Sunday, 29 December 2013

CaK Full Disk Triband ERF 29th December

CaK-triband-colour by Mark Townley
CaK-triband-colour, a photo by Mark Townley on Flickr.

This was the first outing for my new triband ERF from Oliver Smie at Beloptik; I installed it in the dew shield of my 70mm f6 refractor where it was a perfect fit. Using my using rear mounted homemade CaK filter setup the first thing that struck me was how much shorter the exposure time was probably due to the ERFs transmission of 70% compared to the usual 5% of the solar wedge I was using as a filter. Optical quality is spot on, and later in the year I plan to do a more thorough review at the 3 wavelengths it operates at. I'm pretty pleased with this image - even given the smudge at the bottom of the disk is the branch of a foreground tree.