The Sun - 25th Jul 2015 Ca K Edition

[David Smith]

So, new bit of kit arrived Monday, a Lunt B1200 CaK diagonal. My thanks to the team @FLO for sourcing and at a very competitive price as always. Took a few weeks to get here but sounds like I picked a bad time to order (during summer recess as it were).

 

IMG_0772 by David Smith, on Flickr

I'd read a heap of information online about how Ca K was tricky and most scopes are not well corrected at 393nm, so I was a little concerned that after testing I was going to need a new scope and possibly a new camera as well! Had a quick look through visually on Tuesday but as expected, could not see an awful lot. Forecast of clear skies for this morning meant I finally had an opportunity to try it properly and I have to admit to being both excited and a little nervous. Set my alarm for 6 this morning as best of the clear skies was due before 9. I woke up to exactly that, blue skies and sunshine so wasted no time getting setup.

IMG_0766 by David Smith, on Flickr

The module is designed to work with scopes up to 100mm so I had to create an aperture mask for the Evostar (done in true Blue Peter style with a coffee can and a breakfast cereal box )

IMG_0767 by David Smith, on Flickr

Did some white light work first to get the scope lined up and the laptop up and running and then swapped the white light filter for the CaK module and aperture mask. Slowly bought the image to focus and .....

WOW

The image on the screen was everything I could have hoped for. Bright crisp and full of intricate detail, even with the Sun relatively quiet at the moment. Unfortunately the good clear skies did not last but I took a heap of ser's, many of which I still have to process. No Newton rings (as far as I can tell) with this setup which is a bonus. Exposure times were around 20ms so frame rates were around the 30fps mark. A couple form those I have processed so far below.

This one is a two pane mosaic (yes, you did read that right - mosaic ) using the Revelation 1.25" 0.5x focal reducer

20150725_CaK_FD_0.5 by David Smith, on Flickr

And this one was taken with the Revelation 1.5x barlow.

20150725_CaK_1.5x by David Smith, on Flickr

I have both Ha and white light data still to process later.

As you might expect, forecast for the next few days is terrible, sorry

[laudropb]

Lovely set up you have there. I always enjoy seeing Ca K images and yours is a lovely example. Thanks for posting.

[Tyson M]

Nice. I too hope to acquire that diagonal for an 80 mm refractor someday (and that skywatcher too ). I love Cal K images. I still have so much to learn about solar imaging.

If I am not mistaken, your top FD image clearly shows supergranulation in the Cal K line right? 

[Tyson M]

Faculae on both sides of the limb, plage around the sunspots and supergranulation pattern throughout the disk slowly disappearing at the poles. Great shots. 

[David Smith]

Thanks both.

Tyson - still learning myself but I believe you are correct with the features you have identified.

[Pete Presland]

Beautiful Cal K shots The faculae on the limbs is particularly stunning.

[Montana]

Hooray!! another turned to the blue side :)

Alexandra

[DrRobin]

Superb straight out of the box David. I am still trying to get round and buy one of these CaK modules. That looks like a lot of blue sky you had, someone told me there were torrential downpours at home.

Robin

[David Smith]

Thanks Robin. The blue sky did not last long and it is poring again today.

[Space Cowboy]

Fantastic images with your new setup David!

[Ewan]

You got off to a running start there Dave, well done.

Didn't know Nescafe made a Café Cak scope  , great idea & cheap .......good thinking mate, don't waste astro funds when no need.

I too have been looking at the Cak modules but I am 'into' Ha for now.

Looking forward to you becoming more adept with that unit as I am sure some top images will be presented.

[David Smith]

Thank Ewan. It was a tough call between upgrading my H alpha kit and buying the Ca-K module. In the end lack of availability of the Lunt 50 and uncertainty over Quark quality control lead me to where I am now. That and the fact that there are very few CaK imagers it seems.

Just a shame the weather is so poor at the moment, I'd hoped that bt keeping the purchase quiet the clouds would not notice