SIDO

Sorry for the late reply just caught this, no I wouldent say barlows are bad just need to use them within the constraints of the seeing conditions and your telescopes highest useful magnification, conditions will always dictate useability so if using a Barlow gives a blurry view successive longer focal length eye pieces should then be tried with the Barlow until the view is sharp hard to do of course with a limited eyepiece collection. A zoom can be used with a Barlow wich is many eye pieces in one and usually are 8 to 24mm so it is a long and short focal length eye piece all in one, always make sure to refocus after adding the Barlow and as well when changing from one eye to the next as all eyes will have a slightly different focus so this means your son should do his own focusing when at the eyepiece. Hope this helps, if you need further assistance just ask ?

       Again Best of Luck!

                      Freddie...