Aligning a lti speed camera on a lamp post
February 17th, 2010 | by admin |
Note how the video cross hairs are not center of the screen. the officer hears a tone as he passes the laser beam past the lamppost to check the screen cross hairs are correct. If required he then adjusts the laser beam and rechecks his callibration. this should be at the start end end of every speed enforcement video
Duration : 0:0:31
8 Responses to “Aligning a lti speed camera on a lamp post”
By LauraBidin on Feb 17, 2010 | Reply
What is to stop a …
What is to stop a fixed focal length lens being changed to one of a different length halfway through an enforcement session?
By LauraBidin on Feb 17, 2010 | Reply
The date is on the …
The date is on the video? Where is the video?
Zoom lenses are standard issue with LTI’s. The crosshairs are/should not be used to sight vehicles – this is done with the laser’s ‘red dot’ sight – the position of the crosshairs having no impact whatsoever on the laser’s positioning in relation to the vehicle. The crosshairs are after all, aligned by eye, so are only ever a guide as to where the laser was sighted.
By scamola on Feb 17, 2010 | Reply
The date is on the …
The date is on the video. I am happy to be wrong, I cannot yet accept that zoom lenses should be used on this equiptment as the parallex changes on a zoom and id fixed on a fixed lens.
By LauraBidin on Feb 17, 2010 | Reply
You are …
You are highlighting irregular operating practices, not what enforcement officers are trained to do. How old is your video?Parallax error will be evident whatever focal length is used.
However, your understanding of the laser/crosshair relationship is simply wrong.
The laser doesn’t move, the officer cannot alter where it points, BUT, you can move the crosshairs wherever you like, then realign what the video records via the crosshair adjustment to match where the laser is pointing.
By scamola on Feb 17, 2010 | Reply
I have video from …
I have video from an enforcement session where the focal length does move without reallignment. Items that measured 1.0 on the screen measured 1.3 after zooming.
I cant explain why the cross hairs are set so low on this session other than to match the location of the laser. This was only realy posted up to get the opinion of another expert.
By LauraBidin on Feb 17, 2010 | Reply
I am uncertain as …
I am uncertain as to the source of your ‘expert’ knowledge but the position of the laser beam doesn’t move, so it cannot be ‘that low’.
You use the LTI’s sight for targeting NOT the crosshairs.
Once you select a focal length on a zoom, you reconfirm crosshair alignment. You do not alter focal length during use without then realigning.
Crosshairs can be positioned where the enforcement officer wants them, there is NO requirement to have them anywhere specific, that is why they are movable.
By scamola on Feb 17, 2010 | Reply
It is very unusual …
It is very unusual for the cross hairs to be that low. They wouldnt have shipped an LTI with the laser beam that low? Is the laser another loose nuts and bolts case? Some forces have been wrongly fitting zoom lenses. Zoom lenses will target the wrong point once the zoom is changed unless the laser and cross hairs are in the exact center of the lens. This could cause the opperator to generate the slip effect, The court would be under the perception the laser was on the number plate.
By LauraBidin on Feb 17, 2010 | Reply
Why is it pointed …
Why is it pointed out that the crosshairs aren’t central – the operator can position them wherever they like?
Also, there is no way to ‘adjust the laser beam’, if not correct as you say, the crosshairs are adjusted not the laser beam – you have no way of altering the laser without invalidating the calibration certificate.