@chyron: 21 is way too low, you need at least 18 for any decent result.
@lpd: When putting the pics on here, you can set the width to 720 and leave the height empty - that way it will automaically adjust the aspect ratio and make the pics fit the forum layout.
You can also edit your previous post and do this retroactively by clicking first on the picture and then on the little green tree icon.