FAQ’s Watec cameras and Watec lenses, simple basics
Here at Wateccamerashop.com we regularly receive questions from our customers about Watec cameras who prefer some small guidance during their selection process. Through the years we’ve noticed that a couple of questions return to us on regular basis. This made us realize that it would be nice to provide some basic knowledge which can help you in your selection process. Because, there are quite a number of options to choose from. Of course we’re still available for questions.
We have quite a number of Watec lenses in our web shop. Check the Watec spec sheets to determine which lens fits your application (focal length, viewing angle) and the camera module on which it will be mount (thread size and CCD size).
The main difference between C-mount and CS-mount lenses is the flange focal distance. The C-mount lens has a flange focal distance of 17,526mm, the CS-mount has a distance of 12,50mm. There is no specific diameter and no specific CCD size or any further type of standardisation. So, check the specs of each selected product to be sure everything will fit.
In order to use a C-mount lens on a CS-mount camera module we sell adapter rings. Be aware that there are various diameters in the market. In other words, take a good look at the diameters of the lens and camera module. A few examples of what we offer; the C-MOUNT adaptor 30CMA-R(link) has a diameter of 30mm and the C-MOUNT adaptor 34CMA-R(link) a diameter of 34mm.
Sometimes you wish to be able to look closer to an object than a specific lens allows. In other words; you want to minimize the object-lens distance or create macro. You can start looking for lenses, but another possible option is using extension tubes . Please, be aware that each combination of camera module, lens and tube thickness will create unique results. Again, check the specs to be sure you get the desired result with the combination of selected components. To clarify the principle a little, see example below, which we arbitrarily measured in our workshop.
Watec components that were used in this experiment:
- Camera module WAT-902B
- Lens variofocal 8,5 - 85 mm iris manual 1/2" c-mount
- C mount adaptor D=30mm (wat 30CMA-R), flange thickness 5mm, necessary to be able to make the module-lens combination
- Lens extention tube set (thickness: 0,5mm, 1mm, 5mm, 10mm and 22mm)
Results step by step:
- Minimal object-lens distance is 1,2m (according to specs)
- With C-mount adapter and a ring thickness of 5mm creates a reduction of circa 0,6m
- With C-mount adapter and a ring thickness of 10mm creates a reduction of circa 0,9m
- With C-mount adapter and a ring thickness of 22mm creates a reduction of circa 1,07m
- The thicknesses of 0,5mm and 1mm can be used for fine tuning your setup.
- Be aware; the bigger the macro, the more light is needed.
Not all lenses have a iris, because normally the camera module determines the amount of light that has to reach the CCD chip or sensor. A manual or auto iris is added to the lens in case it has a large range, which is the case with variofocal lenses. When used to the maximum (fully extended) the amount of light reaching the CCD chip drops dramatically. Especially when extension tubes are added to the setup. Therefore a variable iris is necessary, be it manual or automatically.
Most of the Watec modules have a BNC connector on the back. This type of connector is mostly used for coaxial cables. The BNC connectors on the back of the Watec modules are male. Wateccamerashop offers various adapters to go from BNC to RCA, a connector which is often use on display-monitors and the video-in feed on TV-monitors. There is also cable available to directly from Watec module to your monitor. See Watec Accessories for all options.
Web editor’s note:
We strive to inform our customers the best way possible. Of course, we realize there always will be new and other questions about Watec cameras which could be worth explaining. Therefore we really appreciate when you let us know if this information was helpful or if you think something is worth adding to this page. Give us your feedback about Watec cameras!