Size of image for article Schema

[AL123al]

Hi, I implemented schema markup for an article and all tested fine and I can see it being fired in preview mode of Google Tag Manager.

But when I run the URL which has it applied through Google Structured Testing tool it is not appearing. I have now read that the image needs to be a certain size.

For AMP articles this appears to be 12oo pixels wide http://www.thesempost.com/google-changes-image-size-requirements-amp-articles/

But what about non-AMP articles? Does it need to be that big too?

[AL123al]

I've got the answer myself but didn't know how to delete my question - sorry

https://developers.google.com/search/docs/data-types/article#non-amp