I noticed that when creating an orthographic camera, it “inherits” some properties from the perspective camera it was created from.
Camera A is 50mm focal length, 5 units from the focal point:
If I change the perspective from 50mm to 100mm, KeyShot automatically dolly zooms and sets my camera distance at 10 units to maintain the size of the object on screen. Saving this camera as Camera B:
If I go back to the original Camera A, and change modes from perspective to orthographic, the camera goes to infinite perspective (no converging lines from focal plane to camera in the geometry view), and the Camera position relative to the focal point is maintained - in this case 5 units. I’ll refer to this as Camera A1:
If I do the same to Camera B (100mm focal length, 10 unit distance) and set it to orthographic, I get Camera B1. What’s strange is that this camera is twice as far from the object as Camera A1, but the image is identical:
If I take Camera B1 and make it the same 5 unit distance as Camera A1 (we’ll call this Camera B2), the object now appears as twice the size in the viewport, despite the settings technically being the same:
What’s interesting is the perspective information is “saved” in the orthographic camera, you just can’t see it until you change modes back into perspective. This is Camera A1 switching between orthographic and perspective, note that it keeps the 50mm information:
So not all hope is lost if you are trying to re-create orthographic settings across different cameras, you just have to change them back to perspective to expose all of the relevant information.
I wouldn’t call this behavior a bug, as it seems everything is working as intended. I really like the automatic dolly zoom when changing focal length, and I wouldn’t want to have to manually go around changing camera distances to compensate. I guess orthographic cameras don’t really have an “FOV”, but it does lead to some confusing results when two orthographic cameras can have the same visible settings but different outputs. Maybe the Perspective and FOV information could remain visible, but grayed out while in Orthographic mode? Or we could still adjust the FOV while in Orthographic mode?