PannaDraws

I usually keep the width of my sites between 900 and 1000 px. That should be fine... However, I thought about it and the purpose of your site can also define what size you need. I mean, this is a photo portfolio, and photos should be viewed in high resolution (higher than one that fits into a phone browser), otherwise they don't look good. I could imagine something that resizes the pictures according to the browser they appear in.

The first thing to notice was the same for me, the site doesn't fit in screens with smaller resolution. Loading speed was fine, and I like the way the credits are added to each picture.

You may also try to edit your background picture in Photoshop or some picture editing program... Unfortunately not all CSS3 features work perfectly in all browsers.
You can also try to separate the grayish background and the glow, make a png file with transparent background from the latter. Then you can set the gray as the background image of the body and to repeat, and create one container div (with all the other divs inside it), which will have the glow as its background, without repeating.
I hope this was helpful somehow