Camera/screen based rear-view mirrors - dangerous?
Discussion
Some of the new models that are being released with camera based door mirrors and rear-view mirrors, I think these are dangerous and have no real advantage apart from a small aero benefit.
When you use a normal mirror, your focus point is at ~infinity i.e. the same as the view through the windscreen, but a camera screen mirror is on the dashboard, so your eyes have to re-focus at 0.5-0.75m. This means you cannot just glance at the mirror, it can take a second to refocus, especially for the elderly. If you wear glasses for driving, this is even more difficult. So, a maneuver like changing lanes, which can require several mirror checks, is going to takes longer, with the drivers eyes away from the forward direction.
Also it is more to go wrong, and would be an expensive fix for something that is required in an MOT.
Why make things more complicated when they work fine as they are.
<rant over>
When you use a normal mirror, your focus point is at ~infinity i.e. the same as the view through the windscreen, but a camera screen mirror is on the dashboard, so your eyes have to re-focus at 0.5-0.75m. This means you cannot just glance at the mirror, it can take a second to refocus, especially for the elderly. If you wear glasses for driving, this is even more difficult. So, a maneuver like changing lanes, which can require several mirror checks, is going to takes longer, with the drivers eyes away from the forward direction.
Also it is more to go wrong, and would be an expensive fix for something that is required in an MOT.
Why make things more complicated when they work fine as they are.
<rant over>
This has been discussed at length before.
I’m firmly in the camp that mirrors are better.
They are not compromised by a small amount of dirt or water.
And you are required to focus on the real object in the mirror, not just at a fixed screen.
This requirement to focus on the actual object informs us about the distance and dynamics of the object imho.
I’m firmly in the camp that mirrors are better.
They are not compromised by a small amount of dirt or water.
And you are required to focus on the real object in the mirror, not just at a fixed screen.
This requirement to focus on the actual object informs us about the distance and dynamics of the object imho.
I am no luddite but it does seem to be a combination of someone doing the maths across a huge fleet and coming up with a saving that would be impressive for a single vehicle, and technology for technology's sake.
If we had such a thing as a holographic camera and display, then (I think... Optics has never been my strong suit!) the included wave information would allow for focus to shift and preserve that benefit of mirrors. But we don't have that, so we're losing information through the limitations of the technology we do have.
If we had such a thing as a holographic camera and display, then (I think... Optics has never been my strong suit!) the included wave information would allow for focus to shift and preserve that benefit of mirrors. But we don't have that, so we're losing information through the limitations of the technology we do have.
swisstoni said:
This has been discussed at length before.
I’m firmly in the camp that mirrors are better.
They are not compromised by a small amount of dirt or water.
And you are required to focus on the real object in the mirror, not just at a fixed screen.
This requirement to focus on the actual object informs us about the distance and dynamics of the object imho.
It would be possible to make the display appear at infinity, similar to a hud. You would still lose the change of focus for much closer objects and moving your head for perspective, however it would help with focal accommodation. Of course if you had head tracking and steerable cameras you could have perspective, with eye tracking and a display that matched the focal distance with the camera focus you could have change in focus for close objects too. Getting those to work well would be rather more difficult though. I’m firmly in the camp that mirrors are better.
They are not compromised by a small amount of dirt or water.
And you are required to focus on the real object in the mirror, not just at a fixed screen.
This requirement to focus on the actual object informs us about the distance and dynamics of the object imho.
Our Leaf has the screen mirror. You can switch it off (works as normal mirror). If you couldn't, I wouldn't like it. Side mirrors would be a pain as normally you need them urgently!
The point about refocusing is valid - although I've got used to it now
I wonder if as you get older it gets harder to refocus ? Could make things harder for older drivers as more cars adopt this tech.
The point about refocusing is valid - although I've got used to it now
I wonder if as you get older it gets harder to refocus ? Could make things harder for older drivers as more cars adopt this tech.
I have not tried one of these. But I imagine extensive testing has been done, so the focussing thing is as best it can be. There may be eye-training needed, in that, the driver is re-focussing from the distance to a near object in the cabin, but in fact the image is set at a distance, so maybe there is some re-re-focussing taking place. Difficulty in focussing with age is likely a slow hardening of the lens, but I am not an ophthalmologist.
I prefer standard door mirrors. They give an extra width protection to the body sides, hence I don’t have folding mirrors. Also, as said, you are halfway towards a side glance or rear shoulder glance too. Additionally, when passing a car with door mirrors, you can see if the driver is observing you.
I prefer standard door mirrors. They give an extra width protection to the body sides, hence I don’t have folding mirrors. Also, as said, you are halfway towards a side glance or rear shoulder glance too. Additionally, when passing a car with door mirrors, you can see if the driver is observing you.
AndySheff said:
A mate of mine drives a HGV.
He hates them, and has also had one stop working whilst out driving.
I don't think I'd like them on a car of mine.
Can't comment on the car ones, but the lorry ones are excellent. Mercedes started it. He hates them, and has also had one stop working whilst out driving.
I don't think I'd like them on a car of mine.
The lack of a mirror removes a blind spot, the mirrors also have additional warning systems for vehicles in certain proximity and can be set up for different trailer lengths. If for some reason they donstop working then you have a temporary stick on mirror. I think the advantages far outweigh the disadvantages.
Must be trained on how to use them properly though...
essayer said:
Our Leaf has the screen mirror. You can switch it off (works as normal mirror). If you couldn't, I wouldn't like it. Side mirrors would be a pain as normally you need them urgently!
The point about refocusing is valid - although I've got used to it now
I wonder if as you get older it gets harder to refocus ? Could make things harder for older drivers as more cars adopt this tech.
Yes. Along with most aspects of vision so could be a problem for older drivers.The point about refocusing is valid - although I've got used to it now
I wonder if as you get older it gets harder to refocus ? Could make things harder for older drivers as more cars adopt this tech.
As an aside, threads like this will always attract the "my eyes are perfect" comments, but I've never met a pilot over 40 who doesn't wear corrective lenses... Which leads me to believe a lot of people have eyesight good enough to drive, but not perfect, and not tested either.
Indeed, I hadn't had an eye test for a couple of years and didn't even realise I needed glasses until I decided an eye test would be a wise precaution before starting to fly in my early-30s. Turned out I had mild astigmatism. I can get about fine without my glasses, but now I know my vision isn't as good as I thought.
Road2Ruin said:
AndySheff said:
A mate of mine drives a HGV.
He hates them, and has also had one stop working whilst out driving.
I don't think I'd like them on a car of mine.
Can't comment on the car ones, but the lorry ones are excellent. Mercedes started it. He hates them, and has also had one stop working whilst out driving.
I don't think I'd like them on a car of mine.
The lack of a mirror removes a blind spot, the mirrors also have additional warning systems for vehicles in certain proximity and can be set up for different trailer lengths. If for some reason they donstop working then you have a temporary stick on mirror. I think the advantages far outweigh the disadvantages.
Must be trained on how to use them properly though...
It would be interesting to look at this from the environmental point of view too. Traditional mirrors win hands down in terms of the way they work, requiring no power at all to function and having an almost indefinite lifespan. Cameras, conversely, require electrical power to run themselves and any monitors they are connected to. The environmental cost of manufacture is also much higher. There is an aerodynamic benefit to having cameras as they create less drag, but does that really balance out over the life of the vehicle? Having a two or three camera and multiple screen live television broadcast going on at all times the car is running must be expensive, in electrical terms. Plus all of that stuff can break.
There are also secondary benefits to mirrors always being there, such as the possibility of checking behind when opening the doors of a car which has had its ignition switched off. Are drivers really going to be expected to switch the ignition back on before opening the door?
There are also secondary benefits to mirrors always being there, such as the possibility of checking behind when opening the doors of a car which has had its ignition switched off. Are drivers really going to be expected to switch the ignition back on before opening the door?
Missy Charm said:
It would be interesting to look at this from the environmental point of view too. Traditional mirrors win hands down in terms of the way they work, requiring no power at all to function and having an almost indefinite lifespan. Cameras, conversely, require electrical power to run themselves and any monitors they are connected to. The environmental cost of manufacture is also much higher. There is an aerodynamic benefit to having cameras as they create less drag, but does that really balance out over the life of the vehicle? Having a two or three camera and multiple screen live television broadcast going on at all times the car is running must be expensive, in electrical terms. Plus all of that stuff can break.
There are also secondary benefits to mirrors always being there, such as the possibility of checking behind when opening the doors of a car which has had its ignition switched off. Are drivers really going to be expected to switch the ignition back on before opening the door?
Many traditional mirrors are electric, and also have automatic de-icing elements, but of course can function without a constant electrical supply.There are also secondary benefits to mirrors always being there, such as the possibility of checking behind when opening the doors of a car which has had its ignition switched off. Are drivers really going to be expected to switch the ignition back on before opening the door?
Imagine in x years time when a perfectly good car is worthless because the broken 'camera mirror' is £2k and will take 6 months arrive.
It's bad enough now with 'simple' xenon headlights costing over £1k to replace...hate to think what some of the more modern, all-singing, all-dancing AI LED headlights would cost.
It's bad enough now with 'simple' xenon headlights costing over £1k to replace...hate to think what some of the more modern, all-singing, all-dancing AI LED headlights would cost.
Missy Charm said:
It would be interesting to look at this from the environmental point of view too. Traditional mirrors win hands down...
Don't underestimate the amount of drag that conventional wing mirrors produce. They generate a huge amount of turbulence. Over the total lifetime of a car, you're going to burn hundreds of litres of extra fuel to overcome the extra drag created by the mirrors. How that compares to their environmental cost of manufacture I don't know. mmm-five said:
Imagine in x years time when a perfectly good car is worthless because the broken 'camera mirror' is £2k and will take 6 months arrive.
It's bad enough now with 'simple' xenon headlights costing over £1k to replace...hate to think what some of the more modern, all-singing, all-dancing AI LED headlights would cost.
You aren't going to buy a brand new unit for a cheap second hand car though? By the time a car with them fitted is < £5k used you'll be able to pick them up for a couple of hundred quid. There's already camera mirrors for the Audi etron for sale on ebay for < £750 a pair, and that' a £40k+ car still.It's bad enough now with 'simple' xenon headlights costing over £1k to replace...hate to think what some of the more modern, all-singing, all-dancing AI LED headlights would cost.
https://www.ebay.co.uk/itm/265518116666?hash=item3...
vikingaero said:
They are fine for HGVs that return to RDCs. Plenty of grumblings from drivers who have to park up overnight with loads. With mirrors they have instant view of the security of loads. With cameras, they are simply not on unless the door is opened or the ignition switched on.
Yeah, on HGVs they probably work and as a neighbour of mine got head injuries when an HGV passed him on a narrow road, anything that gets that huge mirror jutting out from the side of the cab is a benefit.Forums | General Gassing | Top of Page | What's New | My Stuff