Re: Need advice, odd application

In message <[EMAIL PROTECTED]>, Parallax 
<[EMAIL PROTECTED]> writes
> We are using a micro-channel plate followed by a phosphor screen to
> get an image of very low energy (392 eV Carbon x-rays) x-rays focused
> by an ellipsoidal x-ray mirror.  This produces a dim image that
> reminded me of the Ring Nebula so I immediately thought of CCD amateur
> astronomy.  We really need to capture this B&W image and somehow
> integrate over time so we can measure less x-ray intensity.  I can
> imagine integration times of maybe a few seconds.
> We were advised of two possible paths, one cheap and one expensive.
>
> Cheap
> Get a web cam and use it for imaging and use shareware called Lispix
> from NIST to do the integration (downloadable from the NIST site).

Assuming that you are hoping to get some sort of quantitative data out 
of your experiment this method will run into all sorts of systematic 
bias, noise and calibration issues. If it is just for a quick look see 
then fine.
> Expensive
> Get an amateur astro CCD camera with Peltier cooler and do long
> exposures (how long is long and how long is short?)

Amateur CCD cameras are not that expensive in the grand scheme of 
things. Up to about 10 seconds some CCD devices show little dark current 
at room temperature. You might get away without Peltier cooling on 
shorter exposures with a suitable choice of CCD device.

Inbetween the two you can get hacked hardware webcams that permit longer 
exposures but are uncooled. They might do what you want cheaply. At 
least until you have figured out the spec of the actual camera you need.

See for instance the adjacent thread on the Toucam camera mod.

Regards,
--
Martin Brown