I basically felt the overall impression was a bit too grey. It’s common for photographers to use grey, white or black and that is fine in itself, however you could definitely introduce a bit more contrast in the design to give it some punch without distracting from the images.
As an example, you could include sections with dark backgrounds and light text to break things up a little. Perhaps the top area below the carousel with some text and the view portfolio button could be dark with light text and a contrasting button that creates a call to action.
This creates more visual interest on the site, but also makes it easier to navigate and separates areas of key interest. A prime case for this could be the footer area, so visitors understand they are reaching the bottom of the site and that the area is separate from the main body.
Don’t be afraid to create areas with more negative space, so there is room to breath and emphasise key points. On your contact page for example, you have your title crammed up just underneath the menu and then allow very little space between that and the contact form below. This makes it harder to read and loses the emphasis on your key points. Presumably you will have clients who are art directors, so they will want to think you have some appreciation of graphic layouts.