Change size of thumbnails in media library pop-ups?

Hi all,

I’m currently developing a site that uses the Advanced Custom Fields plug-in to allow users to upload and select images to appear in various parts of the theme templates.

So far, so good. Functionality works just as I’s like except for the fact that the deafult thumbnails WordPress uses in the admin media library pop-up windows are very small and therefore make it difficult for a user to accurately select the image they wish to use.

Does anyone know if it is possible to increase the size of these thumbnails?

I am not talking about the image thumbnails themselves; I know this can be done with the regenerate thumbnails plug-in and all my images are set to the sizes I wish for them to appear in the templates. The thumbnails I am discussing in particular are the thumbnails used by the WordPress admin system in the ‘set featured image’ pop-up box.

Any help would be greatly appreciated.

Adam.