The art of photography is one of the most communicative mediums of the modern society and it has many uses for business, science and art. Over the last years the development of digital photography has allowed a large use of photos also in Web Design.
The last trends in the art of making good websites show a wide use of large photos to improve the harmony of the page.
Some SEO experts can tell you that large websites will harm you SERP rank and Google will block you, but I do not agree with that. Large not optimized image definitely will slow down your website speed and you can loose your visitors, but nowadays are so many ways how to make even large images smaller in size that only that isnt fact why you must no to use it in your design. Large images will make more focus on your website idea, images talk more that text, people understand images much better that text, therefore I encourage you to use large photos in web design.