[Shiraz (Ray)]

colour cams have about 1/3 the sensitivity and slightly less resolution than mono. They are easier to use than a mono camera setup, since you only take one image (or one sequence of images that are stacked to form a single image) and the colour information is already encoded in it by on-chip filters - one for each pixel.

Mono cameras require external filters to provide colour info which adds to the cost and complexity - but you have more control over the imaging process and get to choose which filters/exposures will give best results for the target and conditions. You can also use binning to increase sensitivity at the expense of resolution if required. However, you must take one image (or image sequence) through each filter and later combine them in software to produce a final colour image, so it's a lot more work.

The total time to gather images through 4 filters with a mono cam will probably end up being a bit less than you would need if using a colour camera (only one image), but there may not be much in it on brighter targets.

Good images can be taken with either type of camera. Some targets require long exposures, but a lot of worthwhile deep space images can be taken in an hour or two with scopes like yours and a DSLR or low end CCD camera - mono or colour. Planetary images require maybe up to 10 minutes. If you intend to image dimmer deep space objects, it is a good idea to get a cooled camera, since you would have to image for a long time to overcome the thermal noise (dark current) of an uncooled camera on faint objects. With their inherently lower sensitivity, colour cameras may be unable to reach the dimmest objects.