OT reversing cameras.

Hi all,

Sorry about the blatant OT post, but I'm sure a load of TV type people
will know all about video cameras...

I'm upgrading the stereo in my new pride-and-joy Mondeo to one of
those fancy double-din navigation thingies. The car has nasty privacy
glass which makes it a real pain to reverse after dark, so I thought
I'd hack a hole in the back bumper and bodge in a reversing camera.
Gaffer tape will no-doubt play a vital role in the installation.

Anyway, the question is, which camera do I get? The aim is to have the
ability to get a reasonable view by the reversing lights alone, so I
guess low-light performance is going to be the main requirement.

A quick Google suggests that CCD cameras have better low-light
performance that CMOS, though the specs quoted for individual cameras
don't seem to tally with that. "Lux" values seem to range from 0.01 to
1 regardless of the sensor type. A lot of the cameras have IR LEDs, so
you don't get a "lux" value at-all for those. Of course, no range or
beam pattern info is given for the IR illumination.

So, would a CMOS camera do, or do I need a CCD one? Do I even need to
go to one of the more specialist black-and-white low-light cameras?
Are the "lux" values meaningful at-all? Are a few IR LEDs anything
like enough to light up a wide-angle camera's field of view
effectively?

And I thought buying the camera would be the easy bit...

Cheers,

Colin.

--
Threre's a spam-trap on my return address, just in case you hadn't noticed...

In message , Colin Stamp
wrote
Hi all,

Sorry about the blatant OT post, but I'm sure a load of TV type people
will know all about video cameras...

I'm upgrading the stereo in my new pride-and-joy Mondeo to one of
those fancy double-din navigation thingies. The car has nasty privacy
glass which makes it a real pain to reverse after dark, so I thought
I'd hack a hole in the back bumper and bodge in a reversing camera.
Gaffer tape will no-doubt play a vital role in the installation.

Anyway, the question is, which camera do I get? The aim is to have the
ability to get a reasonable view by the reversing lights alone, so I
guess low-light performance is going to be the main requirement.

A quick Google suggests that CCD cameras have better low-light
performance that CMOS, though the specs quoted for individual cameras
don't seem to tally with that. "Lux" values seem to range from 0.01 to
1 regardless of the sensor type. A lot of the cameras have IR LEDs, so
you don't get a "lux" value at-all for those. Of course, no range or
beam pattern info is given for the IR illumination.

So, would a CMOS camera do, or do I need a CCD one? Do I even need to
go to one of the more specialist black-and-white low-light cameras?
Are the "lux" values meaningful at-all? Are a few IR LEDs anything
like enough to light up a wide-angle camera's field of view
effectively?

And I thought buying the camera would be the easy bit...


Your white reversing light will give enough illumination in the dark and
possibly you are worrying too much about the low light performance of
the camera..

Probably more important is the focal length of the lens, and its depth
of focus. You need to be able to judge distances accurately which may
not be possible unless the field of view of the lens/camera combination
is similar to that of you eyes.

Putting the camera in the bumper may also limit your ability to reverse
using the resultant picture alone, assuming that you can keep the lens
clean.

Don't forget that your insurance may be invalid for non-approved
modifications.

--
Alan
news2006 {at} amac {dot} f2s {dot} com

Thanks for the reply.

On Sat, 6 Dec 2008 18:02:16 +0000, Alan
wrote:

Your white reversing light will give enough illumination in the dark and
possibly you are worrying too much about the low light performance of
the camera..

I was hoping that would be the case. The last cheapo colour camera I
bought wouldn't have been up to the job, but that was many years ago.
I guess the sensitivity has improved a lot since then.


Probably more important is the focal length of the lens, and its depth
of focus. You need to be able to judge distances accurately which may
not be possible unless the field of view of the lens/camera combination
is similar to that of you eyes.

I would probably go for about a 120 degree field of view. I'm hoping
most of them will have a reasonable depth of field because of the
small sensor, but I'm not after ultimate quality - just a view of the
wheelie-bin.


Putting the camera in the bumper may also limit your ability to reverse
using the resultant picture alone, assuming that you can keep the lens
clean.

It'd be nice to get it above the back window. I haven't really checked
it out yet, but I doubt I could make a neat job of installing one
there. At the moment I get no view at-all after dark, so it'll be an
improvement over that whatever happens.


Don't forget that your insurance may be invalid for non-approved
modifications.

The last stereo upgrade I did just increased the premium by a few
quid. Hopefully, this'll be a similar story. I can't see them moaning
too much about the camera in particular. Fingers crossed...

Cheers,

Colin.

--
Threre's a spam-trap on my return address, just in case you hadn't noticed...

"Colin Stamp" wrote in message
...
Hi all,

Sorry about the blatant OT post,

We like OT, because on-topic can be boring.

Anyway, reversing cameras. A few unconnected thoughts, based not on
hypothesis but experience.

Don't be tempted by monochrome. Low light yes, but colour is far better for
aiding perception when looking at a small screen. Monochrome is just
confusing. I don't know how colourblind people drive, other than badly (wait
for the letters written in green ink, although how would they know which ink
they are using?). Low light colour bullets are sensitive enough.

If possible mount the camera so the view includes the back of the vehicle.
This makes it very much easier to figure out what you're looking at, how far
away it is, etc.

Don't put the camera on the bumper. You are creating big blind spots at the
rear corners of the vehicle, plus a false sense of security. Crunch.

You either need to have a camera or monitor that mirrors the image, or, in
the view is significantly downwards, mount the camera upside down. Believe
it or not this looks totally natural on the monitor, like an aerial view.

If you use a bullet cam you will be amazed at how long it stays clean (and
doesn't get rained up) if it is recessed an inch and is looking downwards. I
know you have contraints with a car as to which way it looks though.

IR is a bit crap really. Fixed focus bullets always look blurred, and it's
hard not to get hot spots. And of course no colour.

Reversing lights tend to give hotspots and areas of murky darkness. Try it,
then add a couple of 12V LED arrays in the back window or wherever (one time
we actually put them inside the reversing lamp glass!), possibly with
diffusers made by sanding the glass front (if there is one).

http://www.misumi.com.tw/ac.htm seems to be accurate for view angles, but
don't forget many monitors overscan a bit. Be aware that some cams are 1/4"
and some are 1/3" and the difference in view angle is really significant.
Needless to say the very wide angle cams give a picture that's horribly
distorted.

Sorry if some of this is 'grandmother sucking eggs' or irrelevant to your
purpose.

Bill

So the best way to fit one to my Transit would be upside down aboce
the rear doors?

"Colin Stamp" wrote in message
...
Hi all,

Sorry about the blatant OT post, but I'm sure a load of TV type people
will know all about video cameras...

I'm upgrading the stereo in my new pride-and-joy Mondeo to one of
those fancy double-din navigation thingies. The car has nasty privacy
glass which makes it a real pain to reverse after dark, so I thought
I'd hack a hole in the back bumper and bodge in a reversing camera.
Gaffer tape will no-doubt play a vital role in the installation.

Anyway, the question is, which camera do I get? The aim is to have the
ability to get a reasonable view by the reversing lights alone, so I
guess low-light performance is going to be the main requirement.

A quick Google suggests that CCD cameras have better low-light
performance that CMOS, though the specs quoted for individual cameras
don't seem to tally with that. "Lux" values seem to range from 0.01 to
1 regardless of the sensor type. A lot of the cameras have IR LEDs, so
you don't get a "lux" value at-all for those. Of course, no range or
beam pattern info is given for the IR illumination.

So, would a CMOS camera do, or do I need a CCD one? Do I even need to
go to one of the more specialist black-and-white low-light cameras?
Are the "lux" values meaningful at-all? Are a few IR LEDs anything
like enough to light up a wide-angle camera's field of view
effectively?

And I thought buying the camera would be the easy bit...

Cheers,

Colin.

--
Threre's a spam-trap on my return address, just in case you hadn't
noticed...


You will probably have to get out and clean road dirt off the
lens...........almost every time you want to reverse.

"Colin Stamp" wrote in message
...
Hi all,

Sorry about the blatant OT post, but I'm sure a load of TV type people
will know all about video cameras...

Have you driven a car with a rear view camera picture?
My Nissan has the feature as standard I just can't get used to it and do not
look at it, just use my mirrors. It may well be me but you might consider
if an aid to you before going a head particulary as you going to put holes
in your car.

--
Regards,
David

Please reply to News Group

In article ,
Colin Stamp wrote:
I'm upgrading the stereo in my new pride-and-joy Mondeo to one of
those fancy double-din navigation thingies. The car has nasty privacy
glass which makes it a real pain to reverse after dark, so I thought
I'd hack a hole in the back bumper and bodge in a reversing camera.
Gaffer tape will no-doubt play a vital role in the installation.

Plain ol' reversing sensors are much more use.

--
*Work like you don't need the money. Love like you've never been hurt.

Dave Plowman London SW
To e-mail, change noise into sound.

wrote in message
...
So the best way to fit one to my Transit would be upside down aboce
the rear doors?

If you just want a reversing aid yes. I've done four like that. It works out
that with a high top van and the camera on the ladder racks (or otherwise
high on the roof) a 3.6mm lens with a 1/3" sensor gives you about 18" to
each side of the back of the van at ground level. This overlaps with the
mirrors OK. The view to the rear is about 6ft at ground level.

For vans with no rear windows a rearward looking camera is great. This needs
to be a good low light unit, ideally with a 4mm to 9mm varifocal. Recently
I've used a Night Devil from System Q for this and it works great.

BTW System Q are a terrific firm. Amazing showroom where they let you try
anything out. Very helpful; will go through things with you if you aren't
sure. Trade only though.

Bill

Over ten years ago I bought a little black and white camera for my PC.

Low resolution (but adequate for reversing), wide angle and small.

The software automatically adjusted white balance, and I made the surprising
discovery that it would produce a daylight type image of the completely dark
garden opposite. Within a few seconds it would clearly show details that I
could not see after minutes of dark adaptation.



"Colin Stamp" wrote in message
...
Hi all,

Sorry about the blatant OT post, but I'm sure a load of TV type people
will know all about video cameras...

I'm upgrading the stereo in my new pride-and-joy Mondeo to one of
those fancy double-din navigation thingies. The car has nasty privacy
glass which makes it a real pain to reverse after dark, so I thought
I'd hack a hole in the back bumper and bodge in a reversing camera.
Gaffer tape will no-doubt play a vital role in the installation.

Anyway, the question is, which camera do I get? The aim is to have the
ability to get a reasonable view by the reversing lights alone, so I
guess low-light performance is going to be the main requirement.

A quick Google suggests that CCD cameras have better low-light
performance that CMOS, though the specs quoted for individual cameras
don't seem to tally with that. "Lux" values seem to range from 0.01 to
1 regardless of the sensor type. A lot of the cameras have IR LEDs, so
you don't get a "lux" value at-all for those. Of course, no range or
beam pattern info is given for the IR illumination.

So, would a CMOS camera do, or do I need a CCD one? Do I even need to
go to one of the more specialist black-and-white low-light cameras?
Are the "lux" values meaningful at-all? Are a few IR LEDs anything
like enough to light up a wide-angle camera's field of view
effectively?

And I thought buying the camera would be the easy bit...

Cheers,

Colin.

--
Threre's a spam-trap on my return address, just in case you hadn't
noticed...