View setting of setup_camera function in O3DVisualizer class

### Checklist

- [X] I have searched for [similar issues](https://github.com/isl-org/Open3D/issues).
- [X] For Python issues, I have tested with the [latest development wheel](https://www.open3d.org/docs/latest/getting_started.html#development-version-pip).
- [X] I have checked the [release documentation](https://www.open3d.org/docs/release/) and the [latest documentation](https://www.open3d.org/docs/latest/) (for `main` branch).

### My Question

The value of filed_of_view in the _camera function does not change the final render image? I set one to 60 degrees and the other to 10 degrees, but the picture is the same.
This is photo with value in 10 degrees.
This is photo with value in 60 degrees.
the code is :
import open3d as o3d
import numpy as np
o3d.visualization.gui.Application.instance.initialize()
pcd = o3d.io.read_point_cloud("D:/MPEG/mpeg-pcc-tmc2/mpeg_datasets/longdress/Ply/longdress_vox10_1051.ply")
box = pcd.get_axis_aligned_bounding_box()
min_box = box.get_min_bound()
max_box = box.get_max_bound()
center = (max_box + min_box) / 2
eye = np.array(center) + np.array([0, 0, 700])
vis = o3d.visualization.O3DVisualizer("3DVis", width=1920, height=1080)
vis.add_geometry(name="point_cloud", geometry=pcd, is_visible=True)
vis.point_size = 2
bg_color = np.array([255.0, 255.0, 255.0, 1.0], dtype=np.float32).reshape(4, 1)
vis.set_background(bg_color, None)
vis.post_redraw()
vis.enable_raw_mode(enable=True)
vis.show_skybox(show=False)
field_of_view = 60.0
center = np.array(center, dtype=np.float32)
eye = np.array(eye, dtype=np.float32)
up = np.array([0.0, 1.0, 0.0], dtype=np.float32)
vis.setup_camera(field_of_view, center, eye, up)
vis.post_redraw()
o3d.visualization.gui.Application.instance.add_window(vis)
path = r"D:\photo\photo2.png"
vis.export_current_image(path)
o3d.visualization.gui.Application.instance.run()