Thread: AR2738 -Ha and Cak plus prom
View Single Post
  #9  
Old 15-04-2019, 09:22 AM
Merlin66's Avatar
Merlin66 (Ken)
Registered User

Merlin66 is offline 		 
Join Date: Oct 2005
Location: Junortoun Vic
Posts: 8,927
No up front ERF. But the "Cak" filter is actual an stacked assembly of four filters.
The front 2" Baader Blue CCD acts as an ERF, then a 390nm UV cut filter, a 80nm wide band CaK filter followed by the 2A narrowband CaK filter...
Reply With Quote