From the Rooftop

Rooftop Blog

Experiments, build logs, and honest gear notes from a Bortle 9 sky. This is the thorough side of the journey: what I tested, what the data said, and what I'd do differently.

I Tested Every Sub-Exposure Length From My Bortle 9 Rooftop. Here's What Actually Matters.

Six sub lengths from 30 seconds to 10 minutes, equal total integration, one night, one rising target. The result settled an old debate for my sky, and proved my own prediction wrong.

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Altitude arc of IC 1318 with 124 color-coded sub-exposures

Experiment June 2026 9 min read

I Tested Every Sub-Exposure Length From My Bortle 9 Rooftop

Does sub length matter when total integration is fixed? Six stacks, 124 subs, and one flat curve later: an answer for my sky, with the math to find yours.

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