What is the leica macro elmar m 90mm f 4 good for?

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: What it costs you: - Size, weight and price, especially of the lenses. A full-frame telephoto is much larger than its APS-C or Micro Four Thirds equivalent. - Less depth of field when you want more of it, for macro or landscape.

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