(Maurice Gavin) wrote in message
...
On 24 Nov 2004 09:27:52 -0800, (Daniel Cervantes)
wrote:

I am looking for a light bucket to do spectrometry.
Daniel Cervantes

If the [stellar] image is not pin sharp onto the spectrograph slit
then energy is wasted and exposures become exceptionally long.

I'm assuming you want to try long-slit spectroscopy, in which case, it's
worse than just inefficient to have poor imaging. You lose resolution in
the wavelength direction (since each wavelength contains an image of the
illuminated slit), and it also gets harder to do sky subtraction.

The best spectra are made by dispersing good images.

--Pete