Field Stop SpecificationsPosted By Herbert Kraus |
My thanks to all of you who have responded to my original inquiry about where to obtain field stop diameters of the various makes of commercially available eyepieces. Apparently such information is not readily available, except for data based on the formula that divides the APOV by the magnification power of the eyepiece in question when used in a particular telescope. Unfortunately, I need something more precise than the rough approximation of TFOV yielded by this formula.
I tried a Google search which furnished me two sites that were helpful to some extent:
http://www.astro-tom.com/technical_data/eyepiece_specs.htm contains data for many eyepieces. However,field stop diameters are given only for eyepieces made by Clave, Edmund Scientific/RKE, and TeleVue (which still seems to be the only manufacturer from which this information is readily obtainable anyway).
http://www.petersonengineering.com/spreadsheets/Eyepieces-for-14_inch_SCT.htm does have measured field stop diameters for substantially all of the eyepieces it lists, including Meade and Celestron models, although its list seems somewhat more limited and may be somewhat out of date.
I tried a Google search which furnished me two sites that were helpful to some extent:
http://www.astro-tom.com/technical_data/eyepiece_specs.htm contains data for many eyepieces. However,field stop diameters are given only for eyepieces made by Clave, Edmund Scientific/RKE, and TeleVue (which still seems to be the only manufacturer from which this information is readily obtainable anyway).
http://www.petersonengineering.com/spreadsheets/Eyepieces-for-14_inch_SCT.htm does have measured field stop diameters for substantially all of the eyepieces it lists, including Meade and Celestron models, although its list seems somewhat more limited and may be somewhat out of date.