A problem with second camera culling mask (Semi- Transparent)

Hi, I'm trying to get a pixelated effect on a specific object in my scene by using a second camera, culling mask and raw image with low resolution. However every time I press play, in the game view window it shows the pixelated object as a semi- transparent object, and that's no what I want. Can anybody help me with this one?

A video: https://youtu.be/7fwnofz2Uho