Lens for baby portraits- Questions

I'm finding myself about ready to upgrade my 28-135mm IS kit. I am pregnant with my second baby and need to find a lens that performs better indoors under natural light than my 28-135, because I'd love to be able to take better pictures of my kids. This is a tradition in my family that when a baby is coming the husbands gets the mom a really nice gift. My husband asked me what I want and I said a lens. Canon, Sigma, Tamron, brand isn't as important to me as finding a good lens in my price range. What fast lenses in the ~$600 range do you guys suggest for babies and kids and why?

On crop, sigma 30mm f1.4 art, sigma/canon 50mm f1.4.

Canon 85 1.8 or 50 1.4

maximus_73 wrote in post #16232356
Canon 85 1.8 or 50 1.4

Normally I would second these but seeing that the op doesn't have anything wider than 28mm on crop, I am thinking the Sigma 17-50 or if she can stretch the budget another $200, then the Sigma 18-35.

I would use the Canon 35F2 for this. You can try a 50, but it may be too narrow a view in tight spaces.
If you can swing some extra dough, I would go for the more expensive 35F2 IS. The Canons give you good performance at F2 and fast and accurate AF. If you get the less expensive Canon, get a Canon hood and keep it on at all times for protection of the f don't lens assembly.
You don't need wider than F2 for this purpose. If you decide to get a Sigma, I recommend getting one early enough so you can check it out in advance of the birth. Some people have had to send them in for AF problems. Babies only arrive once.

SkyBaby wrote in post #16232302
I'm finding myself about ready to upgrade my 28-135mm IS kit. I am pregnant with my second baby and need to find a lens that performs better indoors under natural light than my 28-135, because I'd love to be able to take better pictures of my kids. This is a tradition in my family that when a baby is coming the husbands gets the mom a really nice gift. My husband asked me what I want and I said a lens. Canon, Sigma, Tamron, brand isn't as important to me as finding a good lens in my price range. What fast lenses in the ~$600 range do you guys suggest for babies and kids and why?

Sigma 30mm 1.4 and either 50mm 1.8 or 1.4

I think a prime lens on your 50d somewhere around 30-50mm. My daughter is 11 months and I'm saving for the Sigma 35mm 1.4. I use my 85mm 1.8 outside but inside it is a little long. I bought a cheap flash to bounce off the ceiling for my Tamron 28-75 because even at 2.8 it is not fast enough sometimes.

50-60mm prime is ideal for baby portraits. 30 or 35mm forces you to get in too close and you get distorted heads. 85mm can work, too, but you'll run into distance issues indoors due to the long focal length and long minimum focusing distance, especially as the kid turns into a toddler

If you feel you'd like something wider than your 28-135mm for all around use, then I'd get a 17-50mm f2.8 from Tamron or Sigma. You can use the 50mm f2.8 end for portraiture and the wider end for general use.

35mm f2 and 50mm f1.8 are good choices for crop body (50D).
Had them both and are good performers indoors

30/35ish prime lens & a 430EX

Wow thank you so much for all the replies, folks! Very helpful. I have shot with a nifty fifty, the traveling nifty on this forum actually, and that was nice. Definitely on the list. The head distortion at focal lengths wider than 50mm comment Taylor posted explains the distortion comments I got when I posted shots of my then newborn daughter. Looking at the exif of those again, I was shooting at 28mm so I could shoot wide open. Ok, so I guess the Sigma 30mm 1.4 might be scratched off the list for that reason, even if it does do very well indoors. I do like the idea of the 50mm 1.4 or 1.8. That is low enough that I can afford my first flash with the extra. Just thinking out loud here really. I have some time to make up my mind, considering this baby isn't due until Feb 5.

So you are happy with 28mm as your widest focal length?

54mm on 1.3x crop

The big head problem.

30mm f1.4 on 1.3x crop (so wider than when used on 1.6x crop)

I would agree with the suggestions of a 30/1.4 or 85/1.x if it weren't that until now the OP seems to have only used zoom lenses.
Shooting a zoom is quite different from using primes. When you can move around freely a prime can be the most suited tool because of the freedom in exposure it provides.
Unless you have the time to get used to that I would not advise a prime but a fast, image stabilized standard zoom 1n the 17-5x range.