By ghamerly from Waco, TX on 2/21/2008

I bought this solely so that my camera (EOS 40D) could focus at infinity with my telescope (home built dobson 8") and a T-ring. Previously, I could not get the camera close enough to focus at infinity. But with this barlow the focal length is long enough that I can focus the camera.

If I didn't have to use it, I would not, as the optics don't seem great, especially for the price. When viewing near the moon (but not *at* the moon), for example, there is a lot of flaring.
Also, in my case I don't particularly want the magnification that comes with the barlow; I just needed to fix my focus.

By Parsecman from GA on 10/19/2007

Got this to use with my Celestron C-90. When using during daytime would consistently get an image of the center secondary mirror as dark spot/ghost image on the photos. When using just a straight adapter with no built in Barlow this was not seen at all.