Today and tomorrow (5/11 and 5/12) an extremely large group of

  • Level: High School 
  • Thread starter Thread starter Andy Resnick
  • Start date Start date
  • Tags Tags
    Group
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
Sign up Log in
11 replies · 3K views
Andy Resnick
Science Advisor
Education Advisor
Insights Author
Messages
7,831
Reaction score
4,173
Today and tomorrow (5/11 and 5/12) an extremely large group of sunspots is directly facing the earth:

http://abcnews.go.com/blogs/technology/2012/05/enormous-sunspot-could-lead-to-solar-flares/

I went outside this morning and using a ND 7.0 filter could see it by eye, so photographs could be quite spectacular. Note- if you are not sure what 'ND 7.0' means, then don't risk damaging your eye and/or camera.

Notes: when I photograph the sun, I use at least ND 5.0, no polarizers, but keep the UV filter. The order matters- the UV filter goes at the back end, after the ND filters, to prevent damage. The ND filters have been absorptive, but I just found a reflective one buried in one of the labs which I'll try today. Even at ND 5.0 I have to stop down to f/44 (f/22 + 2X tele) and expose at 1/8000 s. If I want to add a color filter, that goes last, after everything else.

Good luck!
 
Physics news on Phys.org

Discussion



Are you going to try for the transit of Venus on June 5?
 


Whoa:

http://img217.imageshack.us/img217/4374/dsc44051.jpg

http://img98.imageshack.us/img98/3820/dsc440521.jpg
 
Last edited by a moderator:


So I drove to the sea for the sunset and see if I could capture it.

Bummer, the sun hid behind frontal system clouds coming in, before it was dim enough to lock on.

I guess I need that seven stops neutral density filter (ND7).
 


I guess Venus counts as a 'sunspot' tonight- most likely I'll never find out as the clouds are heavy and getting heavier... :(
 


The skies miraculously cleared up right at 6:03 pm. Here's a sample:

http://img812.imageshack.us/img812/908/dsc009811.jpg

My lens is *filthy*- aside from all the sunspots...
 
Last edited by a moderator:


Andy Resnick said:
The skies miraculously cleared up right at 6:03 pm. Here's a sample:

My lens is *filthy*- aside from all the sunspots...
Nevertheless, nice!
 


Beautiful! Much better than the crude pictures that I produced by using a pair of binoculars as a "projector" and photographing the resulting image on a screen.
 


Here's a few more, after some post-processing:

http://img826.imageshack.us/img826/306/montagesmall.jpg

and a close-up just as Venus makes 'second contact'- supposedly it's possible to see Venus's atmosphere, but I'm not sure I can:

http://img690.imageshack.us/img690/151/kisska.jpg

And then a cleaned-up version of the one I posted earlier: I stacked about 40 frames to get rid of the dirt, then added Venus later. One bonus- the solar atmosphere along the limb is visible (at the bottom):

http://img819.imageshack.us/img819/4420/tweaksmalll.jpg
 
Last edited by a moderator: