Thursday, 18 April 2019

CaK Full Disk 18th April

The ED60 I used to take this image is loaded with spherical aberration at 393nm compared to some of my other scopes that gives a softness to the image that is not really possible to focus or sharpen away.  Today I stopped it down to 40mm in an attempt to improve matters, and while this improved things it is still not a good performer as my 40mm f10, which, I think will become part of the travelling setup.  There was plenty of haze today, which in CaK wavelengths has the effect of increasing exposure time.  This image was taken with the 2x cemax barlow and the FLIR GH3 ICX814 camera along with the home brew CaK filter.