Just want to share some pics of my Patek 5170P display caseback that I took today. This is Patek's inhouse movement Calibre CH-29-535PS. It's a manual winding chronograph movement with column wheel, 30min instantaneous second counter and a 65 hours power ...
both are fabulous movement on their own rights. ALS is a bit 3 dimensional so gain on watch thickness & PP as always likes to stay thinner ! Best, Mahesh.,
I think it is a bit of an optical illusion as actually the Lange is thinner. But only slightly 10.8 vs 10.9. The movement, though, if the Patek is 5.35 vs the Lange 6.1. however cased the Lange is slightly thinner. www.hodinkee.com
They look almost identical from the caseback. Yes, as you said, the datograph has the big date module on the dial side of the movement. That adds some thickness.