AP - Gaussian Blur live filter vs filter

[EdD]

I've come across something that seems odd to me. I'm hoping there's a simple reason for it that someone could explain.

 

When I apply Gaussian Blur as a live filter layer it creates an apparently transparent area along the edges of the image. When I do the same with a Gaussian Blur filter it doesn't happen. As a fan of non-destructive adjustments I typically only use live filters.

 

To clarify what I'm seeing here are 2 screen captures. The first shows the live filter and the second a filter. Each one has Gaussian Blur set to the extreme to illustrate what's happening. Anybody know why this happens and how to avoid the effect with a live filter?

 

 

 

 

Thanks.

[R C-R]

Click "Preserve Alpha" in the Live filter & it should extend to the edges, just like the destructive filter version.

[EdD]

Thanks R C-R that works. Can you explain what is happening there, as in what is preserve alpha doing that toggles the effect? I don't understand what the alpha is for in this situation.

[R C-R]

7 hours ago, EdD said:

Can you explain what is happening there, as in what is preserve alpha doing that toggles the effect? I don't understand what the alpha is for in this situation.

See this post in another topic for my thoughts on that, but I am not at all sure it is really much of an explanation.

[John Rostron]

12 hours ago, R C-R said:

See this post in another topic for my thoughts on that, but I am not at all sure it is really much of an explanation.

I looked at your post (a response to a problem I had). I had not understood it then, but in the context of EdD's question, I now find it does make sense.