Hi wim, yeah to just elaborate a bit on the above answers - if you want to be get more consistent zooming in, it can help to change out of perspective mode for the 3D viewport. To do that go to Options > View > "3D view projection" and set that to "Parallel". That will change it for the current file. If you want to change it for the initial startup default, save a file with it set how you want and then put that file as the start up template file under Options > General > Template file. The views and styles of the template file will be read in when you start up the program or do a File > New.

A parallel projection viewport will behave in a much more uniform way when doing zooming, zooming in a parallel view is done by just modifying a scale factor value only, when zooming in a perspective view your eye point is actually moving forward or backwards.

You can also get better zoom-in behavior in a perspective view if you set the view rotation pivot point to the spot you want to zoom in on. The rotation pivot will be set to the center of the bounding box of the selected objects if you use the "Reset" button at the toolbar that's at the bottom of the viewport. You can also set it to a specific point location by using the zoom area tool on the same toolbar. If you want to zoom in by just a very small amount the zoom button on that same toolbar can be good for that, click down on that zoom button and hold the mouse down and while keeping the mouse button down move upwards only a very small amount. That will move you forward a smaller distance than the scroll wheel.

re: Export to OBJ is not in a good scale - go to Options > Import/Export > "OBJ options", and fill in the "Scale factor" value there. If you put in a value of 0.01 there for example the exported mesh to OBJ format will be scaled by 1/100 in size just at export time and you won't need to do any separate scaling step.

- Michael