Is the ttartisan 500mm f 6 3 hard to focus manually?

Here is what the site says about that.

From TTArtisan 500mm f/6.3: TTArtisan 500mm f/6.3: A prime lens by TTArtisan for Full frame cameras, 500mm f/6.3. Specs - Maker: TTArtisan - Focal length: 500mm (prime) - Maximum aperture: f/6.3 - Made for: Full frame sensors - Mounts: Sony E, Fujifilm X, Nikon Z, Canon RF, L-Mount, Canon EF, Nikon F - Stabilised: no - Autofocus: no, manual focus What it frames like - On full frame (Sony E, Nikon Z, Canon RF, L-Mount, Canon EF, ...

From Buying used: Checking a camera body: - Shutter count. Shutters wear out eventually. Ask for the count, or read it from a test photo's metadata with an online tool where the brand supports it, and compare with the rated life for that model. - The sensor. Take a photo of a plain sky at f/16 and look for dark spots (dust is fixable; scratches are not). - Ports, buttons and dials. Try every button, the card ...

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