The Signal Source is Crucial
by Uwe Hoeppner

Despite all the Digitalisation: A Good Video Signal comes from a good Camera with a Matching Lens

Overview of Topics
CCD Sensors
DPS™ Technology
Day/Night Cameras
Day/Night Lenses
Infrared Lighting
System Colour Camera

Today the market offers a wide selection of different products. But nevertheless it is very important to choose the right camera lens combination for the desired application. Therefore it is important and necessary to know more than the leaflet tells you. In other words: To know the basics, which are important for the correct product selection. For this reason Videor Technical offers various trainings to support its customers with basic knowledge for CCTV applications.

CCD Sensors
Basically every CCD Sensor transfers light into electric voltage. They differ regarding b/w or colour, amount of active pixels, CCD format (1/2”, 1/3”, ¼” etc.), sensitivity (e.g. ExView sensor) etc. Within the last couple of years the trend to smaller sensors with the same resolution intensified. But the sensitivity was very often the weak point. Also effects like Moiré, Smear, Blooming and a relatively small Dynamic Range (possibility of a camera to show dark areas as well as high-lighted areas in the same quality at the same time) are more or less weaknesses of today’s products. This is the reason why Videor Technical puts a big effort into comparing different products under different circumstances. As mentioned above the camera is only one important item in a high quality video surveillance system. The lens has an important influence on the quality of system as well.

DPS™ Technology
DPS™ stands for Digital Pixel System and provides for true to life colours under all lighting conditions as well as noise reduction even with little light. Because of the very wide dynamic range (Ultra Wide Dynamic 120 dB) DPS™ camera are insensitive to blooming and smear effects. DPS™ will definitely be a subject that dominates the CCTV market next year. Videor Technical is also working very intensively at the moment on launching suitable products.

Day/Night Cameras
Day/night cameras deliver natural colour rendering during bright daylight conditions. At night or when the light has dropped below a particular level they can switch over to a B/W signal automatically or manually. In order to ensure optimum responsiveness even in the infrared range, this is often supported by a retractable infrared cut filter that eliminates the disruptive infrared light component in daylight. VT has established a wide range of Day/Night cameras for nearly every task.

Day/Night Lenses with No Focus Shift
Lenses with No Focus Shift – possibly supported by infrared lighting – are recommended to achieve optimum results by day and night. As the light spectrum for a day/night application ranges from about 380 nm to 1000 nm, the different sharpness levels (see the illustration) in response to wavelengths have to be compensated for by using day/night lenses. This is achieved by using special glass materials, design and antireflection coatings for lenses (No Focus Shift lenses). The new models with a variable focal length are very popular at the moment – they give on-site installation engineers or users flexibility in setting the desired field of view.

Infrared Lighting
It may be necessary to illuminate the surveillance site with infrared lighting for some applications. The infrared range used for this can be split into two ranges: the semi-discrete range (from 760 nm to approximately 900 nm) and the discrete range from 900 nm that cannot be detected by the human eye. The light source for the infrared illuminator (bulb lamp, halogen lamp, infrared LED diode) is another decisive factor. All models are normally offered in different wavelengths and ranges but they have considerable differences with regard to efficiency and service life. Particular mention must be made here of the LED spotlight that delivers outstanding results with a service life of approximately 100,000 hours.

Day & Night eneo VKC-1317

  • 1/3” Sony IT Super HAD CCD
  • Horizontal Resolution 380 TV Lines
  • Integral Lens F2.0/6 mm
  • Compact Weatherproof Unit including 850 nm Infrared LED illumination (approx. 10m)
  • Automatic Switchover to B/W Signal Output

Day & Night eneo VKC-1319

  • 1/3” Sony IT EXview CCD
  • Horizontal Resolution 380 TV Lines
  • Retractable Infrared Cut Filter (Automatic/Manual)
  • Designed Especially for Day/Night Operation
  • Light Sensitivity 0.42 Lux in B/W Mode
  • Digital Signal Processing
  • Automatic or Manual Shutter Control
  • Auto-Iris/DC-Iris Iris Control
  • 12VDC/24VAC or 230VAC type available

Colour Camera eneo VKC-1322 with RS-232/485 Interface

  • Sensitivity: 0.006 Lux at F1.2 (Sens-up On)
  • Horizontal Resolution: 450 TVL
  • Digital Signal Processing (DSP)
  • Extended Dynamic Range (EDR)
  • Digital Image Stabilisation (DIS)
  • Digital Noise Reduction (DNR)
  • Backlight Compensation (BLC)
  • High-Speed and Low-Speed Shutter Control
  • Automatic and Manual White Balance (AWB/WAWB)
  • Remote Parameter Setting over the RS-485 Port
  • Input Voltage: 12VDC/24VAC