Thanks gents, especially thanks for the links. It makes for good comparison.
I kinda disregarded the WO type III as it appears to only suit a few scopes. The Type IV appears to flatten well but some do not appear to reduce.
What I wanted was to flatten and give a faster FL...exposure time.
The Astrotech reducers look good as well but I read mixed reviews. The Astrotech version looks like a WO type II. I also wonder if the WO II would work?
I have looked at the
Optec NGUW (.7X). It appears good but not a flattener and limited to 18mm ccds..aka for Sbig ccds.
I think DavidTrap has a TV RFL-4087 as he tested one
here.
Selecting a FL reducer/flattener is more of a crystal ball operation than any absolute facts. Shee's who'd have thunk it.
