After a few minutes' exposure and simple image processing, deep sky object appears nicely on the screen. The quality of the images rivals those seen through large telescopes situated in dark, remote observatories. As my interest is in aesthetic observational astronomy, I use a color CCD that produces color images without complicated tri-color imaging. I hope to share with you my experience so that you could also enjoy the best show the nature provides. A larger scope that captures more light can overcome this noise problem and improve the quality of image tremendously.
Longer exposure can do the same but it imposes stringent requirement on the equatorial mount.
If you increase the exposure above 4 or 5 minutes, guided exposure is imperative. It means that we could take good quality pictures when the seeing is good and we could see all the deep sky objects with the help of a CCD camera. Since the object cannot be seen with naked eye, we have to estimate its position by looking for faint stars surrounding it. The larger the aperture of the finder scope, the easier it is to estimate the position of deep sky objects by star hopping because we can see more fainter stars. The field of view of a finder scope is around 6 degrees, it cannot be used to locate an object precisely.