It does a great job of effectively replacing all the individual lenses in the 8-24mm range we have. My son and I use it in a smaller Zhumell 100mm dobsobian, and the lens is heavy enough to put a noticeable tilt on the lens holder; not sure if I'd trust combining it with a Barlow of any substantial length. The adjustment ring is also a little stiff (probably a good thing, to prevent over adjustment), but does make finer focusing a little difficult.