Some modern Japanese ships seem appropriate for this. The file size on the original image is 5MB as can be seen from the next image – which is copied straight from the WordPress media library.
The size of the original image is 3120 x 3120 pixels and I am sure the blue background is increasing the file size a little.
I have a second image now which I will select Edit Image on and we can have a look at how you cut back the image size. Because I took two images we can also see how the images look when clicked on.
You can see on these dialog boxes that you also crop the image by aspect ration or by selection. Lastly, you can restore the original image size but I think that only works if you are still in this part of the editor. Once you go back there is no turning back.
When you have the desired size, and I would suggest playing around with it until you get the resolution you are after, press <BACK> at the bottom of the screen to bring you back to the Media Library.
The reason I was working with two nearly identical files is so that you can compare the resolution both before and after resizing.
The photo below is the 989KB one with lower resolution than the original.
However that will likely slow your blog down a little.
So, a lesson in resolution and space.
Next will be some book reviews followed by some new toys to look at.