Let me provide an introduction to put things in perspective and delimit the topic before asking my question. Just move to the next section if you prefer.
Among zoom commands I know:
- Simple "Zoom", accessible by the Wheel, Numpad-Plus and Numpad-Minus), or Ctrl-MMB.
This command moves the standpoint closer to/further from the "view point" (the one used to "orbit" the view). This is somehow confusing, since as everyone knows, in real life zooming doesn't consist in moving the camera, but in changing the camera focal lens (hence, for a given sensor size, the field of view).
Whatever, zoom-in moves toward the view point. As every beginner has experimented sooner or later, one may reach the view point and enter a lock state (following Blender design, moving past this point must be a zoom-out operation, so Blender here just locks silently the command).
Blender "zoom" is actually dollying (a dolly is a cart used to move the camera). Now enters the...
- "Dolly Zoom", accessible by Shift-Ctrl-MMB. From manual:
Blender stores a "view-point" that is used for orbiting and zooming. It works well in many cases, but sometimes you want to move the view-point to a different place.
So using the "dolly zoom" command rather than the simple "zoom" is a the way to not enter the lock state. In a "dolly zoom" one moves toward the view point, but at the same time one moves the view point the same distance.
In addition the field of view of the 3D view can also be changed using the "N-panel" corresponding "lens" value:
This field changes the focal length of the virtual camera used for the 3D view. This actually mimics the real life zoom, but doesn't seem to be used a lot in Blender.
As I understand, there are three factors involved in "zooming" the 3D view: A virtual standpoint location, a view point location and a focal length. I assume here the sensor size is fixed.
Can someone summarize accurately what is scattered in many topics in the documentation, and on this site, regarding the commands used to change these three factors:
Which commands change the virtual standpoint location? (I know Zoom and Dolly Zoom) explained above.
Which ones change the view point location? (I know Dolly Zoom and Center view / Numpad Dot).
which ones change the view focal length? (I know Ortho/Pers / Numpad 5).
For example I don't know what exactly does Reset View (Home) do regarding the three categories above: It moves the 3D view stand point, but does it move the view point location in addition? I'm really interested in understanding more about this (unfortunately invisible) view point. Also feel free to add any zoom related element that I may have forgotten to complete the picture.