For this post, I would like to compare the difference in images between the use of a single Solar continuum and double-stacking. In my previous test, I did not find that much difference between those images with and without IR, hence I wanted to know if there was any benefit from using a double-stack of Baader Solar continuum (as I have two of these filters in 2″).
Now there is a 1.25″ Baader Solar continuum double-stack filter available for purchase – in a single filter frame. It is interesting to note that here is not a 2″ version of this double-stacked filter though. For this test, I simply stacked one filter onto the other and compared this to the image taken with just a single Baader Solar continuum + ND 3.0. I used the unmodded Olympus E-P5 with Skywatcher ED80, so infrared was not an issue.
I think you will agree that there is a significant difference in solar details (sun spot and granulation) with the double-stacked filter. This is very similar to the images on the web, where people have done stacking of the best images; do note that the images I have taken are all single images – hence better results can be expected after stacking.
Hence a double-stacked Baader Solar continuum will be my preferred setup from now on. Previously I was intending to sell the spare Baader Solar continuum filter. But after this, I’ve decided to stack them together and use this for future solar imaging.
BTW, I should mention that I contacted Baader regarding how to stack the filters, as their 1.25″ version is said to be stacked at an angle. But they could not help with this enquiry. Hence the fact the two filters are not stacked at an angle, suggests that I am not getting the maximum benefit from the stacking