The core functionality of Imagehandler is that it creates scaled versions of the images. So, what you do is upload a large image ( in size not as a _LRG file) . What Zen would do then is server that image whenever requested. Which results in the big image being served even when a small image is needed. Which burns bandwidth.

So, what image handler does is create scaled versions of the images. So when the small version of image.jpg is required it creates it. Then it uses that small scaled image whenever required. So, it means that sites are much much faster and bandwidth is not burnt.

Most developers will put image handler on the site as the very first module they use. And most people should too, to be honest. There is a bit of a logic which says that this functionality should be rolled into the core of Zen ( like prestacart, magento, cs cart, open cart, wordpress ) but I am not going to get involved in that. So, alot of people would say that Zen is not complete without IH.

So, that is kind of why I think that you have to support it to make this a really good module as opposed to a functional one.

The thing about IH is that it creates the images when they are needed. Which can cause issues with javascript because the 'medium' version of a file may not actually exist until it is required. Javascript does not send a request the same way as html does so the image may not be created. Which means that the zoom just won't work.

The usual way to bypass that is to pre-load the images low down on the page. that way they are created before the zoom needs them. but as you know that in itself creates bandwidth issues.

IH has some other features - some of which are useful and some of which are not all that useful and the people managing it would probably ditch if they could.
  • It creates lovely lovely hover effects. Most developers hate these but the public seem to like them
  • It adds a better interface for uploading additional images

There are probably a few others that I am over-looking.

But the core functionality is scaling images to the right size before they are served.

I have gone on record as saying that I am not a huge fan of IH. ( Just because it is cumbersome for what it does ) I use my home grown alternative. But some kind of server side image management is pretty much a necessity for most users.