Time delay measurements have recently been reported for the lensed quasar PG 1115+080 .
These measurements can be used to derive H _ { 0 } , but only if we can constrain the lensing potential .
We have applied a recently developed deconvolution technique to analyse sub-arcsecond I band images of PG 1115+080 , obtained at the Nordic Optical Telescope ( NOT ) and the Canada France Hawaii Telescope ( CFHT ) .
The high performance of the deconvolution code allows us to derive precise positions and magnitudes for the four lensed images of the quasar , as well as for the lensing galaxy .
The new measurement of the galaxy position improves its precision by a factor of 3 and thus strengthens the constraints on the lensing potential .
With the new data , a range of models incorporating some of the plausible systematic uncertainties yields H _ { 0 } = 53 ^ { +10 } _ { -7 } km s ^ { -1 } Mpc ^ { -1 } .