Focus the 1.2m manually

You can use a script called testfoc which takes 3 arguments, numframes, exptime and stepsize. For example, testfoc 8 2 15 will produce a frame name 0002.FineFoc.fits which contains eight exposures of two seconds each, with a focus offset of 15 steps between each frame, and will then prompt the user for the number of the in-focus image and set the focus to the correct value. The command nfoc is equivalent to testfoc 8 2 15.

If your roots are very deep, follow the old method and take manual focus frames thusly:

1. Determine the appropriate exposure time for a star in your favorite field and place the star in the middle of the CCD. Make sure the star is NOT one of the entries in the bright star catalog!
2. Move the focus 0.076 mm (60 of the old units) lower than the suspected true focus. Please visit the HEXAPOD description.
3. In the Telshell window, type go n, where n is the exposure time.
4. After the beep, offset the telescope about 15" west, and move the focus up about 0.025 mm (20 of the old units).
5. type go n again. repeat 3 & 4 about six times, leave a double offset for the last exposure.
6. for the last exposure type total m*n, where m*n is the total exposure you expect (the TCS will tell you this). If you don't want any more exposures, make m*n equal or less than the current exposure time.
7. The chip will now be read out. You have created multiple exposures of the star at different focus settings, which can be inspected via the imexamine routine for the best focus.