All Other: NEWT for Windows

5.0 One of the best tools for the ATM!

Simple; Accurate; Small; FREE

May not print on modern printers

Newt is a program that has been around for many years. It is a highly functional program for the ATM that allows you to calculate the design of a "Newtonian" telescope. The software allows you to manipulate the parameters and see what the changes do with a graphics representation of the telescope. It will help you in determining the effects of changing things such as the size of the secondary mirror or the height of the focuser. It also allows for the calculation of the size and placement of baffles if you choose to use them in your design.

NEWT features:
* Display a side view of a Newtonian telescope.
* Modify parameters like mirror diameter, diagonal minor axis, focuser height, focuser inside diameter, tube inside diameter and thickness, and many more.
* Use inches, centimeters, or millimeters as the unit of measure.
* Calculate baffle size and placement.
* Calculate diagonal offset.
* Calculate fields of 100% and 75% illumination.
* Load and Save files.
* Eyepiece table includes focal length, power, exit pupil, apparent field, and true field.
* Check for minimum usable diagonal minor axis.
* Check for vignetting at the focuser.
* Check for vignetting of true field by top of tube.
* Calculate obstruction percentages for light loss and contrast reduction.
* Cast three rays through telescope - an on-center ray, a 100% light zone ray, and a 75% light zone ray. Use these to check for vignetting at focuser, true field cutoff, etc.
* Print specifications and dimensions to a printer.

Newt works under any version of Windows. I have also used it on Linux systems by running it with the Win emulator. There is also a DOS version floating around and it can sometimes be located on the web.

One problem does exist. As this software is quite old, it was originally designed in the days of "dot-matrix" printers. Its ability to print may or may not work with many modern printers. The software is FREE for download but is no longer maintained.

If you can overlook the printing issue, it is an excellent piece of software, and many hundreds, if not thousands, of telescopes have been built using its calculations over the years. It is still a very good tool and I rate it "excellent", even with the printer problem!