Practical knowledge of the use of tilting etalons LS 35-40.

[pupak]

For more than a year I have been testing various combinations of etalons and telescopes. I believe that the LS tilting etalons work well as an indoor etalons when the light intensity is not too great. Although the perpendicularity of the beam is important, the intensity also plays a big role. If I use the AR200/F8 at F40, then the LS etalon does not have good contrast even when the telecentric element is used. By applying narrow-band H-a filters or a blocking filter, the contrast will increase, similar to when a cloud passes. As soon as the light intensity drops to a value corresponding to the value for frontal use, an increase in contrast is noticeable. These etalons work just as well on the AR150/F24, where the light intensity is satisfactory on the F48 and quite decent results can be achieved with a pair of LS40 etalons. For these reasons, LSs also work better when paired with Quark as a rear etalon. Quark has quite a lot of attenuation and that suits them. If you use them collimated at F7, the contrast is already so poor that it loses its meaning.
LS etalons have good usability in combination with Quark, or on telescopes with high F. This is my personal experience.