I have similar problem and I don't know how to fix it.
Maybe somebody know what can I do.
I have a tiled game field it can has different size (15x9 and 20x12 for ex.) and all time it should fit in screen.
For camera I am using modernisation of this script https://github.com/britzl/publicexamples/blob/master/examples/fixed_aspect_ratio/fixed_aspect_ratio.render_script , just replace original_width and original_height with width and height of my current level.
Virtual resolution of the game is 2048x1536 (and sprites resolution made for this screen)
In most case my game field downscaled, and image becoming too blured.
This is original size of game field with linear filter in game.project
This is 0.5 scale image (zoom_factor is 0.5) and linear filtering (too blured)
This is 0.5 scale image (zoom_factor is 0.5) and nearest filtering. Much better, but when I try other zoom_factor (not 0.5) it's fully pixilated. but I need other zoom factor because I have different level size and many screen resolutions.
and for example file was made using photoshop from original sources scale = 1
and the same file 0.5 scale
I am fully read all forum topics and documentation about rendering, but absolutely have no ideas how to fix my issue.
Maybe somebody know some solution to make image less blurry.