To me, the main benefit of the double stacked CaK filter is the real increase in contrast it brings. These CaK images are pretty much 'naked' - they were shot with gamma neutral (100) on the DMK31 camera, and the only post processing is sharpening and colouring. They were taken with the 100mm at f10 with the homebrew CaK filter using the Lunt wedge as an ERF. The only problem with this setup is at longer focal lengths and with a lower altitude sun, the exposures are getting too long; this is going to be remedied very soon as I have a triple band ERF enroute from Germany. This will be mounted sub aperture in the Tal 100mm refractor, and with a Moonlite focuser fitted should become an ultimate solar telescope...
