Tuesday, April 17, 2012

Sunspots today

A kind soul sent me a 25mm Kellner eyepiece for solar projection purposes for the cost of shipping.  A nice thing about this eyepiece is that the field stop extends quite far from the lens, and will dissipate any sunlight if the sun goes to the edge of the field.

I played with it today to see how far away from the eyepiece I'd need to get to have a 4" image in my 8" F/4.5 (stopped down to two 3" apertures).  Answer: ~26cm.  When I projected the sun on a piece of cardstock, at that size, I was blown away by the richness of the structure of the sunspots today.  And the sun was quite low, as it was shortly before sunset.  Here's today's LMSAL photo.  I saw the two larger groups but somehow missed the smaller group that's down from center.

It's time to build a sun funnel as soon as my projection material comes.

No comments:

Post a Comment