Update

Despite our best efforts, some errors may have crept into the text of this book. Here are the ones we have found.

Do not hesitate to contact us if you find other errors that we can report here.

Page 178 – Top of right column

“By pressurizing the air-spacing, changing the index of refraction. Any increase in air pressure will shift the CWL towards the blue wing. Used by Lunt in their Pressure Tuner arrangement.”

must be replaced by :

“By pressurizing the air-spacing, changing the index of refraction. Any increase in air pressure will shift the CWL towards the red wing. Used by Lunt in their Pressure Tuner arrangement.”

Page 178 – Top of right column

“By applying mechanical compression to the air-spaced etalon (in the case of the “Rich View Tuning”), effectively reducing the spacing. Any shift with compression will be towards the red wing.”

must be replaced by :

“By applying mechanical compression to the air-spaced etalon (in the case of the “Rich View Tuning”), effectively reducing the spacing. Any shift with compression will be towards the blue wing.”