The 10-22mm is vital for street photography, it's the killer architecture lens and absolutely essential if you want to take photos of big things like skyscrapers and palaces, bridges, landmarks and other such things.
Great for landscape too, it's range covers most of what you will want landscape shots, though you will probably tend to use closer to 22mm most of the time than 10mm. But the flexibility to go to 10mm when you need it for a landscape shot is important.
15-85mm is probably the most useful lens for a street photographer, it'll do almost everything great except for architecture where you'll need to have ready the 10-22m. The 15-85mm is ideal for capturing the streetscape, the 10-22mm will distort the street too much and make any cars or people near the corner of the frame look very odd. 15-85 will also do compression shots through busy groups of pedestrians and traffic. And let you capture small objects of interest and people.
I do a lot of street photography, and I find the 10-22mm and 15-85mm together as pair do everything I need, with high image quality too.
Earwax69 wrote in post #14839745
How the 15-85mm behave in low light? Is it hunting a lot? I dont care so much about blurry pics but I hate when the lens cannot find the focus.
It focuses good in low light and it has a good image stabiliser, but it's still a pretty slow lens and you're gonna need a high ISO. At 50mm for example it's limited to f/5. Consider the 17-55mm if you want low light, f/2.8. Similarly high quality optics though you lose out big on range, telescopic up to 85mm is important for street photography if you want to for example zoom in on an interesting individual.