It is named after the German mineralogist Friedrich Mohs. Here's the scale, from softest to hardest: Talc - easily scratched by the fingernail Gypsum - just scratched by the fingernail Calcite - scratches and is
Slice through negative emotions and toxic ties with the power of Black Kyanite. It is said to protect your energy field from energy vampires (people who seem to always drain your energy), relationships or people who feast on your positive vibrations but offer nothing in return. Purifying your ...
The Kowa TSN-99A Prominar Series is one of the best bird watching spotting scopes money can buy. The TSN-99A is the angled body model, TSN-99S is the straight body model. Crystal clear clarity from Kowa's unique Prominar pure fluorite crystal lenses is just the beginning. ...
Going any lower in power or wider FOV and the edge performance is so messy it's not worth it. Oh and even at F5.9 and using fluorite there is a hint of CA. So an 80mm F4.1 doublet even with FPL-53... oh I'm not sure it would look good. FWIW I love this little scope and...
The FS-78 really isn't really analogous; the $500 Vixen Japan 80mm is an achromat. The Takahashi is a fluorite apochromat. $500 for an 80mm achromat is a lot of money no matter where it's made. Especially since you can get lightly used Japan Vixen and Celestron 80mm achromats from th...
It is named after the German mineralogist Friedrich Mohs. Here's the scale, from softest to hardest: Talc - easily scratched by the fingernail Gypsum - just scratched by the fingernail Calcite - scratches and is scratched by a copper coin Fluorite - not scratched by a copper coin and does ...
The glass is also made with fluorite crystals. The results are fantastic and is why I could max out to 40x magnification and expect tack-sharp resolution every single time. Its off-axis performance was extremely impressive and there was practically no chromatic aberration at all. Though it does...