56668main_eclipsemap-large.jpg (JPEG Image, 1942x1465 pixels) - Scaled (53%) Ken's Telescope Calculator. This telescope calculator takes the objective diameter, f ratio, focal length, eyepiece apparent field, and eyepiece focal length as required to calculate the estimated objective performance, telescope magnification, magnification per inch, true field, and exit pupil size. It is a great way to compare the characteristics of different eyepieces. The calculator requires a JavaScript compatible browser.
I have already entered the apparent field for many popular eyepieces from Brandon, Celestron, Meade, Pentax, Tele Vue, and Vixen. You can enter values for any other eyepiece. Enter two of the three values for the objective diameter, f ratio, and focal length, then press Compute to calculate the remaining value and the estimated objective performance. Note: The calculations to estimate the performance of your telescope objective work in units of either inches or millimeters. Unless already entered, type a value for the apparent field and focal length, then press Compute. Telescope Reviews: Viewing list of forums. Augusta Clear Sky Chart. It's the astronomer's forecast.
At a glance, it shows when it will be cloudy or clear for up to the next two days. It's a prediction of when Augusta, GA, will have good weather for astronomical observing. The data comes from a forecast model developed by Allan Rahill of the Canadian Meteorological Center. CMC's numerical weather forecasts are unique because they are specifically designed for astronomers. So, I (Attilla Danko) wrote a script to generate the images like the one above which summarizes CMC's forecast images just for Augusta and the surroundings out to about 10 miles. There are charts for 4699 locations. Summary: In the rows labeled "sky conditions", find a column of blue blocks.
Details: Read the image from left to right. The line, labeled Cloud Cover forecasts total cloud cover. CMC's text page explaining this forecast is here. The line, labeled Transparency, forecasts the transparency of the air. The line, labeled Seeing, forecasts astronomical seeing. Just keep using it. Stargazers Lounge - Astronomy Forum.