[JasonB]

The forum does resize the images that you see in posts, otherwise we'd suffer from slow page loads. However, it leaves the original image intact and available by clicking on the smaller image.

I've now set the limit for jpgs at 6Mb, so you should be able to upload your photos.

To be honest though, images that big are of little use on the web, and you might actually save yourself time by converting them first using something like FastStone Photo Resizer which is free, and once you've set up your folders and sizes, it only takes a couple of clicks.