Annexes; How Does The Lhires Lite Works - shelyak Lhires Lite Guide D'utilisateur

1.16 - Annexes

1.16.1 How does the Lhires Lite works?

This figure describe light path in your Lhires Lite. Sunlight enters
through a slit. There is no optic in front of the slit so it's the relative solar
disk size (around 30' on the sky) which gives the input focal ratio –
around f/50. Light is then reflected by a 45° mirror. It goes through an
optical doublet to bring slit image into parallel beams that are dispersed
by a reflective 2400 grooves/mm grating. Dispersed light goes back
through the lens which focus the spectrum into your eyepiece.
This spectroscope is in Littrow mode – thus the name of Littrow
HIgh REsolution Spectroscope: LHIRES!
By turning the index, you rotate the grating inside and change the
wavelength you look at into the eyepiece.
Lhires Lite – User Manual DC0005C 54 / 60