A Test with the new Telescope (Messier 81)

On Sunday, December 14th, I captured an image of Messier 81 (M81), which is also known as Bode's Nebula.

M81 is not a nebula, but is in fact a barred spiral galaxy. Bode's Nebula was catalogued as a nebula by early astronomer Charles Messier. At the time, there was a misconception that there was only one galaxy: The Milky Way. In 1924, Edwin Hubble was the first to prove that some of these faint objects, which were classified as nebulae, were in fact "island universes" (the use of the term "galaxy" wasn't used for other objects until the mid 19th century).

We are blessed to live in an era in wich we can observe these galaxies. We see M81 on its "face" side, meaning that we can see the core of the galaxy. This gives us a wonderful opportunity to study the core, the spiral arms and the globular clusters that are in and arround M81.

These images was taken with a 1980's C11 Schmidt-Cassegrain telescope and an ASI533mm Pro camera. Compared to the famous Newtonian telescope design, the Schmidt-Cassegrain gives the unique advantage of a longer focal length (meaning, higher magnification), while keeping the overall length of the telescope down by about 80%. This assists with balancing the telescope and making it less of a "wind sail". The camera is a monochrome square-sensor. This means that the images are naturally black-and-white, so I had to take three images (actually a lot more), each through a different filter, to get an RGB image (naturally the filters used were R, G, and B). To add more detail to the image I also photorgraphed through the Luminance (or L) filter, which results in an LRGB image. The Luminance image is colorless and is not intended to enchance the color in any way. Instead, the Luminance file increases the detail and SNR dramatically in the image (for technical reasons that I won't go into right now, this is an advantage over One-Shot-Color (OSC) cameras). This results in a balanced image, with color in the shadows as well as the highlights.

This was a fun project. I am new to monochrome imaging, and yet I am pleased with the results. I hope you enjoy the image as much as I did!

Feel free to leave a comment or question below.

PS. I have two versions of the picture. Image 1 or Image 2? Comment below on your thoughts, I'd love to know!

Image 1

Image 2