Nikon 24-70mm Fine tune surprise

I have owned my Nikon 24-70mm f2.8 for the last three years and have been quite happy with its performance.

With a recent purchase of a D800 and knowing how it can be unforgiving with lenses I had noticed a degree of softness in my images particularly with this lens wide open.

I tested it with the FoCal software yesterday and have discovered that at 50mm and 70mm it needs -10 to be in sharp focus at 2.8. This drops to -3 at 35mm and 28 and 24mm need no adjustment.

Adjusting to -10 at 50mm and 70mm makes a clear difference but it does obviously mean it softens up the wide angle a bit.

Am thinking that a compromise of -5 will not badly affect the wide end but still give some improvement at the long end.

I wasnt much into the idea of fine tuning lenses but this proves to me it can make a difference.

For information as well I tested my 85mm f1.8 and 50mm f1.8 and the software recommended no change for those