About Canon L1-L2 shutter speeds

[SyPat]

Does anyone have an explanation for the fact that the speed progression with the L1-L2-L3 shutters is not straight with a rise below 1/60?
I get a good correspondence according to the standards between the selected speed and the real speed at each degree, but down from 1/30 everything becomes faster: 1/30 is 1/47, 1/15 is 1/29 and son on.
I observe the same thing on the L1 and on the L2 (whose mechanisms are a bit different) without understanding well. The service manuals are goods for repair but not for adjustment.

 

[Timmyjoe]

I think your slow speed escapement is out of adjustment. On my L2, the speeds go down linearly. Right thru the slow speeds. 1/60 is spot on, 1/30 is 1/27, 1/15 is 1/17 and so on. Maybe time for a service.

Best,
-Tim