Posted: 25/05/2014 at 19:29
I use photoshop and click on the 'images' tab and scroll down to image size, then make the long side of the picture 2048. The short side will then be calculated automatically and you can then save as a separate file if you want to keep the original photo. As long as the photo doesn't exceed 3 mb they upload and can be enlarged by everyone by just left clicking on the picture when it appears on the forum page. In photoshop, when you click 'save' a dialog box pops up asking what size you want with the picture's megapixel size underneath and you can easily adjust the final pic size before saving.
Of course, you do have to have a version of photoshop to do it that way. There is a photoshop programme you can buy called photoshop elements which will work perfectly well with most PCs that is by no means as expensive as the full CS (Creative Suite) software.