Configuring Lightbox2 to Pop-Up Images embedded in nodes all my nodes have an image added to them (uploaded the usual way when creating new content for a content type), so when the viewer is viewing the node they can see the image inline with the text. 

It's styled to look nice, but the image is small, and sometimes a user might want to see the details of the image more clearly (however we still want to keep it small on the page by default). 

So I was thinking it would be nice for the user to be able to click the image and have the image get larger (possibly as a pop-up or overlay) on the page.

My research led me to Lightbox2 and so I installed that module. I enabled it and when into the settings in the configuration page and made sure it's loading on all pages. I also made sure the setting for 'Automatic Image Handling' > 'Image Node Settings' was set to 'Lightbox'. [I actually tried all of the options available there]. I then cleared the cache as usual.

It seemed all too simple no doubt. And indeed I went to one of my nodes and clicked on the image and nothing happened.

Can someone please help me configure Lightbox2 correctly to achieve my objective? (or perhaps give me an alternative solution).

Thanks!
Colorbox and lightbox are the famous modules for this, once you done with all configuration, go to Content type Manage display settings tab and render the image in lightbox. it will automatically shows up in the popup.
http://i.imgur.com/KA69Iqu.png