Recent content by Erwinux

I've built an insulated chamber to protect a sensitive instrument at freeze temperatures in the winter. The instrument is mounted on a telescope, so the heat inside the chamber will slowly dissipate in the ambient. A digital PID thermostat is used to keep the temperature at a safeguard level...

You better use separate lenses to magnify the image. Any curved surface of the pentaprism will cause color aberrations you cannot avoid. Use an achromatic objective and an adequate eyepiece to achieve the magnification you want. The prism should be in between, in the front of the eyepiece. You...