We present VLT and Magellan spectroscopy and NTT photometry of nine faint cataclysmic variables ( CVs ) which were spectroscopically identified by the Sloan Digital Sky Survey .
We measure orbital periods for five of these from the velocity variations of the cores and wings of their H \alpha emission lines .
Four of the five have orbital periods shorter than the 2–3 hour period gap observed in the known population of CVs .
SDSS J004335.14 - 003729.8 has an orbital period of P _ { orb } = 82.325 \pm 0.088 min ; Doppler maps show emission from the accretion disc , bright spot and the irradiated inner face of the secondary star .
In its light curve we find a periodicity which may be attributable to pulsations of the white dwarf .
SDSS J163722.21 - 001957.1 has P _ { orb } = 99.75 \pm 0.86 min .
By combining this new measurement with a published superhump period we estimate a mass ratio of q \approx 0.16 and infer the physical properties and orbital inclination of the system .
For SDSS J164248.52 + 134751.4 we find P _ { orb } = 113.60 \pm 1.5 min .
The Doppler map of this CV shows an unusual brightness distribution in the accretion disc which would benefit from further observations .
SDSS J165837.70 + 184727.4 had spectroscopic characteristics which were very different between the SDSS spectrum and our own VLT observations , despite only a small change in brightness .
We measure P _ { orb } = 98.012 \pm 0.065 min from its narrow H \alpha emission line .
Finally , SDSS J223843.84 + 010820.7 has a comparatively longer period of P _ { orb } = 194.30 \pm 0.16 min .
It contains a magnetic white dwarf and , with g = 18.15 , is brighter than the other objects studied here .
These results continue the trend for the fainter CVs identified by the SDSS to be almost exclusively shorter-period objects with low mass transfer rates .