This image is made by using Sky Free and without Compositing
Sky Free is a New Sky Generator designed for Blender Cycles, it allows you to create what Sky you want ;).
Very nice sky environment. The centres of the cirrus are I think a little crisp. You might want to see if some adjustment factor is posible for that.
Thank you for the suggestion, but now I’m working on Grass Free and haven’t time to fix it now. But don’t be afraid 
bug will be fixed and Sky Free will be improved, it is Free, updates will be Free and it will be Free forever
Truly an amazing work,and you are saying that you are making Grass generator and it’s for free truly sir you are very generous so thank you for sharing your breathtaking work and i hope that one day i will be able make great add on just like you.
Thank you so much for sharing it! I’ve just downloaded Sky free on my desktop. I’m looking forward to give it a try!!!
Nice if you can, please post some renders here because I will add them to the Trailer that will be released tomorrow 