Caving by lamplight: what setup?

[John Tillinghast]

In a few days I'll be going on the Violet City tour at Mammoth Cave. It's all done by lamplight -- no flashlights or flashes allowed -- so it feels more like the early explorers in the 1800s.

But I still want to get some nice pictures. Remember: NO FLASH. Lamplight only. I have two lenses to choose from, an f/1.7 normal (40mm equivalent) and an f/3.5+ prime (28-84 equivalent). (The camera is a Panasonic G1 in micro four thirds format, so the prime lens is actually 20mm and the zoom is 14-42. This also means that 1600 ISO isn't quite as good as on an APS-C.)

Is there any chance that I will get *anything* from the zoom? I'd like to have that flexibility, especially on the wide, but I'm worried that I'll need 2-second exposures.

[LukeM]

Assuming no tripod or monopod is allowed I would guess that you will need all the aperture you can get to get a decent picture by lamplight. Not sure how bright these lamps are that they're using, but if they're similar to carbide in intensity it will be hard to take a sharp handheld photo no matter what.

20mm is a good all around wide. I'd mostly worry about not being able to get good close ups myself.

[John Tillinghast]

In micro four thirds format 20mm is more normal than wide. About a 40mm perspective in the film sense.

[LukeM]

Ah, I read that backwards, thinking that you had effectively a 20mm lens. In that case, I might pick the zoom since the prime may be a little tight. It is a tough choice though. No chance of a small monopod or tripod then?