Putting pictures on website using lightbox
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I'm in the process of making a website for a school group and the website will have a lot of pictures of its activities. I'm using lightbox so the pictures will display as a slideshow and I changed the dimension of the pictures so the "current" picture on slideshow isn't as big as the original. I still find about 5 seconds delay from opening the picture or going to the next picture. I'm wondering if there's a way to achieve a faster load time or even another method I didn't consider.

I'm using xhtml, css, and php for my site.