Stars With a Reflector

[just_ed]

Currently, I own two small refractors but have been thinking about buying a reflector, so my friend loaned me his 4 ½  inch reflector to see if I liked it. Conditions have not been great, but I was able to view some stars, and was surprised to see that the stars did not focus to sharp pinpoints like my refractors, but focused to little sparkling dots for want of a better description. My friend says that the scope is collimated and that this is normal. Is  it normal?
 

[John]

This is more or less normal. Some long focus reflector designs and those which don't use secondary supports across the aperture can show "refractor like" star images but normally you do see a slightly less tight star image than a refractor will provide.

[jabeoo1]

You are probably seeing diffraction spikes created by the spider that holds the secondary mirror/obstruction in place.  This is normal, however these can vary in their presentation depending on the type of spider.

[AndyWB]

Also, if the scope hadn't cooled, that could be caused by tube currents. That's less of a problem with refractors (I gather).

[Tonys]

If your refractors have small apertures compared to the reflector could it be that the sparkling effect is partly owing to atmospheric disturbance ? Larger apertures show this as movement and breaking up of the dot.