Like many people, I own a variety of old manual lenses. When I'm out shooting, I use various lenses - some are with electronics, some are not. I want to find the photos that come from non-electronic lenses so that I can fix their metadata externally. digiKam has no facility for me to filter by or find photos by lens name, or by *missing* lens name. This is a feature request to let the user filter by lens name, or lack thereof.

Ideally a combobox or list of some sort should show the user a list of lenses used in the photos in the currently open album, so that the user can select one (or more). Here is an example from RawTherapee:
http://i.imgur.com/y0AykOh.png
The "K or M lens" is the tag for photos which were taken using a non-electronic lens.

Reproducible: Always