Jump to content


Sun 3rd November PST


Recommended Posts

The neighbour's tree has grown significantly this year and already the Sun is getting lost in it at midday so I think it will only be the PST now until February as it fits in tiny places. I had to move 3 times in the hour on Saturday to miss it's waving branches.

First the single stack view and I couldn't tune it as on-band was past the bump stop :( this has worsened since last year too. So only the bottom right is on-band.


2012-11-03 12-31-06 SS by Alexandra's Astronomy, on Flickr

Next the double stack view:


2012-11-03 12-43-02 DS by Alexandra's Astronomy, on Flickr

and the double stack rotated at 180 degrees:


2012-11-03 12-47-28 DS 180 by Alexandra's Astronomy, on Flickr

and a close up with the 2x barlow, I couldn't find any point of focus and the image seems doubled to me:


2012-11-03 f colour by Alexandra's Astronomy, on Flickr

Next a prominence at 2x single stack mode


2012-11-03 13-37-51 f colour by Alexandra's Astronomy, on Flickr

and lastly Calciium K version of a very blank Sun (CaK PST)


2012-11-03 13-05-41 by Alexandra's Astronomy, on Flickr

Camera DMK41, stacked in Registax 5 and wavelets. In the full discs some Smart sharpen was also applied in CS5.

Kind regards


Link to comment
Share on other sites

Hi Alexandra,

You've probably explained this before in other posts, but your Ha full disk shots are taken using a PST with DMK41. So how do you get the PST to focus and how do you reduce the size of the solar image to fit onto the DMK41 chip? I assume you are using a focal reducer, but mine just won't work at all. I can't achieve focus and can only do so with a barlow, which, of course, takes things the wrong way by magnifying rather than reducing the image size.

Sorry for such a basic question, but this is a frustration!! My 150mm Ha solarscope is fine for 'close up views' but I cannot get a good full disk image in one shot!



Link to comment
Share on other sites

Thanks for the nice comments :)

Stu, I think it seems that all PST's are made different. Certainly for around 90% of all PST's just using a short shoulderless nosepiece on the DMK41 works perfectly and it comes to focus, see here (scroll down and it is the first on the 'Accessories for astro camera's' http://www.modernastronomy.com/camerasAstroVideo.html#mintron12v and the image scale at prime focus looks like this on the chip


2011-12-28 11-13-38 by Alexandra's Astronomy, on Flickr

But it does seem that this doesn't solve the problem for the odd PST and DrRobin has a solution for that and I think it involves a hacksaw. I hope this helps a bit :)


Link to comment
Share on other sites


Nice shots for a PST, especially your double stack pics, very nice. I can't really see the double image, but it looks like a feint Newton rings on the 2x?

I know what you mean about neighbours trees, there is one in the garden next east of my observing site which has grown and grown. Apparently there is a preservation order on it, otherwise the neighbour would cut it down. Weill have to have a chat about some pruning.

But the real problem trees are to the south west, that is where the sun is now at 14:30 onwards, so it's a dead loss after then. I was lucky on Sunday, I started at 12:00, put a coat over my scope for 30mins as the fog came down then had around an hour in misty conditions. Today, from work, was better, but only had time for 30mins.

Edited by DrRobin
Link to comment
Share on other sites

Thanks for the tip Alexandra. Short nosepiece solved the problem. First processed image of full disc (ignore the dirty 'blob'), but time was pressing and I didn't have time to clean any surfaces within the light path.

The sun was very low and luckily I managed to snatch this shot as the sun moved between neighbouring trees and a house. My main aim was just to try out the new nosepiece.



Capture 10_11_2012 14_02_13_colour.tif

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.