GIF-quality by flattening of layers

[MatthiasD]

When I make an image with (2) layers and I save it in PNG, the image has the quality of a GIF-image (look at the sky on the image). Does someone know what there is wrong?

 

[BoltBait]

In the "save as" dialog box, be sure to select "Auto" or the appropriate bit depth you want.

[MatthiasD]

Thanks! It helps!