Thread:Project:Support desk/How to open a image in a new page?

I know $wgExternalLinkTarget = '_blank'; can make a external link open in a new page.

but how to make image open in a new page?

For example: http://commons.wikimedia.org/wiki/File:Orchid_FL_PI_NWR_view_area_Centennial_Trail_bdwk10.jpg

I want to click the picture in this page and let wiki show the full size image in a new window, instead of in same window.