[StevenA (Steven)]

Erik, I have the BT200 which is: 800mm f/L at 4.5f (5f). The Barlow is a 2" (Bintel) 2X and when I first told them about it, which was not long ago, they didn't mention or suggest an Extention Tube. I will however get an Extension Tube as it sounds like a handy gadget and useful for other things too (I guess). So far every thing I have bought I have purchased from Bintel, from my 8" Newt' and Mount, all my lenses & filters, Books, etc and then my budget blowing (3 years to save for) EQ6Pro but had never been disapointed. This is the first thing I must say that I have been really unhappy with. It rattled when I fist bought it and had to tighten the thread that held in the lense. I was even told by ***** that sometimes it is required to move the Barlow 'in or out' in Observing in certain situations or for specific reasons. What ever they may be???? Anyway thank you for the advice. The other respondents too. Thanks. StevenA