Introduction

Conclusion

The advent of CCD cameras was more a revolution than an simple evolution in the small world of amateur astronomy. CCD sensors  (Charge Coupled Device, the same ones which are used in video recorders) are very sensitive, and they reduce the time exposition in a dramatic way (compared to traditionnal argentic sensors). By the way, they allow to freeze the atmosphere turbulence by using very short exposition in planetary photos. Only few minutes are needed to see very few luminous objects in deep sky observation.There are others advantages with this recent technics : one can see immediatly the image on the computer screen, numerical image processing is very easy and powerful (processing which are often impossible to realize in laboratory for argentic photo). But unfortunately, this techics costs a lot (price of basics commercial camera is approximately $1000) and not very easy to perform for neophyts. I's also possible to use a conventional video recorder or small video camera, which we can now find some performing models. One can plug this cameras to a computer through a video conversion board, but they are generaly expensive.

To begin with CCD, it is possible to use another solution, which is nice and cheap. It's very easy to perform, even for a neophyt. One can find some small commercial video cameras which are directly on a computer (or through a conversio board). They are commonly called ''Web Cam'', as they are generaly used for ''visioconference'' through Internet. Through some small and easy modifications (described in Modification and Adaptation pages) , it is possible to use them for astronomical applications. Different models can be used :

Cliquez iciCONNECTIX QUICKCAM B&W
(320x240, parallel port), unfortunately no more sold ;-(

Cliquez iciCONNECTIX QUICKCAM COLOR 2
(640x480, parallel port), no more sold too arghhh !

Cliquez iciCONNECTIX QUICKCAM COLOR VC
(640x480, USB or parallel port), 490FF.

Cliquez iciCONNECTIX QUICKCAM PRO
(640x480, USB or parallel port), 1000FF.

Cliquez iciCREATIVE LABS WEBCAM 2
(704x576, parallel port), 500FF.

Cliquez iciOLITEC VISIOLITEC MMP-2/VCB2
(640x480, parallel port) 2000FF with modem included.

Cliquez iciAB SOFT VCAM CP-58
(640x480, parallel port) 1550FF

Cliquez iciKODAK DVC 323
(640x480, USB port), 1500FF.

Cliquez iciINTEL CREATE & SHARE YC76
(320x240, USB port), 1500FF.

There is a point important ton note, B&W sensors are generaly more sensitive than color sensors, so they are better to detect dim objects. Moreover, the color sensor needs 3 pixels (with red, green and blue filters) to make a color pixel. By the way, the resolution is lower.

These differences have been noticed with the Creative Labs Webcam II testing. Although this camera has a good quality/price balance, testing revealed that it is less efficient for astronomical uses. But an article written by A.LOPEZ shows that it's possible to obtain some results with the Webcam II.

Some recent testings made by J.F.MOURRON show that the QuickCam Color VC is very efficient for planetary applications. It's currently the camera that we recommend to start with CCD astronomy, and it's quality/price balance is very nice. The modifications for this camera are the sme than the ones for the Qcam B&W. This camera costs approximately 500 FF in France.

H.ZAOUALI uses another camera : the Connectix QuickCam color.

Conclusion

Beginning with a QuickCam is very beneficial, as it's possible to deal with problems which are frequently met in CCD astronomy (focusing's difficulties, difficulties to point an object due to the small size of CCD sensors, etc...) which the real time visualisation gets easy. Comparing the CCD photography to the traditionnal argentic photography shows a much easier performing for the first one, and the faculty to see the image just after taking it gets an incredible feeling. The main interest of the quickcam is to make the first steps in CCD  astronomy for a very cheap cost (for small astronomy clubs or single people). The possiblities are really huge : lunar, planetary or double stars' images,occultation animations, jovian satellites' movings,  planets rotation, and many others... And now, one can find portable PC foe less than $1000 in computer big stores.

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