Pleiades Rising

This is the last series of images I took for the night. The image contains thirteen photographs taken at 1 minute exposures right after each other. I stacked them in Photoshop CS4 using the following process.

 

I've made a note of where you can see the star cluster named the Pleiades rising from behind the dome.

 

---------------------------------------------------------------------------------------------

 

This was taken on National Astronomy Day 2010 at the George Observatory in Brazos Bend Park, near Houston, Texas.

 

Rachel, Buddy, and I arrived around 2115 hrs (CDT) and headed up with our cameras and telescope.

 

---------------------------------------------------------------------------------------------

 

Post processing:

 

- Open first image.

- Copy second image on top of first one.

- Set blend mode to screen (multiply can work in some cases, but I used screen for this).

- Adjust opacity of top layer to around 50% (I set mine to 40%).

-- Occasionally I would use the Magic Wand tool to select the sky, invert the selection to the dome, and erase the dome from the layer because too much red was being added every time I added a new layer.

- Flatten image.

- *Repeat process with next images*

- Once you have a final image, then use your favourite noise reduction tool or application. I just used the one in Photoshop and it did a pretty decent job. I actually used the advanced noise reduction tool so I could reduce more noise on the red channel than on the green and blue channels.

- The last step I did was adjust the levels just a tiny bit to make the blacks slightly darker.

 

Thanks to Don Taylor of the Huntsville Amateur Astronomy Society for providing me with the following details on how to create good star trail images.

Done