| review: Digital cooled CCD Camera Nova237 from G. Fischer (appr. € 1040,-) |
The Nova237 is an Astro CCD-camera which actually wasn't ment to be.
After many years of being busy with film astro-photography I came to the point where any other progress meant new and most of all more expensive equipment.
The CCD technology offers totally different possibilities.
High sensibility of the CCD sensors and direct availability of a picture opened new dimensions to all astro-photographers.
If … well yes, if it wasn´t for that outrageous (astronomical) price!
For me that was exactly the impuls to develop a new camera with required efficiency and most of all decent price, that would fit CCD sensors of TC 237B Texas Instrument.
After almost 8 months the first prototype was ready to go. Huge demand after presentation of my project on www.astronomie.de encouraged me to assemble a small series of 10 cameras.
The CCD camera contains 2 modular units, namely a head of the camera and an interface unit.
In the head of the camera are located its control electronics, 2-stage Peltier-cooler and 16 bit AD converter.
The interface contains interconnection to a PC, power supply and regulation for the cooling.
Of course, in the Nova 237 can´t be missing an interconnection that allows using it as an autoguider.
Locating the electronics into the modular units brings even more advantages.
One of them is that the head of the camera can be relatively light (together with 1 1/4 inch adapter is only almost 500 g to be added).
Another advantage, and that ist the most important one, is the possibility of upgrading the camera using bigger chip with little cost.
The headunit itself is stored in a massive black aluminium case with eloxy coating.
Thanks to spacious cooling units and 2-stage Peltier-cooler the sensor can be cooled down up to 45 degrees below the ambient temperature and also keep that temperature for a long time.
The maximum temperature fluctuation is 0.3 K only.
The modular units are connected with cabels with 25 pins.
The whole system is determined for mobile use.
Therefore, a simple 12V power source (e.g. car battery, mobile power pack) is fairly sufficient.
As was mentioned before, the Nova 237 is compatible with CCD sensor made by Texas Instruments, that is also compatible with other cameras (SBIG).
The active (light-sensitive) surface of the chip (4,8 x 3,7 mm) contains 658 x 496 pixels.
Photoelectric yield (Quantum Efficiency) lies in average at 35 % and drops in the total visible range by only a few percent.
In case of TC237B we talk about so-called "frame transfer" chip.
This kind of sensor can act as an electronical shutter with exposure lower than 1/100 sec.
This will, of course, effectively suppress the notorious "smearing" caused by bright objects.
You can put on/off anti-blooming modus as you wish.
Technical specification
- 658 x 496 pixel
- Pixel size: 7.4 x 7.4 uM
- Chip size: 4.8 x 3.7 mm
- Read out noise: appr. 28 e- RMS
- Full-well capacity: appr. 30.000 e-
- Dark current: 1.8 e-/s/pixel
- about 35% overall quantum efficiency
- AD-converter: 16 bit
Service / Support / Contact
Nova Homepage nova-ccd.de
Camera comes with head, interface box, cables, 1 1/4 inch adapter and the control software.
Example Image
M57, Nova237 at 2x2 binning, Celestron C8 at f/5.9, 10 x 60 s exposure
Search more images taken with the Nova 237
by Gerhard Fischer
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