Webcam long exposures

[burger]

Hi

I am a bit confused about modding a webcam for long exposures,

I have 3 CCD webcams and used them all on sharpcap, I have just left them running on capture for over 30 mins each no problem.

Is this normal or an I damaging them doing this as I see that some have been modded and fans added to cool them.

I am on my second Creative webcam now I screwed the EP adapter in too far and crushed the CCD chip, every day is a school day as they say.

The ones I have are

Creative NX Ultra

Logitech 4000

D-Line netqam

Many thanks

Mark

[brantuk]

Webcam mod'ing is quite a big subject - best to read up on it and come back with specific questions - here's a good link I go back to a lot - there's loads of stuff about the subject and more:

http://www.astronomiser.co.uk/toucam.htm

Hth

[AstroTux]

It will all depend upon what your 'scope/mount set-up is and what you are trying to capure with your webcam:-

If you are trying to capture planets then no modification is necessary as they are bright enough to be 'snapped' as they are. Long runs recording a video file (.avi) will not hurt your webcam. After all, they are designed to be used by people making video calls.

If your are trying to image DSO's then the modifications become useful. If your mount is stable enough and your tracking is sorted then you can use the LX ( Long eXposure ) mod to increase the shutter time from 1/25th of a second ( as used at the 'slow' end of video recording ) to many minutes should you wish. This means that the webcam will gather more light per frame making more detail available on fient objects ( such as DSO's ), but the caveat is that tracking must be spot on and the mount must be stable or you will end up with streaky images.

Modding the webcam with fans, coolers, etc. is done to improve the response of the CCD chip as any temperature variation will cause the chip to respond differently and normally leads to unwanted patches of false light in the image. The is normally the last modification that many will perform and in all probability is only needed after the LX mod has been carried out.

Hope this helps.........

[burger]

Ah

That makes more sense, the one piece of software has exposure as the time you record for, which is why I was getting confused as they all just record as long as you want, and could not see a need for a modification, rather than exposure for shutter speed used which is what I was expecting to see.

Many thanks for clearing that up for me.