When i worked in recording studios, and later taught others, i had an expression that 'the strength of the line is in its weakest component.' An audio signal, flowing through an audio chain towards the ears, could have the finest microphones, pre-amps, eq etc. but be let down by one cheap plug.
Thus i suspect it is with optics, and most other things. The light path has to encounter the finest throughout, including the engineering. For this, much research and development of precision machinery and equipment will be necessary. Hence - not cheap. ED glass is fine, providing it doesn't pass through a bottle-top 2 inches further up the line.
Thus i suspect it is with optics, and most other things. The light path has to encounter the finest throughout, including the engineering. For this, much research and development of precision machinery and equipment will be necessary. Hence - not cheap. ED glass is fine, providing it doesn't pass through a bottle-top 2 inches further up the line.