wierd grainy images

[the_seraphim]

ok so here is a render of my scene (only a basic scene) its all grainy and i dont know why.

ive included the tgd file so you can try and recreate it if you dont recognise the problem

[Njen]

Most probably your atmosphere quality is too low.

[Henry Blewer]

Try increasing the atmosphere samples to 32. This is a good start, though the green may be too green. I would add a power fractal to the color input. Make the power fractals color an olive drabbish color. It should mix well and allow the bright green to look nice.