I go to the "Settings" page and click on the "Media" tab.
The default setting for the "Medium" width/height is 300 x 300, and the default setting for the "Maximum" is 500 x 500.
I changed the "Maximum" values to 450 x 450.
Then I went to my blog and clicked on the "Add an Image" icon.
I select an image that is 722 x 410 in size to upload.
After the upload the following sizes are displayed by the upload manager:
Medium: 300 x 170 - this makes sense
Large: 500 x 283 - Why is this not 450 x 256, since I specified the maximum width to be 450 above?
Full Size: 500 x 283 - Why is this not 722 x 410?
When the image is used in the blog I looked at the height/weight parameters in the HTML and they also use 500 x 283 so it appears I don't understand the concept of using the "Settings / Media" page to control image size. What am I missing?