24-70mm or 70-200

[mgilmore18]

If you are using a crop sensor camera there may be other options

Yes, using crop. I haven't purchased a new body since I got my camera a few years ago. (Nikon d3200)

 

[jaomul]

If you are using a crop the 24-70mm option is not the best as it leaves you very wide at the narrow end. \a better alternative may be something like the nikon 17-55 f2.8 or indeed the sigma 17-50mm f2.8 os. 70-200mm lenses are generally lusted after, but the focal length may not be quite as useful on a crop sensor as on a ff, especially for event photos where one may be limited for space.

I'd imagine a lot of the previous answers assumed you were using a fullframe camera. If you asked the same question and defined crop I think you may get different answers

 

[SquarePeg]

I highly recommend the Sigma 17-70 f/2.8-4. Very versatile.

 

[mgilmore18]

If you are using a crop the 24-70mm option is not the best as it leaves you very wide at the narrow end. \a better alternative may be something like the nikon 17-55 f2.8 or indeed the sigma 17-50mm f2.8 os. 70-200mm lenses are generally lusted after, but the focal length may not be quite as useful on a crop sensor as on a ff, especially for event photos where one may be limited for space.

I'd imagine a lot of the previous answers assumed you were using a fullframe camera. If you asked the same question and defined crop I think you may get different answers

What about the 35mm 1.4?

 

[jaomul]

If you are looking for a set of good portrait gear for a crop sensor you basically need the same as the equivilant on fullframe. The 35 f1.4 would work well, but the 35mm f1.8 dx would work 95% as well at a fraction of the price.

An example of a good portrait kit for crop would be the 17-50 sigma f2.8 I suggested, the 35mm d1.8 dx, along with maybe the tamron 60mm f2 macro. Macro's are handy for little hand and feet shots and small details, but this tamron has a reputation for being a very good portriat lens also, and it gives you a small bit of telephoto reach to complement the 35mm, it also fills the gap between the 17-50/55 amd the 70-200 should you decide to go that route. A few reflectors and a ttl flash to go with that and you could cover quite a lot

More experienced photographers will likely chime in to add to this, possibly giving better examples etc, but I'd be happy to do a newborn shoot with the above (I'd imagine the 35mm is not really critical either, the 17-50 can cover it adequately, and in reality if you have the light shooting at less than f2.8 for portraits is not to common)