Tom, tpolakis@xxxxxxx wrote: >Stan, > >How accurately do you want the azimuth of your polar axis to be > Getting Polaris in the center of the eyepiece within, say within 15 seconds of time, is easily doable. I just did the azimuth adjustment last night and it was no problem. The error comes in with non-orthogonality of the axis, the center of the eyepiece not being in line with the optical axis of the telescope, and the accuracy of the transit time of Polaris. The first two are difficult to take into account and so I am proceeding assuming the best, for now. The transit time of Polaris appears to be difficult to accurately know. I was not too concerned about how accurate Guide's value was for the transit time when I did the azimuth adjustment last night because I knew I was going to have to go back and tweak it some more after I get the altitude adjustment done. In the meantime I could check out Guide's value, as I have just done through these messages and doing the calculation myself. It appears Guide's value is good. >anybody pitched in yet with a transit time from Guide software=3F The aut= >hor >Bill Gray seems to be the most interested in high accuracy, and I think >it's still the charting software of choice for astrometry types=2E > > From my calculations, which could be wrong, it appears Bill Gray's value is the most accurate which supports your statement that he seems to be the most interested in high accuracy. His apparent RA for the Sun was off by only tens of seconds of time compared to the values given in the 2007 Observer's Handbook, page 158 (of course, this assumes the Handbook values are correct). This is from a program, version 8, that I received 5 years ago! I think this is a good program. Stan -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.