Monday 12 August 2013

Southern Swathe 11th August

The sun finally came out (in between clouds!) on saturday afternoon here in Anglesey, so I was keen to build on the mornings imaging session where I got a lovely full disk. I tried for some time with my double stack system, however now have a dilemma to solve; If I run the optical train with everything flush there are reflections I need to deal with, I have a perfectly on band double stack image, but there is a ghost reflection partially superimposed over the top of the disk. If I tilt the etalon assembly, then apart from creating a 'sweet band' because it is tilted beyond its operational range then it also causes a shift of focus across the field of view as the refocusing optics are also tilted. So, a problem to solve, I think the route I will follow is to try and find a circular polariser to mount between the 2 etalon assemblies, however this is not straight forward and I need to find one that has a high transmission at ha wavelengths... hmmm... Anyway, after much twisting and tilting I decided to resort back to single stack and got this mosaic of the swathe of activity that has suddenly appeared in the suns southern hemisphere. This was taken with the 100mm at 2000mm focal length using the DMK31 camera. I'm pretty pleased with the detail that has come out!