Showing posts with label CS Mount Camera. Show all posts
Showing posts with label CS Mount Camera. Show all posts

Thursday, August 9, 2012

CS Vs C Mount Cameras


Modern cameras and lenses are generally CS mount rather than C mount. With CS mount cameras both types of lenses can be used but the C mount lens requires a 5mm ring (VM400) to be fitted between the camera and lens to achieve a focused image. With C mount cameras it is not possible to use CS mount lenses as it is not physically possible to mount the lens close enough to the CCD to achieve a focused image.
C Vs CS Mount Lens
 
The physical difference is the CS mount lens is designed to be mounted ~5mm closer to the image sensor than a C mount lens. (C-mount lenses are designed to be mounted 17.526mm in front of the image sensor vs. 12.5mm for CS-mount.) You can always use a C mount lens on a CS mount camera by using a 5mm spacer ring (many cameras now have C/CS selectable adjustment screws or rings). You can never use a CS mount lens on an older style C mount camera unless you are willing to physically modify the camera. Cost wise the CS mount lens is much less expensive since it uses fewer glass elements. Quality of image is the same. C mounts are becoming less and less popular and are generally only used on the more telephoto focal lengths such as 25, 50 and 75mm, and bigger zooms.
 
Both the C and CS mount are 1 inch wide (25.4mm) with 32 threads per inch (0.03125 inches or 0.79375mm). This dimension comes in handy if you need to insert a spacer to obtain proper focus. Unscrew the lens (or unscrew the camera from the mount in the case of telescope use and count the turns until proper focus is obtained. Multiply the above dimension by the number of turns to obtain the needed spacer or washer. (Washers are sometimes used as spacers if there are enough threads available.) Example: 1.25 turns x 0.79 mm = 0.9875 or ~1 mm. Many cameras (especially newer ones) have set screws to allow small adjustments in the distance between the lens and the image sensor.


Troubleshooting
A lot of the time when someone is using a CS mount security camera they will sometimes get a fuzzy picture and not be able to focus the image properly. If you look at what we have discussed so far you can probably figure out a possible solution to this. The most common mistake people make is that they will mount their CS mount lens onto their security camera while the 5mm ring is still attached. This ring is only useful if you are using a C mount lens. By simply removing this ring they will allow the CS lens to get close enough to the CCD chip to obtain a proper focus.
By taking the time to understand these differences in mounting for C and CS mount cameras and lenses you will help prevent damages to your surveillance equipment and reduce your workload.

Tuesday, November 29, 2011

What is the NTSC and PAL Setting On DVR?

Many DVRs are compatible with both NTSC and PAL standards. NTSC standard is predominately in North America and PAL in Europe. The PAL and NTSC standard actually refer to the method used to transmit color. The PAL standard actually requires 2 NTSC decoders to display video (one for each line alternatively) while the NTSC standard only requires one. The NTSC standard is supposedly less accurate in color display, but more efficient in the use of resources. In general, the DVR can be set to either decode NTSC cameras or PAL cameras, but not a combination of both at the same time. If you order a DVR in a package with the security cameras, then you shouldn’t have to worry about the setting or compatibility. If, on the other hand you purchase your cameras from one country, and the DVR from another, then you definitely should make sure that the DVR is compatible with the cameras. Check the standard of the cameras (NTSC or PAL) and the standard of the DVR. Remember that you cannot mix and match the cameras.

Also, keep in mind that just because you are in the USA does not mean you cannot have a PAL DVR or PAL cameras, or because you are in Europe does not mean you cannot have NTSC cameras or DVR. In actuality, you only need to be sure that the cameras and DVR are both compatible.