I've wanted to visit Grace Cathedral and photograph it for some time and was happy to have an hour with a sleeping baby strapped to my back to do so last week. The Cathedral itself is a master of light with her tall stained glass windows. And, the lighting artists have created a grand, yet intimate feeling within the cavernous space. A photographers dream.
Technically, architecture is a challenging subject for me. I did not add light, nor did I bring a tripod for slow shutter speeds or HDR, so instead bumped the ISO quite high in some settings (as high as 12000), but I think the 6D handled it well enough. Still there is a little noise in some of the images . Also, you'll notice some distortion with the wide lens (24mm). I didn't tinker too much in post production. Just light and color.
If you care to learn more about Grace Cathedral you can visit online.