RealSense D435 FOV disceprancy of depth cloud and laser of depthimage_to_laserscan

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Hello guys,

I am using an Intel Realsense D435 depth camera with the realsense2_camera package , converted the depth cloud to a laserscan via depthimage_to_laserscan package.

I launch the camera with

roslaunch realsense2_camera rs_camera.launch align_depth:=True

and the laserscan with

rosrun depthimage_to_laserscan depthimage_to_laserscan image:=/camera/aligned_depth_to_color/image_raw

to get the depth module aligned with the RGB module, so pixel XY in depth corresponds to the same pixel in RGB. When I show both the depth cloud and laserscan in rviz, there is a difference regarding the FOV. That difference happens when I choose the aligned_depth_to_color topic for the depth cloud display in rviz, but not when I use the regular depth topic, which is not aligned. According to Intel, the D435 has a horizontal FOV of approx. 87° for the depth module, which I can pretty much confirm for the first image below/aligned_depth_to_cloud. An echo to /scan topic shows me

angle_min: -0.473687112331
angle_max: 0.481075167656

which is approx. 54° in sum.

Its obviously logical, that the FOV decreases when it's aligned to the RGB module. But why is rviz showing me a wider FOV for the aligned topic and narrower for the not_aligned topic, it should be exactly the opposite??

The first picture is depth aligned to color, where the depth cloud is clearly wider.

The second picture is not aligned; it isn't noticeable, but from a different angle you can see that they have the same width

Thx in advance