Zoooom

Hold Z to zoom in. Let go to zoom back out.

Config

You can change the zoom level and turn on smooth camera in the client config:

[general]
    #Zoom distance
    zoomDistance = 0.23
    #Enable smooth camera while zooming
    smoothCameraEnabled = false

• zoomDistance sets how far you zoom in. The default is 0.23.
• smoothCameraEnabled turns on vanilla's smooth camera while you're zoomed in, which makes turning slower and steadier.