Well, i started commercially with computer animation in 1984. And i know for sure that the differences between frame rates are not balanced by duplicating images. Try it out - you will definetly see it. Frames - fields. Each video image (frame) is in fact divided into two images each with half the resolutions. Fields. Normally one contains the even scanlines, the other the odd ones. But you can have access to each field with professional video equipment. Therefore it makes sense to render 50 images per second (PAL/Secam or 60 (NTSC) to get smoother movements. I am very surprised that the apsect ratios are not rendered right - when you enter specific values. I will try that.

One day your ship comes in - but you're at the airport.