I was using a vivitar tripod. It's really light and easy to carry around, I guess that disadvantage comes when you're standing on a 'wobbly' bridge. I was using a remote and put weight on the tripod as well, surprised about the blur :/
Would a lens hood do the trick instead of my hand?
Unfortunately, the image is heavily contaminated by the close by Sodium(?) light shining into the lens and is beyond rescue, I would say. You could apply a cooling filter in PS and mask off the areas unaffected but I doubt you would get very far because of the flare.
Originally Posted by JackoWilliams
In a mixed lighting situation, you can only balance for the main subject in the image. If it can't be got right in camera, correcting for WB and exposure is best done in a RAW converter, it's too late by the time the image is "fixed" and taken into PS. The tone curves for WB vary considerably at different frequencies so it needs correcting at the RAW level to be right.
Fortunately, the human eye/brain doesn't need the WB to be perfect, particularly in a night shot. All we can aim for is a pleasing image without obvious technical flaws.
Sometimes it can be effective to choose an incorrect WB for the main subject to achieve a more pleasing result. In this image I chose the WB for the pre-dawn sky and left the Castle illuminated by the warm floods from the car park which also cast pleasing shadows through the trees.
As it happens, it would be quite easy to correct the WB for both sky and Castle because the two areas are quite easy to separate. In the RAW processor, develop a second image corrected for the car park floods and merge the two images using a mask.