How can I recreate the shadows and blur effect using Gimp?

Question

So I'm fairly new when it comes to working with images and creating different effects.

But can anyone explain what effect is being applied to the conference logos in the following link?

The middle of the logo is brighter and as you work your way outward, it gets darker.

Are there any good tutorials to reference in to recreate this effect? I'll be mainly using Gimp for this.

Answer 1

This looks like there are two layers on top of the original logo:

1. Light grey to black radial gradient - in Multiply mode, and
2. The original logo duplicated and blurred - in Lighten mode - probably with opacity around 50%

Answer 2

I kinda agree with the answer by Const, but you can also do this by:

1. Adding a vignette to the logo—you can do this by going to Filters > Lights and Shadows > Vignette
2. Add a Gaussian Blur, which is also can be found via Filters > Blur > Gaussian Blur

Here, you can mess around with the settings until it matches perfectly with your desired images. Hope this answer helps :D