Some constellations are easier to spot than others. Cassiopeia with its distinctive W is visible year round in the northern hemisphere above the 34th parallel. In the image below it easily stands out from the fainter background stars.
The five stars drawing a W in the sky are all naked eye magnitude 3 and brighter stars, and in the image above I used a layering technique to increase the color and brightness of those stars to really make them stand out.
- Duplicate your base image, and set this layer to lighten only
- Apply a blur to the top layer(about 8-12 pixels)
- Increase the color saturation and brightness. Play with the curves to brighten the bright stars, but not the background sky.
- Use a mask as required to filter out the bright foreground elements, such as light reflecting off a building roof-line in my image above.
Canon Rebel XTi
4 x 20sec ISO800