endurance. It's made for dash cam usage.
https://www.transcend-info.com/Products/No-727

It will last for 12000 hours of video recording.

 

[jokiin]

Insertion and removal is the physical latch, nothing to do with how many hours of operation

 

[HeePee]

Insertion and removal is the physical latch, nothing to do with how many hours of operation

You're right. I removed that part from my reply. Probably when you were replying Both cards have the same max insertion/removal cycle. Thanks.

 

[Dashmellow]

I run four cameras simultaneously and have been using a variety of "standard" memory cards in them. Some of these cards have been in hard daily service literally for years now with no issues after many thousands of hours. The only card that has ever failed on me is a SanDisk Ultra 32GB (one out of three that I own). Others like the Transcend, Kingston, Samsung EVO, all "standard" cards have been absolutely reliable despite heavy long term usage in multiple cameras. Some of these cards were purchased as long as seven years ago.

This whole "High Endurance" thing is more hype than anything else in the sense that you really don't need it. It is not money well spent.

 

[jokiin]

This whole "High Endurance" thing is more hype than anything else in the sense that you really don't need it. It is not money well spent.

yes and no, part of the problem recently is that so many of the once reliable makes and models are using lower cost solutions to try and remain competitive, quality has taken a bit of hit in the models that fill up the majority of sales in the market, I would think for the most part this wouldn't be an issue for most people as this is predominantly the mobile phone market where it's more about storage than absolute performance so would go pretty well unnoticed, for dashcam use where the workload is not as forgiving it may mean skipping the entry level offerings from a lot of brands that were previously quite reliable for our purposes and looking at the faster or higher spec cards instead

 

[Dashmellow]

yes and no, part of the problem recently is that so many of the once reliable makes and models are using lower cost solutions to try and remain competitive, quality has taken a bit of hit in the models that fill up the majority of sales in the market, I would think for the most part this wouldn't be an issue for most people as this is predominantly the mobile phone market where it's more about storage than absolute performance so would go pretty well unnoticed, for dashcam use where the workload is not as forgiving it may mean skipping the entry level offerings from a lot of brands that were previously quite reliable for our purposes and looking at the faster or higher spec cards instead

I see your point but so far have not run into any issues, even with more recent card purchases that have been in heavy use. I think of memory cards as a kind of disposable media that can be recorded over just so many times like VHS tapes but so far have just not had a card die of old age. Maybe I'll see that happen one of these days with an older card or a newer one with "lower cost solutions". Curiously, I've also put my old SanDisk Ultra cards back into service beginning about a year ago in Mobius beta testing just to see what would happen and the two of them are doing just fine after hundreds of hours beyond what they already had on them. Go figure.

BTW, speaking of standard cards, two days ago I stumbled on an amazing clearance deal at the local Walmart that I just couldn't pass up. It was a Samsung EVO 128 GB for 25 bucks! Considering the current market for memory cards it was a great find.

 

[HeePee]

They released some more info on the new VIOFO WR1. But still no mention of the video processor or other detailed specs.

http://www.viofo.com/car-dash-cam/51-viofo-wr1-car-dash-camera.html

 

[jokiin]

BTW, speaking of standard cards, two days ago I stumbled on an amazing clearance deal at the local Walmart that I just couldn't pass up. It was a Samsung EVO 128 GB for 25 bucks! Considering the current market for memory cards it was a great find.

some brands in particular seem guilty of substituting lower grade components and are proving to be flaky, Lexar were a card I would have no hesitation recommending previously but their recent stuff has really taken a dive, PNY were very solid before also but recent feedback suggests something has changed

BTW, speaking of standard cards, two days ago I stumbled on an amazing clearance deal at the local Walmart that I just couldn't pass up. It was a Samsung EVO 128 GB for 25 bucks! Considering the current market for memory cards it was a great find.

in the current market that's very hot pricing and certainly worth trying out, our current buy price ex factory on High Endurance or similar U3 MLC based cards is more than $1 per gigabyte, pricing is really out of hand right now

 

[Dashmellow]

some brands in particular seem guilty of substituting lower grade components and are proving to be flaky, Lexar were a card I would have no hesitation recommending previously but their recent stuff has really taken a dive, PNY were very solid before also but recent feedback suggests something has changed

Maybe that's an explanation? I've not used those brands. I've mostly stuck with Transcend, Kingston and Samsung over the years (and those very old SanDisks). Everything just works.

in the current market that's very hot pricing and certainly worth trying out, our current buy price ex factory on High Endurance or similar U3 MLC based cards is more than $1 per gigabyte, pricing is really out of hand right now

The 64GB Samsung EVO cards I have have been rock solid performers for about a year now so I jumped on the 128GB version at that price. On Amazon right now you can buy one for about twice what I paid.

 

[Moon]

When viewing lots of videos on YouTube .. I've noticed a number are quite heavily pixellated (varying) which is most noticeable just above the front edge of the bonnet on the road surface. What is causing this? I'm thinking it is the SD card struggling to write data quickly enough. Is this correct .. or is it due to something else?

I've purchased a Transcend 64GB U3 for my MF3 which does 1440p. I chose this because I didn't want the SD card struggling, and some folks recommend the U3 for 2/2.5, 4K recordings.
I don't get any pixellation in my Videos, although I do get a bit of jittering occasionally .. and often get a short frame freeze for a second.
I have a 2008 MAC and play the Videos on 'Quick Time 10.4' .. which is not what came in the Computer QT-7 iirc?) but still must be pretty old .. so no idea whether that may be causing or contributing to the glitch using the latest 1440p recording.

Do you get pixellation in your videos .. and what Brand type and speed is your SD card?

Thoughts?

 

[jokiin]

I've seen recent reports of Samsung issues but for those I strongly suspect it's an issue with the cards not actually being the genuine article, they do unfortunately get copied a lot

 

[Dashmellow]

When viewing lots of videos on YouTube .. I've noticed many, if not most .. a lot of the footage is quite heavily pixellated, which is most noticeable just above the front edge of the bonnet on the road surface. What is causing this? I'm thinking it is the SD card struggling to write data quickly enough. Is this correct .. or is it due to something else?

I've purchased a Transcend 64GB U3 for my MF3 which does 1440p. I chose this because I didn't want the SD card struggling, and some folks recommend the U3 for 2/2.5, 4K recordings.
I don't get any pixellation in my Videos, although I do get a bit of jittering occasionally .. and often get a short frame freeze for a second.
I have a 2008 MAC and play the Videos on 'Quick Time 10.4 .. which is not what came in the Computer QT-7 iirc?) but still must be pretty old .. so no idea whether that may be causing a bit of a glitch withe the latest 1440p recording.

Do you get pixellation in your videos .. and what Brand type and speed is your SD card?

Thoughts?

QuickTime Player should run your videos just fine. If your older computer is shy on RAM you could get some stuttering or jittering though. Try quitting as many other applications as possible when viewing video as that should help.

 

[HeePee]

QuickTime Player should run your videos just fine.

I don't think that Quicktime Player (standard) does allow you to play the video in the original resolution. It will always plays the video to fit the PC monitor size. With a 1080p PC screen, it means it will scale down a 1296P video to 1080p. This makes the number plates much harder to read. The scale down will go with the cost of the detail. If you have a 1297p (or 1440p) dash cam, you want to play it in that resolution. With Quick Time Player 7, it does provide me the option to play the video in it's true resolution, providing all the details. Of course it will only show part of the screen as 1296p does not fit a 1080p monitor. This type of 'zooming in', gives great detail on the number plate. Playing a 1296p/1440p video (full screen) on a 1080p monitor will make a number plate hard to read (and screw up any other type of detail).

 

[Moon]

Cheers fellas (as always)

Computer came with 2Gig Ram .. but upped to max - 4GB
Drooling over upgrading to a 4K Retina .. only still having a 2002 Crt TV .. the priotity is tilting towards holding off for a new decent sized OLED TV...... Oh Yeah .. baby! Hey .. I'm sure my 1440p Video will look fine on that .. yeah?
------------------------------------------------------------------------------------------------------------------------------

HeePee .. Welcome aboard .. I take it .. you use a MAC? (Just got lucky?)

I had the option of using QT 10.4 or QT 7
I opted for the latest .. which worked .. but after seeing the jitter and freezing, I tried the 7.
The PQ was good .. only the frames you see are like it Kangaroo jumped .. so it missed a whole chunk of frames each time. I read somewhere else by a MAC user .. that the QT 7 doesn't work .. only it does for you?

Resolution on this 2008 iMAC - 1680x1050

Gotta say ... I'm loving all this Dash Cam stuff.

 

[HeePee]

@Moon; I've a Macbook Pro (2009), running Quicktime Player 7. I've upgraded RAM to 8Gb and installed a SSD. Dash cam video's (1080p and 1296p) are running smoothly with Quicktime Player 7. No kangaroo jumps or missed frames. I only get that if I have a lot of other apps open and running. Best to restart your mac before watching your video's.

 

[Moon]

^ Cheers for the Heads up.

I think we are the only MAC owners around here .. so it's good to have at least one of us that knows a bit about what's going on.
Another bonus is that you have one from the same era .. Just what the Doctor ordered. Hope you plan on sticking around for a while?

 

[jokiin]

@Dashmellow is a regular here and an experienced Mac owner