Fitting baader focuser

[lhuchison]

I've just fitted my new baader steeltrack focuser to my EdgeHD 8in. I removed the large nut actually on the back plate, which the visual back used to screw on. The baader sits flush with the back, which seems good in regard to the optimum distance required (5.25in).

Have I fitted it correctly? I ask because on the baader site they say it has a 2in fitting for the 8in and 3.3 for larger scopes.

With the nut removed, it leaves a 3.3in screw fitting. Does the nut hold something essential ? Hope it doesn't all fall apart!

I am unable to test it properly due to the never ending rain and gales!

[ChrisLX200]

It is optional which you use, smaller scopes only have the 2" fitting. However, using the large dia. thread is just one less connection to work loose between your focusser and scope. The limiting factor for vignetting is usually the diameter of the tube the primary slides on, so there isn't much advatage in that sense by using the larger dia. thread. Nothing is going to fall off by unscrewing the visual back adapter plate

ChrisH

[lhuchison]

Thanks Chris, that's put my mind at rest. After buying and fitting , I started to read that there could be a problem with back focus, reduced light, etc, but the length of the focuser is the same as the original nut plus visual back. I'm sure there's a downside but I hope not enough to remove it.