I don't remember if I have ever posted these here before, but if I did it was a very long time ago. Some of these are worth keeping for you astrophoto buffs out there and I have found the exposure tables to be spot-on. For f/ratios not listed, it is easy to see where to start for bracketing. For solar exposures, non-eclipse: http://www.users.qwest.net/~sherrodstephen/SolarEx.htm [Broken] For lunar exposures: http://www.users.qwest.net/~sherrodstephen/moon2.htm [Broken] For image size on film, CCD, anything: http://www.users.qwest.net/~sherrodstephen/Image%20Size.htm [Broken] For use with the popular nebular filters: http://www.users.qwest.net/~sherrodstephen/knisley.htm [Broken] And the next two are for the "Newtonian guys" who might want to build a scope or make changes to a commercial scope if needed: http://www.users.qwest.net/~sherrodstephen/diagonal.htm [Broken] http://www.users.qwest.net/~sherrodstephen/secondary_offset.htm [Broken] There is one well-known program on the internet named "Scope Design" (or something similar) that is supposed to give all newtonian parameters for tube length, diagonal size, mirror placement, focuser height, etc., etc. but I have entered the info it requires many times and it is just plain wrong! Hope the links I listed are useful to at least some of you, especially beginners. This centerline photo of an annular eclipse was taken using the solar exposure table with no bracketing needed.