AstroGuide:Portfolio Chris Hollander’s Astrophotography
AstroGuide destinations
Processing companion · September 2026
One galaxy.
Three evidentiary views.
A completed Siril session reconstructed from its log, presets, saved products, and timestamped snapshots—showing how two observing eras became a controlled comparison of SN 2026aaiv.
The reading
The strongest decision was to hold the galaxy still.
The final comparison does not develop two complete images independently. Instead, it uses one carefully developed, starless galaxy background and changes the star-derived layer placed over it. That turns a difficult aesthetic comparison into a much cleaner visual argument.
The third state pushes the same idea further: common star-field structure is rejected through PixelMath, leaving the transient as the dominant changed point source. It is visually persuasive—but deliberately labeled as an illustrative composite, not a photometric measurement.
Controlled comparison
Slide across the shared field
Same galaxy background; different star-layer provenance.
“Before” is the saved presentation label. Its star layer comes from the combined master rather than the historical stack alone; the provenance graph below makes that distinction explicit.
Processing graph
Where the session branches—and rejoins
Select a final view to trace only the inputs that produced it.
Session reconstruction
From 1,405 candidates to four presentations
Final set
Four outputs, four different jobs
Reproducibility ledger
The moves worth carrying forward
Interpretive boundary