What is creating smudging in my render? The below given image is rendered with 1000 samples with appropriate light settings but the final rendered image is coming as smudged.
Is there any solution to fix this?



EDIT : please find the link for .blend file below.

https://drive.google.com/file/d/0B5pwuQ_y8BGXaURWMWxOLUVlWWc/view?usp=sharing
When dealing with glass you need the object to have some thickness.
To illustrate the issue with two identical glasses:



The glass on the right has only a subsurf modifier, you can clearly see a lot of artifacts as white and black bands. The one on the left has a Solidify modifier before the subsurf. The glass looks much cleaner and realistic, and you don't need that many samples (This image was rendered with only 100 samples)