Longslit spectroscopy with HDS

Longslit spectroscopy can be performed with HDS by the use of order-blocking filters. A single echelle order can therefore be dispersed over the full slit length (up to 60''). The following five filters are available.

Filter	Centre (A)	Width (A)
He4686	4688	28.4
O5007	5010	31.7
O6300	6307	29.7
Halpha	6580	54.6
S6717	6728	42.3