Had the Explorer laser collumated before i bought it, and it was spot on, out of the box. I agree with you, the difference is only the focal length. Do you think this would make the big difference i'm seeing In the DOB, saturn would go bigger, and crisper, easier to focus, more colour in the cloud belts, cassini definition great views. I'll be talking to the shop tomorrow... what refractor do you use for your planetary viewing Appreciate your replys