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Review: Ambarella A7LA50 Dash Cam & Install

apintofmild

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Although my driving is small potatoes compared to your average sales rep or taxi, I do about double the UK annual average. By my reckoning that makes me twice as likely to be involved in (or witness) a motoring incident (or not, for various reasons, but you get my drift).

Given my liking of all things gadget, I decided a dash cam might be interesting to play with. I do wonder if they're a double edged sword though: It may provide crucial evidence to help apportion blame, but what if I'm at fault? In the absence of any other witnesses, could a third party demand the footage to use against me...?

Before settling on the camera I chose (see later) I did a bit of research. Prices range upward from about £10 quid. There is quite a variation in physical size (often determined by screen size), viewing angle and resolution.

Here's my two penneth:
Personally I wanted a discrete install, so small physical size was crucial. I don't want to advertise the camera's presence as I don't want any hassle from anyone fearing their civil liberties are being infringed by being recorded. Nor do I want some comedian nicking it because it's prominently on display. Plus I really don't like things in my eyeline. Stickers, fluffy dice, phone mounts etc -anything other that the tax disc (now a parking permit) is a definite no no.

Looking at what's out there, viewing angles can be as little as 72 degrees. 118, 120, 140 are other common numbers. A few have 160 degrees, mine claims to have 170 degrees. Commercial vehicles have cameras all over the place with every angle covered. I'm just having the one (for now) so the more it can 'see' the better.

Some cameras offer 'infra red illumination'. I haven't seen the results so can't really judge, but I imagine half a dozen LEDs are going to be pretty weak at best. At worst I think they'll reflect back off the inside of the windscreen and obliterate the picture. To that end IR ***ist was off the menu.

As far as I'm concerned any built in screen is basically a viewfinder. I'd take a small body (with small screen) over a physically larger device with bigger screen. If I need to review any of the recordings it'll be by computer after the fact.

Some of the low end cameras record as little as 640 x 480 pixels. There won't be much in the way of detail there. Mine does up to a massive 2560x1080 which I'd argue is a bit excessive. I don't own a screen with that many horizontal pixels on which to view it! That said a large image viewed small will (almost) always look better than a small image viewed large.
RelativeSizes_zps5ribwun4.jpg
 
In the end I went for the GS52D from Banggood.com ( http://tinyurl.com/zd5wqhm ). A few cameras on the market boast they feature an Ambarella chipset. The blurb reads well, but I've not been able to see any impartial evidence that this is any better or worse than any other technology.

Mine has GPS functionality via a separate plug in module. Not sure if GPS is really necessary, but the version with was only slightly more expensive than the version without ( http://tinyurl.com/p75vgsl ) so I went for it.

WhatsInTheBox_zpsmyu8f11u.jpg

The camera comes with suction mount, cigarette lighter power adapter (with about a mile of cable) and the GPS module (about 1.5m of cable). A micro SD card must be purchased separately. I picked up a SandDisk Ultra 32GB card for £8.50. The quality feels half decent. We're not talking Apple or anything, but I'd definitely rate it well above cheap and nasty.

Before 'installing' it I just stuck it to the window and ran some tests. If it didn't perform it wouldn't be staying!

One thing to point out: The internal battery is very short lived. I reckon its sole purpose is to allow the camera to safely close the current file and shut down safely once the ignition is turned off. It lasts literally a minute, maybe two at most, so it's useless for checking recordings (but the tiny screen makes this a bit of a pointless activity anyway). In reality it's not actually an issue, but I'd ***umed that as there's a battery in there it could be used to power the device. You couldn't, for instance, remove the camera from the car and continue recording outside the vehicle (at least not for very long).

Here's a bunch of links. There's a clip for each of the camera's resolutions. All use centre weighted metering and superfine compression. I tried to get daytime footage where I could, but the UK in mid December can be a bit miserable weather wise. It'll be a while before I can gauge how well it performs in blazing sunshine...

Each file was uploaded straight off the SD card. They've not been fiddled with in any way, though YouTube will have re-compressed them of course. For what it's worth, the native video looks cleaner and plays smoother straight off the card than it does via YouTube, but it'll give you some idea of what to expect (you may need to alter YouTube's replay quality setting for best effect).

The clips which have an active speed display have the GPS enabled (it can only display in km/h, not mph), and those with it stuck at zero it is turned off. A menu setting selects what is burnt in (time/date/speed). The camera can record audio, but I've got it turned off. I didn't want a load of sweary clips: cyclists without lights, drivers on the phone and comatose pedestrians will do that :huh:
 
The card consumption of the native recordings are as follows:

2560x1080P(30fps) 146.9MB per min https://youtu.be/NUDDY86W4tg
2304x1296P(30fps) 146.9MB per min https://youtu.be/BF66bdr6LLM
1920x1080P(30fps) 125.9MB per min https://youtu.be/OgfTStRdczE
1920x1080 HDR (30fps) 125.9MB per min https://youtu.be/eCg8wkSN_Hw
1280x720P(60fps) 105.0MB per min https://youtu.be/jBFgP8Wq_D4
1280x720P(30fps) 63.0MB per min https://youtu.be/8WqO0u0h3QY

I'm surprised at how little distortion the pictures have given the viewing angle. There may be some electronic correction at work here. Vertical elements , like street lamps, remain more or less vertical as they move to the edge of frame. Horizontal elements, like the motorway stanchions, suffer more as they reach the edge of frame but it's by no means terrible.
Having played with the camera for a week or so I think my preferred setting is 1920x1080 HDR. It does seem to be able to pull a bit of extra detail out of the blacks and stops the highlights burning out quite as easily. To that end here are a couple more clips at that setting in lower light conditions.

Darkness: https://youtu.be/peLq4ENeAoY
Dusk: https://youtu.be/NUQPVWro-_Q

With these settings my 32GB card will give me around 3 hours of recording before the oldest files start to be overwritten.
Overall I'm pleased with the results. One thing to mention is the camera comes with software to display the GPS data embedded in the video. This is stored on the camera itself and must be downloaded by connecting up via USB. The installer has no English language option, but I managed to fumble through what I presume is Chinese. It turns out, annoyingly, the software can only open .mov files but the camera records .mp4. In other words it is entirely useless! It might be possible to convert .mp4 to .mov without loosing the GPS information, but I've better things to do. If you're in the same boat try Googling 'datakam registrator viewer'. This is a fully featured (yet free) piece of (Windows) software which will show your video along side a moving map of your location with speed and other data.

ScreenGrab_zps8amwfbiv.jpg
 
I had planned to fit the camera behind the rear view mirror, but was thwarted by the halftone pattern printed on the inside of the glass as the sucker mount just falls off!

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I considered fashioning some kind of clamp for the rear view mirror stalk, or possibly attaching via the headlining but settled instead for a piece of 3mm clear polycarbonate sheet cut to the same shape as the halftone patch on the glass. I stuck this in place with several transparent 3M VHB adhesive (search for 'Richbrook gel 3M'). This gave me a smooth surface for the suction mount without looking too unwieldy.

FittedInside_zpsa1gwx5fw.jpg


From where the driver sits it's all nicely hidden by the mirror. Moving the rear view mirror at an angle allows the screen to be seen, and the buttons to be accessed but I fully expect to not touch it day to day unless I think something of value has been captured.

DriversView_zpsgxltwv2a.jpg


From the outside it's reasonably well hidden. At a later date I may add a bit of mat black paint over the silver ring around the lens as it does stand out a bit.

ExternalView_zpsld7q3rkb.jpg
 
I'd hoped to avoid having to use the supplied cigarette lighter adapter. I wanted to keep the socket free, and I didn't really fancy trying to remove the windscreen pillar trims to route the cable (for fear of damaging them or the airbags underneath). I've got HFT built in and a bit of poking around showed there is a switched 12V feed on the mic module.
Carefully prising off the map reading light lenses reveals two silver screws, and opening the sunglasses holder reveals two black screws (no sunroof on mine :( ). Removing these four screws allows easy removal of the ***embly.

Screws_zps5dfoe592.jpg


The mic module connector has a constant 12V, switched 12V and a ground available.

Connector_zpsn1e97i0d.jpg


I used a fused high efficiency DC-DC convertor module hidden in the roof lining to provide the camera power. At 12V this draws about 200mA with the camera recording. This means the camera must draw close to half an amp at 5V -more than I imagined, and which might have some bearing on the extremely short internal battery life. I reasoned (correctly it seems so far) that an extra 0.2A on a circuit fused at 7.5A probably wouldn't break the bank.

The roof lining isn't sealed in any way at the windscreen, so the mini USB camera connector is able to poke out without causing any damage. Similarly the excess cable to the GPS module can be tucked into the roof to keep things tidy.

With this arrangement the camera is running whenever the ignition switch is in position one. When the ignition is turned off the camera continues to run for several seconds (menu setting) then shuts down.
 
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