Warning about Rollei QBM - Sony E adapters

[y]

I wanna share info based on my bad experience with Rollei QBM to NEX adapters.

It seems there are multiple designs available. Some of them should be avoided.

The Rollei QBM mount was iteratively improved. In its second generation (QBM II) Rollei added an aperture coupling lug. This lug is located at lenses base and turns along with the lens' aperture ring.

Many adapters are designed in a way their upper part has four screws which are aligned with the red "mount dot". This unfortunate design choice causes the coupling lug to stuck inside the nearest screw hole and effectively preventing the aperture ring from turning. So you get stuck with f/4 or so.

The troublesome screw hole placement design can be seen here:


A correct design looks like this:


Rollei lens mounting issues can be avoided either by:
- using only the first QBM generation lesnses (which are kinda rare)
- filling that particular screw hole in with clay or epoxy
- using a correctly designed adapter

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Second part of my caution notice concerns directly an adapter made by Pixco wich is sold by various sellers.

Knowing the Pixco quality had been reported to be subpar several times, I got fooled by (fake?) 5* ratings and bought one. The adapter looks good and its finish is high quality. However, its mechanical design is so bad it can't even lock the most common Rollei lens (Planar 50/1. in...

Avoid the Pixco adapter at all costs!

[y]

I have an update to my QBM-NEX misfortune. I've finally bought a new adapter - a cheapo but featuring a proper screw placement design.

This adapter really allows the lens aperture to work freely, unlike the Pixco one. However, its tolerances are so awful the whole lens wobbled during focusing.

So I picked the old Pixco adapter from my junk box, bought epoxy resin and tried to fill the clogging screw hole with it. After a day of curing the adapter started to work perfectly

[aidaho]

I believe there is also a replacement mount in existence, for conversion to EF.
Perhaps this could serve as a more refined solution?

[y]