What is the sony fe 100mm f 2 8 stf gm oss good for?

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From Sony FE 100mm f/2.8 STF GM OSS: Sony FE 100mm f/2.8 STF GM OSS: A prime lens by Sony for Full frame cameras, 100mm f/2.8. Its apodization filter makes very smooth out-of-focus backgrounds, at the cost of light (T5.6). Specs - Maker: Sony - Focal length: 100mm (prime) - Maximum aperture: f/2.8 - Made for: Full frame sensors - Mounts: Sony E - Stabilised: yes - Autofocus: yes What it frames like - On full frame (Sony E): as marked, 100mm. - On APS-C ...

From Focal length converter: Focal length converter: A focal length is a property of the lens, but how much of the scene it shows depends on the sensor behind it. A 50mm lens frames like a 75mm on full frame when it sits in front of an APS-C sensor, and like a 100mm in front of Micro Four Thirds. To compare lenses across systems, convert them to the same format; full frame is the usual reference.

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