Re: [Rollei] How do I use a Rolleinar?

[bigler@ens2m.fr]

  From Vick:
> ...questions on the Rolleinar

> 1)  which lens goes on the viewing lens?  The long "fat" one or the
> skinny one?

The _long_ one (usually stored above the thin one as a compact stack),
goes on the _viewing_ (top) lens. Note that if the bayonet mount is
the same forboth rolleinars, the barrel has a reduced diameter so that
you can mount both lenses on the twin lens bayonets even on a 2.8 TLR
model.

> 2)  is there an "up" orientation?  

Only for the _viewing_ rolleinar lens. The reason is that the viewing
rolleinar is composed of a positive lens element of the same focal
length as the viewing one, _plus_ a prism of a very small angle, its
base being on the bottom side. Now take the viewing rolleinar, look
through it and rotate it. There is only one position for which the
image is not shifted laterally but shifted up. This is the right one.
The viewing rolleinar should be in this final position of course
_after_ turning the bayonet mount in.

> ..a red dot on the lens for the viewing lens, 

Yes the red dot is supposed to tell you where to start when attaching
the viewing rolleinar ; there are 3 positions at 120 degrees, only one
is the good one. The two "wrong" others will yield a lateral image
shift.

> ...There is a red "R" on the black rim of the long lens. There is
> also a tiny grub screw (set screw) on the fat lens that might at one
> time had red paint on it.

I should check this on my rolleinar but those details (the "R" and the
set screw) are not of any importance in normal operation.

- -- 
Emmanuel BIGLER         
<bigler  

------------------------------