Step 4: Apply The Gaussian Blur Filter To The Merged Layer

To create our high contrast glow effect, we need to blur out our merged layer. To do that, with the "Glow" layer selected in the Layers palette (I'll assume from here on that you're renaming your layers), go up to the Filter menu at the top of the screen, choose Blur, and then choose Gaussian Blur, which is by far the most commonly used filter for blurring an image in Photoshop:

When the Gaussian Blur dialog box appears, drag the Radius slider at the bottom of the dialog box towards the right until your Radius value is around 6 pixels. I'm working with a low resolution image for this tutorial, but if you're using a high resolution image, you'll want to try a slightly higher setting. You want to apply just enough blur so that you remove most of the detail from the image without going so far that you can't make anything out at all:

Click OK when you're done to exit out of the dialog box. Here's my image after applying the blur to the merged layer. Notice how I've blurred it without going beyond the point where it would be impossible to figure out what's in the photo:

Step 5: Change The Blend Mode Of The Blurred Layer To "Overlay"

Now that we've blurred out our merged layer, go up to the Blend Mode option in the top left corner of the Layers palette. It doesn't actually say "Blend Mode" anywhere, so just look for the selection box that is currently set to "Normal". Click on the down-pointing arrow to bring up a list of available blend modes and select Overlay from the list:

If we look at our image in the document window, we can see that it now has a soft, high contrast glow to it, which is a great effect to use on a photo even if you're not trying to make it appear older:

Step 6: Lower The Opacity Of The "Glow" Layer

If you find, and you most likely will, that your glow effect appears too intense, you can adjust it by simply lowering the opacity of the "Glow" layer. The Opacity option is directly across from the Blend Mode option at the top of the Layers palette. I'm going to lower mine all the way down to about 70%:

If we look at my image again, the glow effect isn't quite as intense as it was before:

Up next, we're going to darken the edges of the photo!