When you render a scene in Blender, by default there will open a small window showing your image. If you want to publish your picture, you may want to render it a bit bigger. To do this, you have to open the Scene context (F10) and locate the Format sub-context (usually on the right).
You will see some settings there. Let's go through their meanings:
- SizeX: This parameter sets the width of the image in pixels.
- SizeY: This parameter sets the height of the image in pixels.
- AspX, AspY: These parameters specify the aspect ratio of the pixels. By default, this is 100:100, because a pixel on a computer screen has equal width and height. These settings can be used for screens whose pixels don't have equal width and height. For example, on a PAL system one pixel's width/height ratio is 54:51, which you can select there easily. Notice that these parameters don't change the size of the image.
There is one more thing changing the render size: In the Render sub-context (usually in the middle) there are 4 buttons: 100%, 75%, 50%, 25%. If you have chosen SizeX = 640, SizeY = 480 and you clicked 50%, your image will be 320 pixels wide and 240 pixels high.
WARNING: I have encountered some crashes when I changed those parameters. If you have problems too, locate the Output sub-context (usually on the left) and select the option DispView instead of DispWin. This renders the image "into" Blender instead of making a new window.
BMP- PNG- Jpeg-
AVI Raw- AVI Jpeg-