Hi Gina, On your question of buying a webcam it all depends on what you are willing to do. Most of the applications would be for planetary capturing on that particular model you mentioned it would be ideal. now for Guiding and dso yould need a imaging source (DMK) model but it would cost you a little more in the $350 range but its use is more applicable for many things (Guiding, Planetary, Dso) for dso use a monochrome version would be ideal but you would need a color filter set and a filter wheel another $350. But on a color version you could use it as your RGB. So it all depends since you have a Canon 300d use it as your main DSO and the cam as your Planetary and Guider camera. Any other questions feel free to ask . Efrain (Jaicoa)