Hi,

I first need to confirm what effect “Preload” has on images. My assumption is that it will ensure the image is sent to the client during the course launch / initialisation stage and will eliminate any delay (e.g. pop-in) when the image it called. The reason for my uncertainty is that confidently confirming this behaviour is quite tricky.

If I am correct about this, would it please be possible for the image Preload property to be set to True by default? I cannot think of any scenario where I would prefer to see a delay when the image loads.

Many thanks in advance.

I second this. I can only think of a couple of instances where it would be nice to have an image not preload. It would make more sense to turn it off if it isn't needed.

Hi,
Unfortunately, preload is a tricky beast, and it depends to some extent on the resource usage of the browser, as well. We could make it so that every image is set to preload (or you could), but there are some issues:

1. it would dramatically increase the initial load time of the lesson,
2. browser cache can discard large images or numerous files, which means that image data needs to be loaded a second time when a particular page loads (meaning you waited initially for nothing),
3. even if the data is loaded, it can sometimes take the browser some time to render the image, depending on its size - so pop in is not guaranteed to be eliminated.

When there are pages with lots of images, and most of the images are not starting visible (such as a software scenario, or a flipbook), the later images are being loaded while the page is active. So ideally, only a few images that are initially visible when the page loads need to be set to preload.

Overall, think of the preload feature as a way of telling the browser to "prioritize" certain images. If you prioritize everything, then nothing is prioritized. We'll see about adding a lesson-wide setting for preloading all images, but it may just result in more waiting for the same outcome. The BIGGEST impact you can have on loading / rendering is to make sure that the images are as a small / compressed as possible (and we do have a setting in the Edit > Lesson Settings to allow / disallow compressing images).

I hope that clears things up a little!