"Safety Camera Detectors"? "Camera Detectors" which keep you "Safe"?
This is what I think of them. (copied from a post I made on PePiPoo)
To detect Truvelo, Peek, RedSpeed and SPECS (all fixed devices which do not emmit any RF/laser light) you need a GPS style detector. There is no other way to detect them.
To detect fixed Gatso installations and M25 style gantry cameras you can use either a GPS detector or a radar detector.
To detect mobile laser guns you need a laser detector or GPS detector with a list of mobile sites.
To detect portable gatso devices you need a radar detector or a GPS list which includes mobile sites.
To detect a hand-held radar gun... do they still use these? Same as portable gatso.
GPS based systems have a GPS receiver which tracks your position, given a clear enough view of the sky. The unit also has a database built in with the locations of known fixed (and sometimes mobile) camera sites. It can tell from your location and direction of travel if you are heading towards one of these sites.
Problems with GPS devices: The database has to be kept up to date. This usually involves removing the device from your vehicle and plugging it into your telephone line or computer (USB). Of course "computer" does not include anything I have at home, namely a few Linux machines and Macs. I have not seen any ethernet or wireless LAN based ones yet, otherwise I may have one. Needs clear view of sky while operating. Database is only as good as the data entered in it.
Problems with laser detectors: Laser light has a habbit of *not* scattering all over the place (unlike radar which bounces all around quite hapily) so these detectors are possibly not as useful as you might think; once it goes off you've probably been hit.
Problems with radar detectors: They detect the presence of radio signals at somewhere around 24.1 GHz ± 25MHz. That's about it. Traffic light and shop door sensors also use this frequency. Plenty of false alerts.
Problems with GPS databases of mobile sites: The sites are not always occupied. Again with the false alerts.