Photos add visual interest to your website. Most visitors will look at the pictures to determine the content before they read even one word. Sites like Pinterest and Flickr have made images even more important since they are increasingly easy to share.

If you have multiple images, a photo gallery presents your photos in a user friendly manner, allowing your visitor to browse through at their leisure. It's also easier on the website administrator's side, as uploading and resizing are batched.

Note: All are compatible with Joomla 1.5, 1.7, and 2.5

sigplus

Sigplus Joomla Plug-inA full featured plugin with automatic cropping and centering of thumbnails, several lightbox effects and the ability to display galleries in articles as well as modules, this popular extension. With major (and recent) props on not only the support but the documentation, it seems like sigplus is lacking in few features.

http://extensions.joomla.org/extensions/photos-a-images/photo-gallery/11426

  • Slideshow available: Yes   
  • Custom display formats: Yes       
  • Flickr compatible: No   
  • Picasa compatible: No
  • Watermark option: No
  • Lightbox: Yes
  • Cost: Free


Phoca Gallery

With lots of different display options for galleries,  Phoca Gallery is a plugin that gives flexibility in how images display within a Joomla article or module. If you are an enthusiastic Google products user, you may like how this extension allows you to not only display self hosted photo galleries and video but also display photos from Picasa and videos from Youtube.
http://extensions.joomla.org/extensions/photos-a-images/photo-gallery/3150

  • Slideshow available: Yes   
  • Custom display formats: Yes
  • Flickr compatible: No
  • Picasa compatible: Yes
  • Watermark option: Yes
  • Lightbox: Yes
  • Cost: Free


Ignite Gallery

Ignite Gallery Extension for JoomlaWant people to be able to download your images, share them on social media, or even just do something a little fancy like display with rounded corners? This gallery is for you and with some good support, this extension is not only for the more advanced discriminating user but for beginners as well.
http://extensions.joomla.org/extensions/photos-a-images/photo-gallery/5396

  • Slideshow available: Yes
  • Custom display formats: Yes
  • Flickr compatible: No
  • Picasa compatible: No
  • Watermark option: Yes
  • Lightbox: Yes
  • Cost: $40/year


JoomGallery

If you are using third party extensions like JomSocial or JComments or are looking for features like geotagging or batch upload via zip file, this gallery should be on your list to consider. When people complain there are ‘too many options,’ you know you are dealing with an extension with a lot of possibilities.
http://extensions.joomla.org/extensions/photos-a-images/photo-gallery/5481

  • Slideshow available: Yes
  • Custom display formats: Yes
  • Flickr compatible: No    
  • Picasa compatible: No
  • Watermark option: Yes
  • Lightbox: Yes
  • Cost: Free


Simple Image Gallery

If you want to display a gallery with a bit of short code very quickly, Simple Image Gallery offers a (predictably) simple solution from Joomlaworks, a well known name in the Joomla extension community. If you are looking for easy-to-implement captions or some more ‘advanced’ photo gallery features, you may want to look at other options or invest in the ‘pro’ option.
http://extensions.joomla.org/extensions/photos-a-images/photo-gallery/1468

  • Slideshow available: No (but the same company sells Front Page Slideshow)
  • Custom display formats: No (Yes with Pro)
  • Flickr compatible: No (Yes with Pro)
  • Picasa compatible: No
  • Watermark option: No
  • Lightbox: Yes
  • Cost: Free (but they have a ‘pro’ version for 14.90 Euros)

Joomla is a powerful content management system that can not only handle photo galleries but offer a variety of viewing and displaying options. What photo galleries are your favorites?