Sunspots!!!!!

Finally I get to try out my Herschel Wedge on a nice set of sunspots.

http://www.sunspot51.com/Solar/Recent/Sun032508-04pro-2.jpg

http://www.sunspot51.com/Solar/Recent/Sun032508-05pro-1.jpg

http://www.sunspot51.com/Solar/Recent/Sun032508-06pro-a.jpg

And a puzzler. Obviously Newton's rings are coming from somewhere, but I'm not sure where in this H-a image.

http://www.sunspot51.com/Solar/Recent/Sun032508-08pro.jpg

Paul

Great shots Paul! 8)
That last one is an oddball for sure... those rings seem to be some sort of interference?

NICE SHOTS MATE!

The white light ones are great;

As you point out, the h-alpha shows the solar imager's nightmare: Newton rings
There are very few things that can really explain those, apart from a particularly unlucky camera/filter/focal length combination.

I believe that you may have changed something in your settings and that something may have determined the appearing of the rings. I can tell that something is changed even because the contrast in that shot isn't quite right.

I say this because I had something similar happening to me and then I found out that it was a tilting problem (I had to tweak the T-max to tilt the etalon a little bit).

However, Newton rings are a very difficult problem to cope with: Some of my shots show them; others don't. Luckily, most of them don't I'm experimenting lately with a "flat field" type frame, but I can't say that the results are satisfactory for the time being. If I'll ever succeed, this list is the 1st that will know about it, but don't hold your breath

Ciao Paul

Luca