The native aspect ratio or NAR of the projector is 16:9 or 4:3. It will project the object format as a subset. The image from the projected resolution do not show or reflect the total available resolutions. A 4:3 image on a 16:9 projector is not able to completely use the specified or available space or feature of image to be displayed completely, It may lack in Vertical display or it may lack in horizontal display. The vertical resolution which is 480 to 1080 is used at its max level.
The quality of any projector is measured on the basis of its ability to project the small scale image to the high resolution projection.
In the end, the aspect ratios different to 16:9 (1.78:1) or 4:3 (1.33:1) like 1.85:1, 2.05:1, 2.35:1 or 2.55:1 should be processed by projectors (or HDTVs) because these are the common aspect ratios for films. They are processed through the similar procedure. The difference is only that they have narrow or wide bars above or below the "widescreen' reflection or projected image.
The quality of any projector is measured on the basis of its ability to project the small scale image to the high resolution projection.
In the end, the aspect ratios different to 16:9 (1.78:1) or 4:3 (1.33:1) like 1.85:1, 2.05:1, 2.35:1 or 2.55:1 should be processed by projectors (or HDTVs) because these are the common aspect ratios for films. They are processed through the similar procedure. The difference is only that they have narrow or wide bars above or below the "widescreen' reflection or projected image.