Preventing fogging

Often humidity condensates throughout the night. To keep the dew off, we recommend:

1. You can use an M48 extension to extend the objective lens mount. That keeps humid air off the lens and reflects thermal radiation from the lens back to itself. Take at least a 30mm long extension. This will keep dew off for a while, but likely not for the whole night.
2. To safely prevent dew, attach a heater strap around the lens mount. A short strap of 11 or 15cm length and a few watts electrical power is enough.