|
Damn - I think I can answer my own question. I just found this below in the fine print on Dons homepage
*********************************** *******************
The Clear (no near-IR blocking) may produce bloated stars if your optical system has poor near-IR focus. Use the near-IR-blocked Luminance filter in this case. The Clear filter is likely a better choice for reflectors, such as Ritchey-Cretiens, rather than refractors or camera lenses.
*********************************** ***********************************
So with a refractor , even a good one, they reccommend the IR blocked Lum filter to avoid bloating - I know I should have known this but it may be a warning to others considering Astrodon E series for these big chips. Save buying 2 Lum filters like I am going to have to
Mark Bolton
|