Yesterday I was experimenting around H-beta with LHires + 600/mm + 15um slit, got around R~3000 in blue (which I'm satisfied because blue is less good at res. - at blue end, I can't even focus properly all the range).
3 minute exposures, with a few cal. pauses:

- result_psomogyi_20150704_05_Hb_all.gif (1.98 MiB) Viewed 5127 times
Interpolated 3 times a ref.star Iot Cyg.
Took a bit few Ne/Ar manually (hopefully automated today...) but in return, exposures quite continuous with 3 bigger breaks.
Processed by ISIS, other than ref. star interpolation have not touched the continuum.
Note: this is also my lesson to get more precise calibration, after returning to lower it's more obvious...
- Peter