Need a fast under $400

Ok, I got a 20D (1.6x Crop) about 6 months ago with the kit lens. The lens has served me well, but it is time for a new lens, given the amount of time and effort I am spending with my photography. The problem, of course, is budget. At this point I have at most $400 to spend. My main requirements are that it is a fast lens, that I can get some good background blur, and that it has as much optical quality for the buck (low distortion sharpness etc). Of course we'd all like our cake and to be able to eat it too, wouldn't we? Another factor may be that a baby is on the way, and I imagine I'll be taking a lot of pictures of him/her..

I dislike flash, and like to shoot in low light. I would say that I mostly shoot in the 20-55mm range (but of course I am limited to that due to my kit lens). These are what I am considering. Please chime in if you have any thoughts on the matter (all prices from B&H):
1) Canon 28mm f/1.8, $400
2) Canon 35mm f/2.0, $230
3) Canon 50mm f/1.4, $320
4) Tamron 28-75 fixed f/2.8, $360

Am I better off at this point sacrificing the flexibility of a zoom and getting a good quality prime, or does the Tamron compare in terms of optics to the 35, or 50mm Canon primes?

A lot of people like the Tamron. Get it and spend $80 on the 50mm 1.8. A little over your budget but two great lenses.

Yeah. I have looked at the 1.8 but am suspicious of its build quality. I like the Tamron, though it is hard to really put a lens through its paces in the store. It feels like a very solid lens though. Your suggestion is definitely worthwhile, I guess I would rather spend more money on one quality lens than get two that I will be disappointed with. Just a thought...

Go for the 50 f1.4. It is a great portrait lens, so you will be able to take nice pics of your child. It is very good in low light.
Good build quality, very sharp when stopped at f2.
Best bang for the bucks

Another vote for the 50/1.4.
I have the 50/1.4, the 28-75/2.8 and the Sigma 30/1.4 (sold my 28/1.8 ).

The Tamron 28-75/2.8 comes nowhere near the 50/1.4 as far as speed and image quality are concerned. OK, my Tamron is not the sharpest copy, but it's tack sharp (when viewed at 100% crops without post processing) at f/4.0. The 50/1.4 delivers the same sharpness at f/2.5.

Another lens to look at might be the Sigma 30/1.4 EX, but it might be more than the budget allows.
And ... of course ... the 85/1.8, but that might be a bit long.

As to the impact of the 2 focal lengths (28/50), take a look at this thread, I've posted sample images.
The 50 is much more powerful for portraits, IMO.
The 28 is pretty usable for 'environmental portraits', but you don't get the same bokeh because of the shorter focal length.

Best regards,
Andy

50mm f/1.4

again, 50 1.4. I'd love to have that lens again. It was just awesome. Sometimes I would use JUST that lens for long periods.

How fast do you want it? If 2.8 is ok for you, you'd probably be better off with the tamron.

If you want something faster, you'd be able to pick up 50/1.8 and 35/2 - and have "most of it" covered with fast lenses.

I have 50/1.8 If I had your budget I'd get 35/2 and 28/2.8 Those three small primes give you great flexibility in low light.

The wide angle is still covered with the kit lens at f/3.5 The only alternative to that is 17/3.5 tokina, but I don't know if the lack of barrel distortion is worth it.

Knowing what I know now, my first lens would be the 50mm 1.4 or the 85mm 1.8. Both are excellent lenses. Great for no flash / low light photography. The 50mm 1.4 would probably serve you better. My 50mm has not left my camera since it arrived 2 weeks ago. I like it better than the 17-40 that came in the same time. I have not had much of a chance to use the 17-40L because of having foot surgery about a month ago which really limited my outdoor activities.

50mm f1.8 + Tamron28-75

Do you think you'd use a 35mm more often if you had an f/2 ?

Hmmm. I seem to stay in the 50mm plus range a lot. If I had the 35mm F/2, yes I would use it. A wider prime is on my list to purchase in the next couple of months. But I still think the 50mm 1.4 would be a great first lens.

The tamron would be nice, but my main priority is good optics and a good build.

I think I will go with the 50mm 1.4 in the next month or so, though I have looked at the sigma 30mm. That has gotten some good reviews, but is a bit beyond my budget. Any experience with it?

askohen, i just got the sigma 30mm 1.4ex for around 390 bucks from amazon. They have a good deal going on it since its quite a bit cheaper there than all the other stores I checked at. If you are interested in that you might want to check it out. And yes, its a nice fast lens, quite sharp and helps get those very narrow DOF's. It also comes with a hood and a carrying case as an added bonus.

I know this has been discussed before..but it makes me ponder the cost/benefit of zooms vs primes. Back in the day, a lot of people just had their 50mm primes that hey bought with their bodies. I wonder if zooms have made us lazy, and I wonder if that could lead to inferior photography. Using a standard type prime may force me to move around more for the right shot and thus explore the subject more than if I had a zoom. So, I wonder if getting a prime vs a zoom would actually be good for my photography?