DS CaK Full Disk 'vs' Solar Dynamics Observatory AIA1700 - 21st September

The above shot was taken with my very recently constructed 'double stacked' filter; this is a concept i've been wanting to realise for sometime now.  Commercial CaK filters have a bandpass of >2.2a, however by stacking 2 of these together in series it should be possible to reduce the bandpass down to 1.5a.  This is well within the performance of many professional observatories world wide and with it should bring advantages over the commercial units.  Yes, there will be a reduction in the through pass of light but this is easy to address with an alternative choice of ERF, however the pluses out weigh this; reduced bandpass means an improved signal to noise ratio for the image, and with it super granulation cells are much easier to see, while still faint prominences and filaments are also easier to see than in commercial form.  Plage areas appear much brighter than usual, and the non active disk is much darker.  

When I looked at the monochrome version of this image I was struck at how much it resembled the images the Solar Dynamics Observatory Atmospheric Imaging Assembly (AIA)1700 camera.  So much so I decided to colour the above image with their palate and do a direct comparison; the image below was taken by the SDO at the same time I took the image above.

Comparing the 2 images directly I don't think the double stack CaK filter is performing too bad, especially when you compare the 2 imaging systems:

The Solar Dynamics Observatory is a NASA mission that was developed by the Goddard Space Flight Institute that sits in orbit above Earth taking photographs of our star at an estimated cost of 817 million USD. 

The double stacked CaK system was developed by me and sits on Earth looking through 300 miles of atmosphere and the optical system for this cost less than 1000 GBP.

When taken in comparison like this, I think the double stack CaK system has a lot to offer and will offer great images for a lot longer than the estimated 5 year life time of the Solar Dynamics Observatory.

Below is my monochrome version of the image which is also very comparable in detail to that of the Paris Meudon Observatory seen below it.

DS Cak Full Disk

DS Cak 40mm f20 colour, a photo by Mark Townley on Flickr.

Taken with the tiny 40mm f10 OTA that makes up the SM40 scope this image shot at f20 shows a surprising amount of detail, recorded using the DMK31 camera.

ar11843 & ar11841 DS CaK 21st September

ar11843 ar11841 DS CaK 100mm f20, a photo by Mark Townley on Flickr.

The sun starts to take on an almost 3 dimensional textured look to it's surface around the limb with the double stacked CaK filter when used with the 100mm at 2000mm focal length. Taken with the DMK31 camera.

ar11850 DS CaK 21st September

ar11850 DS CaK 100mm f20, a photo by Mark Townley on Flickr.

Taken with the 100mm @ 2000mm fl with the DS CaK filter and the DMK31 camera.

ar11846 DS CaK 21st September

ar11846 DS CaK 100mm f20, a photo by Mark Townley on Flickr.

Taken with the 100mm @ 2000mm fl with the DS CaK filter and DMK31 camera.

ar11849 DS CaK 21st September

ar11849 DS CaK 100mm f20, a photo by Mark Townley on Flickr.

Taken with the 100mm @ 2000mm fl, DS CaK filter with the DMK31 camera.

Double Stacked Full Disk - 21st September

DS Ha Full Disk colour, a photo by Mark Townley on Flickr.

The first day of astronomical autumn brought clear(ish) skies on saturday. The sun is quiet at the moment but far from inactive, with smallish active regions, filaments and prominences putting on a show for us.