Bosch LTC 0489 Dinion 2X

28 Apr 2010
by: By Les Simmonds
In these times of dramatic CCTV technology changes we will be testing two high performance analogue cameras. Following tests this month, and next month, we will carry out tests on several selected new technology, high performance IP cameras.

THIS month we will carry out basic objective tests on the Bosch LTC 0489 Dinion 2X Day/Night camera. It uses a 1/3-inch, wide dynamic range CCD sensor and incorporates advanced 20-bit digital signal processing for improved picture performance and the 2X-Dynamic technology extends the image dynamic range.

 

Our analogue CCTV camera tests will comply with the European Standard EN 61146-1 Video Cameras (PAL/SECAM/NTSC) – Methods of measurement – Part 1: Non-broadcast single-sensor cameras. This standard is also known as IEC 1146-1 and BS EN 61146-1 and is accepted world wide as the preferred method of testing single chip CCTV cameras and it is suitable and preferred for all current colour or monochrome single chip cameras.

The camera

 

Valued features of the Bosch LTC 0489 Dinion 2X Day/Night camera include:

* Detail in Extreme Lighting: In some lighting conditions, the difference between the brightest and the darkest parts of a scene can be extreme. The Dinion 2X generates two images; one long exposure to resolve details in the scene’s darkest areas, and one short exposure to resolve details in the scene’s brightest areas. The Digital Signal Processor (DSP) combines these dual shutter images, from each exposure to produce the most suitable image.

* 20-bit Image Processing: The digital signal processing optimally captures the detail in both bright highlights and deep shadows simultaneously. By combining 20-bit image processing the Dinion 2X maximizes the information visible in the picture even with strong backlighting.

* Wide Dynamic Range: The 2X-Dynamic and SmartBLC, using 2X-Dynamic technology, pixel-by-pixel analysis provides the user with detailed image information and SmartBLC is used to automatically compensate the image without the need for any set-up.

* Lens Wizard: The Dinion 2X camera auto detects the lens type (manual iris, DC iris, video iris) or it can set manually. The lens wizard can be used to back focus the lens with maximum iris opening so the lens will maintain focus through all lighting conditions over a 24 hour period.

* Cable Compensation: The cameras include built in and menu controlled cable compensation which eliminates the need for an additional equalising amplifier on long coaxial cable runs. The cable compensation can be switched off, or set for various equalising levels and can be adjusted over a wide range.

 

Our tests showed that there is a degree of cable compensation even when the cable compensation is switched off. This can add overshoot and undershoot to the video signal with very short cable runs as can be seen on the waveform images. Our tests suggest Bosch has set the off position cable compensation to suit coaxial cable runs of about 100 metres, which is about average.

 

The overshoot and undershoot from this camera is very clean and does not detract from the viewed image but is noticeable when the camera is connected via 1.5 metres of coaxial cable to sensitive test equipment.

It is interesting to note that the European Standard EN 61146-1 Video Cameras (PAL/SECAM/NTSC) – Methods of measurement – Part 1: Non-broadcast single-sensor cameras state the following in a footnote for the overshoot and undershoot tests: “To improve the apparent sharpness of the visible picture, some cameras may produce an overshoot at the edge of a bar signal. Taking this into account, it should be noted that a smaller amplitude of overshoot and undershoot does not necessarily indicate better picture quality”.

 

The tests

 

This series of tests shows the camera test chart with a yellow marker showing the approximate position of measurement on the camera test chart in relation to the waveform image. This will assist those who are interested in the test chart position these test measurements are made.

The tests were carried out on this camera with its default (out of the box) settings, except for the lens wizard, which was set for a manual lens to suit our high performance Schneider test lens.

 

The sensitivity according to EN 61146-1 standard for the Bosch LTC 0489 Dinion 2X Day/Night camera was found to be 4.6 lux. This figure is normal with most cameras because sensitivity test references and standards are rarely quoted by manufacturers these days. We also noted that the day to night changeover happened at 16 lux which is according to the EN 61146-1 standard.

 

The resolution was 520 TV lines which is close to that specified by Bosch. The waveform image shows a depth of modulation of about 15 per cent at 520 TV lines which is three times more than the 5 per cent depth of modulation specified in EN 61146-1. (Note: The tested figure of 520 TVL against the Bosch specified 540 TVL may be explained by our method of splitting the Luminance (Y) and Chrominance (C) signals for our measurements, rather than relating to camera performance, or the performance of our high quality Schneider test lens).

 

We found the greyscale of this camera to be well within specification and more linear than many we have tested. We did note some black stretch which improved black detail. We included an image and waveform of the overshoot mentioned above. This apparently complies with the EN 61146-1 standard and improves the apparent resolution to the eye viewing a CCTV monitor over a normal coaxial cable length.

 

In the next issue we will test another top preforming analogue camera and in a separate article compare its back light performance with the Bosch LTC 0489 Dinion 2X Day/Night camera and then, in the months following, test several selected new technology, high performance IP cameras.

 

 

*Les Simmonds is an independent CCTV consultant. Email: les@cctvconsultants.com.au