SharpDX HLSL Shader Radial Blur

Hello!

I am using SharpDX.

I have a task: to implement a shader with the Radial Blur effect. The shader works well, but there are some minor issues.

The shader is applied to the whole scene, thereby the edges of the scene are blurry.

In the first screenshot, the result is how it works now. In the second screenshot, I would like to see it.

Tell me, which way is it worth looking to achieve the desired result?

Thank you all in advance!

Shader Source Code:

#define BLUR_SAMPLES_COUNT 70

struct PostProcess_VS_OUT
{
    float4 pos : SV_POSITION;
    float2 textCoord : TEXCOORD0;
};

Texture2D gTexture;

SamplerState …