Frequently Asked Questions

Here are some of the things which are most frequently asked for
IMACS (and LDSS) mask generation software support.

1: I don't get any objects for my mask, they all seem to be removed for conflicts. Where are they going?

If you have checked for the obvious things such as an error in entering
the field center (look at the sky window, and enable plotting of the
objects to see that they are in the field) then the next probable thing
is that you have too large a wavelength range, or too high dispersion.
Use a greatly reduced wavelength range, and turn off the extra orders
option, and you should see some objects selected. If that fails, check
your slit dimensions, or use the default slit sizes to start. Once you
have the objects appearing, change your wavelength range and slit sizes
to get your desired mask. If extra orders is used, slit images will
conflict with themselves if the ratio of low to high wavelength ends
exceeds the ratio of adjacent spectral orders, which removes all objects.