Originally posted by Pentaxoid How does this lens compare to the 14mm 2.8? Is f/4.0 enough for indoor / low-light shots?
Many of them, sure. It's not like you're taking portraits at 15mm - it's more about things that don't move, and you don't need a fast shutter speed to combat camera shake at 15mm. Crowd shots will often have a little motion blur in some of the figures; many of the people will be rendered so small because of the wide field of view that it just doesn't matter - you weren't going to see much facial detail anyhow.
I've posted these elsewhere I'm sure, but here are some basic indoor low light shots taken at ISO 1600, f/4, and shutter speeds of around 1/15", 1/10", and 1/30", respectively. You could of course get faster shutter speeds at higher ISO.
Those are pretty low light levels; many indoor situations are a lot brighter, as in this one, taken at ISO 800 and 1/60":