Below you can see the default image sizes from the functions.php file.
It is worth noting that since version 2.8 of Corpus anyone can change these settings under Theme Options > Media Sizes and use the Regenerate Thumbnails plugin in order to recreate the image sizes.
This is an option that offers to any user the flexibility to fully control the image sizes. As anyone can easily understand, the sizes of your images depends on multiple factors, such as your site and elements width, sidebars and many others. It is up to you!

$size_large_landscape_wide = eut_option( ‘size_large_landscape_wide’, array( ‘width’ => ‘1170’, ‘height’ => ‘658’) );
$size_small_landscape_wide = eut_option( ‘size_small_landscape_wide’, array( ‘width’ => ‘800’, ‘height’ => ‘450’) );
$size_small_landscape = eut_option( ‘size_small_landscape’, array( ‘width’ => ‘800’, ‘height’ => ‘600’) );
$size_small_portrait = eut_option( ‘size_small_portrait’, array( ‘width’ => ‘600’, ‘height’ => ‘800’) );
$size_small_square = eut_option( ‘size_small_square’, array( ‘width’ => ‘600’, ‘height’ => ‘600’) );
$size_medium_portrait = eut_option( ‘size_medium_portrait’, array( ‘width’ => ‘560’, ‘height’ => ‘1120’) );
$size_medium_square = eut_option( ‘size_medium_square’, array( ‘width’ => ‘1120’, ‘height’ => ‘1120’) );
$size_fullscreen = eut_option( ‘size_fullscreen’, array( ‘width’ => ‘1920’, ‘height’ => ‘1920’) );

We are not going to change the default image sizes as we do not want to affect old installations. However, based on the WordPress feature to use the scrsets of your images for better performance our recommended sizes are the following.

Landscape Wide Large: 1170×658
Landscape Wide: 480×270
Landscape: 480×360
Portrait: 480×640
Square: 480×480
Portrait Large: 675×900
Square Large: 900×900
Fullscreen: 1920×1920

Remember that you always need to Regenerate Thumbnails when you change the image sizes.