Pixelated postprocess Fish-eye lens effect

Stu2Prof

Hi guys I am trying to create a fish eye lens effect with a strong blur but am having some problems with my end result. The necessary distortion is happening but it is very pixelated. At first I was using a 512 texture for the fish eye distortion and thought that might be causing it but when I raised the resolution up to 2k and blurred it in photoshop the problem still persisted. My next guess is that the camera feed being distorted has a fixed resolution which is why Im seeing pixels. Is there a way to increase the resolution of the camera/effect? Or is something else causing the problem?

Vailias

Are you doing this as a post process effect? 
Why not just change the FOV of the camera then do a blur and vignette as post process?

Stu2Prof

I would like to get the warped distortion which wouldnt be convincing using just a vignette.

spectronaut

Try using a lower res texture.  Upsampling might blur and reduce the pixely stair stepping you might see. 
I've done this in the past, and lower res texture gave that fisheye but what we ended up doing was a Bezier math based approach.

Stu2Prof

Hey Spectronaut Could you tell me a little more about your "bezier math based approach"? 
since this post I have been trying the 2 methods listed out on the page here  but I'm either getting bad aliasing or it is coming out too small on the camera. Is your approach different to what is listed on that tutorial page?