image of render squashed after saving as image

Question

when i saved my render which was in 1:2 aspect XY ratio, it got squashed to the original camera ratio of 1:1. screenshots are given. please help!!

original render

saved image

Answer 1

The Aspect X and Y you can set in the output settings are used if the rendered image is intended for anamorphic display or on devices that have non-square pixels.

The Resolution X and Y is the real amount of pixels in width and height which get rendered (when you set it to 100%), no matter which Aspect you have set. You could say they are more or less independent from each other.

So, with the guess that you have left the resolution at the default 16:9 ratio with 1920 × 1080 pixels, you tell Blender your image should be rendered with this amount of pixels (left in the image below if the pixels were square) but the device where you are watching it will show this with pixels that are just half as wide as they are high (right in the image below), the grid physically having a pixel amount in a 16:9 ratio, but optically being displayed only with a 16:18 (or 8:9) ratio.

Now the problem is, since an image format like JPG or PNG always saves square pixels, in order to get an undistorted output on the device with the non-square pixels, the render camera has to adjust the width of its field of view to the X/Y aspect ratio, so in this case 1/2. Now this is important: it will not render half the amount of pixels in width! It will render 1920 × 1080.

And this means, to have an image of a perfectly round sphere on your device with non-square pixels (left in the image below) the camera has to capture an image with half the width stretched to the full width (right in the image below).

The thing is, and this is where it seems your question is lacking some information, usually by default the render result is shown with square pixels, i.e. as a stretched image in this case like below - and this is how the image gets saved.

But your render result shows an unstretched image so I can only suspect that you have set the Aspect X and Y in the Image Editor to 1:2 as well, to display the image as you expect to see it. However, this is a squashed version of the actual pixels - as it says there in the options, this is the Display aspect ratio. But only the actual pixels are saved with the image, not this squashed visualization because as I said before, image formats like JPG or PNG save square pixels. And this is why it looks correct after rendering but the saved image is stretched.

Answer 2

In the Output panel, make sure that the Aspect XY ratio is 1:1