Indoor photo lens suggestion needed

A client for whom I shoot HS football actions shots has made a special request that, while on campus this Saturday to shoot a JV game, I stop by a new building they are opening to shoot some pictures of the outside of the building and selected portions of the inside, for their use in their yearbook and newsletter.

I'm a total NEWB to shooting inside (other than holiday snaps). I'll shoot with my Digital Rebel XT and 580EX flash with a Ominbonce, I presume, but what lens would be best? I have the kit lens (18-55) and a 28-135 IS Canon as well as a Canon 50mm f1.8 II.

Any suggestions? I can rent a lens for the weekend if needed. Also, should I shoot in Av mode to control the DOF?

Any help would be appreciated.

Thanks,

Dennis

Bear in mind that lighting could be much more of an issue than a lens. The lighting in a building is often geared towards providing light for the people in the building and not for lighting the building itself. It might be worth while to check out the place before going for the shoot. On-camera flash is very probably NOT the way to go. There's no way to get evenly distributed light from a single flash unit. An on-camera flash probably doesn't have anywhere near the total power needed, either.

A good solid tripod will be a must.

You probably want to shoot in manual mode, selecting both the shutter speed and aperture for the best results. I would suggest stopping the lens way down (but not necessarily the minimum aperture) to gain the best possible depth of field. Use lower ISO settings.

If you need a long exposure time, that's what the tripod is for. If you're shooting a static building (with no people or other things moving in it), you could easily do a two-second shot for example. Another thing that will be critical is white balance.

Shoot in RAW mode. That way you can easily correct the white balance in post processing if needed (that is, if you didn't get it right in the camera).

Hey, Skip. Great advice. In fact, I have a 580EX and a 420EX that I might be able to employ in a Slave/Master mode.

I don't think I'm going to be able to scope the place out beforehand, nor do I think I'm going to have too much time to shoot. Kind of a Shoot and Run engagement since it is an afterthought.."Hey, while you're out here shooting the football game, could you take some pictures of our nice new building?".

There will be a guy from the school there to let me in the building. Maybe I can get him to hold the slave flash.

I just had a flash thought (pun intended).....

If you can put the camera on a tripod and do very long exposure, you might be able to walk around the space and pop a handheld flash a number of times to "paint" light into the space.

Mixing flash with existing light that is not daylight is a bad idea. You will end up with very different color balances in different parts of the picture. Unless you have the time and lighting equipment which roughly matches the color of the ambient light then it would be better to use a tripod and shoot with available light. You can balance out contrast using blended exposure if light is to uneven. As Skip mentioned you can paint with light with a portable flash. I use a color conversion filter over the flash if the main lighting is not daylight, a Rosco CTO filter for tungsten or a Rosco Plus Green for flourescent. If your Photoshop skills are good you can knock yourself out doing blended exposures, masks and other corrections.