Hello Hening,
Several instances of a possibility here :
Vilhelm
Mr.
NG Supporter
**
Posts: 37
Gone fishing
Re: Voigtlander 125mm f/2.5 APO Lanthar
« Reply #2 on: January 11, 2016, 14:37:42 »
A fantastic lens that delivers both in technical quality (detail, free of aberrations) as well as aesthetic capabilities (pleasant rendering of OoF areas). Bought mine in December 2009, used in a box for 900 EUR. I sincerely can't see why anyone would sell this lens, it is every bit as good as the reviews written about it.
I am aware of the internal construction which makes it prone to loosening and disassembling itself, this was however in my case quite easy to prevent by having a local technician open it and replace the screws, it has worked flawlessly for the past 6 years and I have actively used it for shooting watches and jewellery for clients.
My first instinct though was heavy shutter release finger, or loose tripod or bracket attachment as it seems uni-directional.