A lightning shot that needs improving...

Any advice? This was taken tonight in Gympie, QLD in the same band of storms that passed over Brisbane tonight.
The EXIF is:
Aperture Value f/5
Focal Length 28.00 mm
ISO 400
Shutter Speed Value 1 sec
The pic is a bit soft, I think I had the manual focus a bit of infinity. :S Any other advice?
Thanks
Tristan
The EXIF is:
Aperture Value f/5
Focal Length 28.00 mm
ISO 400
Shutter Speed Value 1 sec

The pic is a bit soft, I think I had the manual focus a bit of infinity. :S Any other advice?
Thanks
Tristan