When you upload an image you are given three versions that you can insert into the post:
- Thumbnail (150 x 150 pixels)
- Medium (300 x 300 pixels)
- Full Size
You are able to change the size of thumbnail and medium sized images under Settings > Miscellaneous.
When you insert an image into a post using the “full size” option, the image is automatically resized to a maximum width of 500 pixels. This is to prevent problems of wide images in blog posts caused when people post photos straight from digital cameras.
How wide an image can be depends on your blog theme. Some themes 500 pixels is too wide and the image will flow into your sidebar area. While other themes can cope with images wider than 500.
