To get the best from a spotter it helps to compare the glass len diameters of the type of lens you will use. CCTV zoom lenses generally have 11mm diameter rear glass elements. 'C' mount TV lenses that are better for our purposes generally have 16mm diameter rear glass elements.
The bonus with this type of adaptor is massive because the whole of the wider (16mm) C mount rear glass lens sees the whole of the CCD sensor edges through a 16mm hole rather than the cheaper ebay types that screw into the M12 threaded camera neck with a narrow 10.5 mm hole through them that is designed to nearly match up with the small (11mm) rear glass element of the zoom type CCTV lens. The Ebay one therefore obstructs some of the edge detail and light that exits a 'C' mount lens on the way to the camera sensor.
My 'C' mount lens/E700 adaptors also have four substantial M4 threaded fixing holes to aid fixing both the lens and camera to your panel.
They are designed to reliably and robustly fix a C mount lens to a panel or box, then use the 16mm diameter neck of any metal cased camera to accurately centre and glue it into the rear of it using silicone bathroom sealant on the metal case. Note the camera body, being inside a protective box is not subject to the occasional handling knocks that the external lens would get, and the sealant sticks like shit to a blanket.
Notice the O-ring around the neck of the adaptors.
The O-ring allows the adaptor to be tilted by adjusting the tension of the fixing screws so the camera and lens views slightly lower than what a fixed torch is centred at. We/you don't need much light in the foreground and getting the light beam higher in the monitor allows the beam to light up the distance better, partly because the foreground brightness would otherwise be shuttered out by the camera, which would then shutter out the distance too. You can avoid that by aiming the torch high - or the camera and lens low.
Note the different E700 camera lens lengths and the length of the neck they screw into. A 16mm lens neck needs to be cropped back because C mount lens flange focal length has to get closer than the standard neck length would allow. An E700 with a 12mm lens neck doesn't need to be trimmed back because its shorter, allowing the C mount lens barrel to retract close enough to achieve infinity focus.
You will need to fit the adaptor into a 20mm hole in your panel or box. (Some of my remaining adaptors only have two fixing holes), then drill through its 4mm threaded fixing holes used as hole guides with a 3mm drill bit, then remove the adaptor and drill out the 3mm holes in your box to 4 mm - or 5mm to allow a little latitude.
Note that CS mount cameras have a shorter back focal length than C mount cameras despite having the same thread. These adaptors are not designed to be used with CS mount lenses as they will not allow the lens to get 5mm closer to the CCD sensor at the inner end of the neck. Also note they are only designed to mount metal bodied cameras that have a 16mm outer diameter lens neck.
