Astrospot Vikerfjell - Best/closest Bortle class 3 site from Oslo?
See map. Vikerkoia https://www.lightpollutionmap.info/#zoom=13&lat=8500088&lon=1112008&layers=B0TFFFFFFF Atlas 2015 Zenith sky brightness information Coordinates: 60° »
FT/HSM motors with focusers of TS/WO/Chinese telescopes
The Optec QuickSync focuser motor series FT20/FT30/FT35 is sold Optec or branded by Starlight Instruments as the Handy Stepper Motor series HSM20/HSM30/HSM35, »
Using Panasonic mFT/mirrorless cameras with Sky-Watcher Star Adventurer mounts
Sky-Watcher sells a range of shutter-release adapters to their Star Adventurer and Star Adventurer Mini tracker mounts, but not for Panasonic. Dosn't matter if the other »
Chasing Astronomical Seeing: Trying global forcast services
If you live in North America, or (to some extent) UK and Australia you have local atmospheric seeing forecasts available, like the Canadian If not, or »
Obtaining correct imaging sensor distance - Backfocus calculation tricks
This writeup originated from a couple of friends asking about "rules" :-) The text applies primarily to optical trains where you have introduced a unit of »