ZM lens — the most peculiar lens so far

In fact this was not the first time this lens appeared here.   Before, the lens got different guise and used with awkward tilting bellows.   Yet still, using the same approach like the Leiz Elmarit P lens, I wanted to give a new lease of life to this one.

Same as that Elmarit projection lens, the construction was done by just put together readily available component from the Net (except only one glue pont).  (Helicoid ring got 25~55mm extension and able to make 25cm close up for x0.7 image.  Focal length was about 45mm and F2)

As I wrote before, the origin of this lens was not known — probably the front element of a zoom lens.   Under the certain handling, the lens can give pretty good image.

So, it is a sharp detailed image ———  (so far)   😀

However, with a bit different focus, suddenly the lens makes totally different kind of image.   (You may not believe its the same lens) = as you can see the photo right, the depth of field was very shallow and the bokeh (+ halation) is amazingly strong.

Lens seemed to have 2 element still no apparent aberration exists. —– but I can not guess why the lens can make such prominent bokeh where it was not in focus. ( fore-focus seemed to make coma like aberration = So, to make a focus on the edge, the image with bokeh appeared —– as long as it was in the focus, the image is sharp, though, once it was out of focus, suddenly the image became very blurred.)

How strange ? ? ?

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