check colorgrading shader. I downsample the whole image into one pixel(or tried to), then upsampled it back. The trick is you have to do it in separate passes. (But I multiplied with wrong number in the end, I forgot that. You do it with the same number.)
tex2D(s0, tex*16); //downscale
tex2D(s1, tex/16); //upscale
But I think there are some other methods bicubic, bilinear... But I don't think Crysis downsamples for DoF, for DoF you need high quality.
@Scanti
We began to pass alpha between passes for MGE some time ago for the very same reasons. And for vertex shaders, I am OK with that. It won't change things drastically. We can add that flag very easily.
@Vargr,
See it is working. The shader is the same, suggesting the problem is with plugin support and your save game. Your save game is holding old values for the godrays shader, which are wrong now for the new shader. I'm pretty sure this is the reason. If you remove the plugin support and start a new game, (use shaderlist.txt), it will work. I'm sure of it.