The file size limit is 1MB, but the the image dimension limit has been set to 6000px x 6000px (subject to change). Images larger than 1024px will automatically be shown at 1024px, but clicking on them will take you to the original size and hovering the mouse over the resized version will show a magnified view of the detail (ranging from 100% to even higher depending on the size of the original). To see how it works, look at my test image here, and try the mouse hover, then click on it. Of course, a 4000 x 3000 image compressed to 1MB is going to have a lot of compression artifacts and take a hit on overall image quality/detail, as you can see in the example I posted, so everyone will have to pick their own compromise between size and quality. I can't increase file size limit at this time due to bandwidth limits.