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       COMMAND

       mmmmaaaakkkkeeeeccccoooorrrrrrrr ---- mmmmaaaakkkkeeee ooooppppttttiiiiccccaaaallll ccccoooorrrrrrrreeeeccccttttiiiioooonnnn ttttaaaabbbblllleeee

       USAGE

       mmmmaaaakkkkeeeeccccoooorrrrrrrr [----nnnn] _c_o_u_n_t

       DESCRIPTION

       Due to the fact that the video camera is sensitive to
       magnetic fields and that it is rotating through the earths
       magnetic field, some distortion results.  This distortion is
       a function of the rotational angle of the arm and mostly
       affects the radial accuracy.  The table has some benefit in
       linear scans also.

       For any given setup a correction table may be made to
       compensate for the distortion.  The table must be remade if
       the digitizer is relocated or adjusted in any way.
       Fortunately it is very easy to make.

       _c_o_u_n_t    The radial _s_t_e_p _v_a_l_u_e to which all other data
                values will be corrected.  Usually obtained using
                the aaaalllliiiiggggnnnn command.

       ----nnnn       Make a null correction table.  The usual table for
                portrait sculpture applications where a smooth
                image is more important than absolute accuracy.

       The factory can supply a jig and accurately machined
       cylinder.  This cylinder is centered in the digitizer.  The
       digitizer arm is rotated to the position at which the
       alignments were made.  The aaaalllliiiiggggnnnn command is given.  The
       number displayed for latitude 255 is noted and the arm
       returned to home.  For digitizers operating in the linear
       mode a planar reference surface is used with a equivalent
       technique.

       Set the sensitivity (_s_e_e aaaalllliiiiggggnnnn) somewhat lower than normal
       so that no noise spikes will be digitized and distort the
       correction table values.

       The mmmmaaaakkkkeeeeccccoooorrrrrrrr command is executed with _c_o_u_n_t set to the _s_t_e_p
       _v_a_l_u_e obtained from aaaalllliiiiggggnnnn.  The digitizer will digitize the
       cylinder and make a correction table.  The correction table
       must be saved with the ppppuuuuttttppppaaaarrrraaaammmm command.

       It is very important that no noise spikes are digitized in
       this pass, so it may be necessary to set the sensitivity a
       little bit lower for this command only.  The command











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       sssshhhhoooowwwwppppaaaarrrraaaammmm ----cccc will display the resulting correction table.
       It should contain a smooth map of correction values with
       most neighboring values differing by no more than 1.

       Any non-conforming values will cause severe problems.  These
       are usually the result of noise spikes in the mmmmaaaakkkkeeeeccccoooorrrrrrrr pass.
       Hopefully all of the values are less than 10, on extreme
       closeups the values may get into the teens.  The correction
       table is stored and retrieved along with the other parameter
       tables with the getparam and putparam commands.

















































