@Diadalos:
There is really no "preferred" size...you can load up whatever Rendo allows. I was merely pointing out that dial-up folks will likely skip waiting for a 500kb image to load...so, you lost a viewer.  As for pixel dimensions...same thing....load right up to the Rendo limits if you so desire.  But bear in mind that unless people have the resize option checked here at Rendo, they will have to scroll to see the whole image.  If you have to scroll, you generally lose the impact of the image.

Another point to consider here....the larger your image size....the more value it will have to rippers that may want to steal your image. Again, the choice is yours......

@MrsRatbag;

My comments apply to both galleries and forum uploads.

In youth, we learn....with age, we understand.