Welcome to SGL As a general rule of thumb, you want to be using low magnification eyepieces to look at deep space objects (higher mm value on the eyepiece). Using higher mag eyepieces reduces the amount of light getting to your eye. Bright planets like Jupiter aren't as much of a problem and you can use higher magnification to start to look for detail. The brightness you see is directly linked to the aperture size of your scope (3 inches in your case). The higher the aperture, the more light your scope can gather, and the brighter the object in the eyepiece.