Poster command is not working with water reflections

I’ve been recently working on a very complex pose in which the water reflection is crucial to the pose. However, whenever I use a poster command that is higher than 1 or 2 the reflection gets all fucked up.
Does anybody know as how I can fix with console commands or atleast circunvent this issue? I would really want to take a really high resolution version of my pose so I can edit.
Or could anyone list any other method of taking pictures at really high-quality and high-resolution other than downsampling (since it does not work with my monitor)

Here is a image showing the problem with my reflections (poster 2

(It’s size has been reduced for convenience)

Post your graphical options for GMod.

currently not using any console related commands or configs