Male thread - M48X0.75; Female thread - M48X0.75; eliminates a range of focusing problems
The extension tube has a M48X0.75 interior thread and a M48X0.75 exterior thread for elegantly solving spacing problems in astrophotography
Use this extension tube for getting the correct image scale or the exact spacing required for reducers or field flatteners
Really sharp planetary images are only possible using an IR/UV blocking filter; this Astromania filter only allows the visible light between 400 and 680nm through; the UV and IR regions of the spectrum are completely blocked
The advantages in a nutshell: Only lets through visible light; blocks the UV and IR range; particularly useful for planetary imaging with webcams; optically polished and coated; continued in a robust 2inch aluminium housing