The Nikkor-H 5cm F2, later black version is lighter than the F1.4. It is a Sonnar formula lens.
The Helios will need to be calibrated for the Nikon. Not hard to do, easiest way- undo the two set screws, unscrew 1/2 turn, tighten the set screws.
The Helios will need to be calibrated for the Nikon. Not hard to do, easiest way- undo the two set screws, unscrew 1/2 turn, tighten the set screws.