You asked
Is the leica macro elmar m 90mm f 4 worth it?
Here is what the site says about that.
From Leica Macro-Elmar-M 90mm f/4: Leica Macro-Elmar-M 90mm f/4: A macro lens by Leica for Full frame cameras, 90mm f/4. A collapsible, light 90mm. Specs - Maker: Leica - Focal length: 90mm (macro) - Maximum aperture: f/4 - Made for: Full frame sensors - Mounts: Leica M - Stabilised: no - Autofocus: no, manual focus What it frames like - On full frame (Leica M): as marked, 90mm. Cameras it fits - Leica M9: Full frame - Leica M9-P: ...
From Sensor sizes: Is full frame worth it?: For low light, events, and portraits with very shallow depth of field, yes. For travel, street, wildlife on a budget, and most hobby photography, a good APS-C camera with good lenses is enough, and you'll carry it more. Lenses and light matter more than the last stop of sensor performance.
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