whats the difference

[solarandi]

hi everyone

just been looking at ccd's (cost loads) and web cams (fraction of the price)and then thought "whats the difference", surely they are all ccd's. Could you use a ccd to image planets or is a web cam better for this.

any comments appreciated.

many thanks Andi

[Sparrow]

There's a couple of factors at play here IMO:-

Firstly, webcams are mass produced for a large market so the price per unit can be kept much lower than a dedicated astro ccd which will only sell in much smaller numbers - economies of scale etc.

Second factor is that astro ccd's are far more specialised. Many of the DSO ones have built in peltier cooling or at least a fan.

For lunar planetary work it's perfectly possible to adapt some webcams for use with pretty good results. They work on taking large numbers of frames at a fast frame rate - approx 30 per second. The dedicated DSO cameras need to take long exposures of several minutes or more. For this reason they are designed to keep electronic noise to an absolute minimum - not an issue or consideration with webcams.

[ollypenrice]

The chips of some entry level CCD cameras are indeed webcam devices but the cameras are cooled and the electronics designed to permit long exposures. As the CCD cameras get more expensive the CCD chips used in them get bigger and bigger. A webcam chip is miniscule whereas the chip of an Atik 11000 is about the size of 35mm film! Quite a difference, so you can take a much wider field image on the big chip. The chip constitutes most of the cost of the camera, hence the price.

Olly