Galleries are a quick — but limited — way to display a number of photographs on a single page. In general, they should be avoided on this wiki. It is much preferred that individual pictures accompany blocks of text. However, they are acceptable in some situations, such as when displaying a series of covers, and outright forbidden in others.
For details on how to create galleries, you can read the potted Wikia help file below. Even better is the more detailed help file, which explains the finer points of wiki markup for galleries.
Things you might not have thought about
Wikia's explanation of galleries will give you an overview of the gallery process. But it won't tell you much about how the function behaves in live examples. That's why we're providing some wisdom from actual case studies.
Enough is enough
Don't go overboard with galleries. Theoretically, you can use galleries to display a very large number of pictures. This poses a problem for users who have slow connections. We're not just talking about those who use dialup. We mean almost everyone who's viewing on a smartphone, and many who are connected wirelessly.
Don't assume that everyone has a computer, or internet connection, as good as yours.
To help with this problem:
- Use .jpg files only. Other file types are either unscalable (which is vital to galleries) or far too high-quality for the purpose of galleries.
- Reduce the file-size of your gallery pictures to around or below 50kb. Certainly, don't go over 100kb with any one picture. You can reduce your filesize most easily in Photoshop by saving for web (as opposed to normally saving), and dialing down the quality to around 20. Make the filesize of every picture as small as you possibly can.
- Find a way to limit the total number of pictures in a single gallery structure. Do you really need all 200+ images of, say, Doctor Who Adventures covers on a single page? Or can you create a page for each publication year?
Watch your dimensions
Keep the dimensions of your pictures as equal as possible. The gallery function basically creates a series of thumbnails. But it's not like this kind of thumbnail:
[[file:Pic.jpg|thumb]]
No, the gallery thumbnail creates relative thumbnails. It considers all the pictures in the gallery and resizes them relative to each other, trying to put them into the specified width. (If you don't specify a width, it defaults to 200px.)
This can produce some highly unexpected results if you're trying to create a gallery of pictures with radically different dimensions.
Technically, there's always some level of distortion in a gallery, if the pics don't have the exact same dimension. But it is considerably less obvious if the files are all of the same dimensions.
Putting a lot of pictures of widely divergent dimensions in the same gallery often results in "warping" or "stretching" of some of the images.
To help with this problem:
- Try to use images that are all of the same dimensions. If you're displaying a series of magazine covers, for instance, it's a good idea to crop all of them to precisely the same dimensions. That way, they'll all be perfectly scaled down.
- If you must use a mixture of widescreen, 4:3, and extremely skinny images, don't put them all into the same gallery structure. Find a way to break up the galleries on the same page, so that the gallery command is not having to work so hard.
Rules of use
There are a few absolute rules which should be observed when using galleries. Failure to observe these rules could end in blocking:
- Never use a gallery for a single picture. Single pictures should be placed on pages using the syntax:
[[file:PicName.extension]]
as described at Help:Files. There is simply no advantage to using the gallery structure for a single picture; the wikitext for file display is invariably superior for the task. - Always hide the galleryadd button. All galleries must begin with a command that looks like this:
<gallery hideaddbutton="true">
- Never use galleries on in-universe pages.
- Use caution with galleries on story pages. Generally, they should be used only when displaying a series of alternate covers. There is no other reasonable usage for galleries. No story page should have a gallery of images from that story.