William Optics 6A lll Variable Flattener/0.8x Reducer

[Dave_S]

As I was seeing Coma with my Altair Starwave 115 APO,  a Field Flattener was required.

 

I decided that it would be useful to combine this with a 0.8x reducer.

 

Looking at the market place, these a varied from 'cheapo' to quite expensive.

 

Having used William Optics kit in the past, and been very happy with it, I bought the WO 6A lll variable flattener/ 0.8x reducer.

 

The build quality is good, with optical quality match, and it gives nice 'clean' stars right out to the corners.

 

Being variable/adjustable makes setting the back focus distance easy, and once set, it locks up securely in position.

 

Unlike some flatteners that attach to the scope via the 2" eyepiece compression type adapter, it screws into the end of the scope' s focuser tube, so no risk of 'Tilt'.

 

The Altair 115 has an M68 thread in the end of the focuser tube, whereas I think M63 is more common. With the flattener being M63, I had to source an M68 to M63 adapter, which I could not find at a UK astro dealer, and so had to get one sent over from Telescope Express in Germany.

 

The 'bottom line' is it does the job well, is of good build quality, and at £179 , is not IMO, overly expensive.