Thursday 15 September 2011

An afternoon in the Sun

On September 09th we observed the Sun in H-alpha at ESAC, in front of Leo's office.

We used Leo's Coronado on Michel's Celestron mount. The attachment point was tied with a hand-made fixation by Manuel, that held well during the observation.

After direct observation through the eyepieces, we tried two types of cameras to capture the images. Here it is a mosaic image of 5 frames (~1 min video), with Barlow and the Toucam.

The image processing was as follow:
  • The original sequence (video) was shot slightly dark not to saturate the pixels
  • The 1 minute sequence was stacked into an image
  • The image was stretched down to DN 85 to enhance the disk features
  • Mosaic was built with Photoshop with slight intensity adjustments.
  • A color map was applied in Photoshop to show in the same image the limb features and the surface details, with a natural color
This image was taken with the Canon EOS DSLR from Manuel (stacking 24 images of 1/20 sec).

Here it is the SOHO EIT304 image closest to the ones above (~18:00 local), for reference.