From the January 2016 issue

Concentric contemplation

Astroimager Adam Block challenges you to consider the celestial images you create as art as well as science.
By | Published: January 25, 2016 | Last updated on May 18, 2023
Astrophotography is a complex subject with facets that are tedious and technical as well as subtle and sublime. In this article, I would like to steer clear of the technical side of things and instead consider this kind of photography as an art form that permits expansive degrees of freedom in creative expression.

In the course of processing an image, I find myself deconstructing it into elements that are beautiful even when extracted from the whole. Details, colors, patterns, and even conceptual elements all play a role in the final result. Some objects are captivating not because of their visual appeal, but instead for what they represent.

Constellation Crux star trails
Image #1. To create this image, Stefan Seip slowly changed the focus of his camera’s lens as Earth rotated. This highlighted the star colors of the constellation Crux.
Stefan Seip/
For example, a quasar billions of light-years away — but showing up as just a few activated pixels — may be as joyful as all of the colorful gas in the Orion Nebula (M42). This deconstruction is an important technique in approaching image processing because it allows you to choose the right tools to enhance particular elements. However, this compartmentalization can lead to other avenues of expression.

Some images stick in my head for years. Stefan Seip’s shot of the constellation Crux, the Southern Cross (Image #1) that I first saw in 2004 is one of them. I don’t remember being overwhelmed by it at the time. But it was memorable and became an unconscious inspiration for an image I created more than 10 years later.

Painting with starlight is common and can be simple to do, as the uncountable number of star-trail pictures will attest. Seip’s method of “painting” captured pure star color, which is arguably the most attractive element of pinpoints of light.

Wild Duck Cluster star trails
Image #2. The author created this unique view from an image he took of the Wild Duck Cluster (M11). See for versions with and without stars.
Adam Block
My image of the Wild Duck Cluster (M11, Image #2) does something similar in a different way. I painted with starlight by pointing the telescope at a star cluster and then rotating the camera to create circular star trails. You will not get the same result if you take a picture of a star cluster and spin the image in Photoshop. The brightness of the painted starlight is much fainter because it is moving across pixels at a particular rate. In addition, many stars lie at the same distance from the center of rotation. As the light from these stars mixes, the rings formed by star trails will create a fascinating palette of colors.

This image captures a deconstructed cluster, but star color is only one aspect of it. The spacing between the rings of light emphasizes the stellar density profile of the cluster. The art shines through because the mesmerizing effect of thin concentric circles is hard to ignore. This is a kind of representational art that I find fascinating. Given time, it would be great to make a collection of photographs of different clusters to see how they differ or perhaps leave the collection unlabeled and try to figure out which image matches a particular star cluster.

If our pictures capture Musica Universalis (the Harmony of the Spheres), then the next time you are processing an image, consider the notes that make up the melodies of the cosmos.