Fast Prime, 20mm-40mm for APS-C, good bokeh, <$300

Basically I'm looking for a prime lens on the cheap for my 600D. Right now I'm using the nifty-fifty (50mm/1.8). Great for portraits, too much tele for candids and walk-arounds. Eventually I plan on getting a full-body and using my current camera as the secondary, so I would prefer a EF lens…but I can always resell, right?

Basics: 20-40mm Prime on a APS-C. f/2.8 or better. AF necessary. FTM greatly desired. Good bokeh. Distortion, CA acceptable. Does not need to be built like a tank. Weight is not a problem.

From the Lens Purchasing FAQ
1) How "fast" does it need to be?
f/2.8 or less. IS system would be a luxury. I do a lot of low light shooting and I don't yet have a flash. (I would like to go ahead and get a 580EX II first so I have maximum automatic shooting until I get comfortable with manual flashes.)

2) Do you need it to be equipped with zoom?
No. Most likely a prime is what I'll get for this budget, and that's OK.

3) What size is acceptable?
Any. I'm a big boy (figuratively), I can carry extra weight.

4) Will it attract (un)wanted attention?
At this price point I'm not worried about that.

5) How does it focus?
I do need AF. FTM is almost a necessity: my 600D has trouble with low light focusing at even f/1.8. I do not want to keep switching between AF/MF on the lens when I realize its going to hunt rather than lock. The nifty-fifty has such loose tolerances I can slightly adjust focus manually while AF is engaged, which I find myself doing more and more.

6) What optical quality is needed?
a) sharp: At least as sharp as the nifty-fifty wide open (I just need to add a wavelet sharpening to make up for the softness wide open.)
b) vivid colors: At least neutralish coloring.
c) no chromatic aberration: Hoorah for PP, I can live with CA.
d) no geometrical effects: I can compromise here (PP).

7) Is it generally well-built?
a) sturdy: I do need a proper manual focus ring since I want to shoot video also.
b) weather-resistant: Can do without.
c) does it have internal zoom to prevent attracting dust while zooming? Can do without.
d) does it have internal focus, so that the hood won't turn when focussing? Necessary. My kit lens drives me nuts with this.
e) ease of use when zooming and focusing: Action does need to be reasonably smooth.

Thanks in advance!

35/f2?

Secondhand Sigma 30f/1.4

at the price you are looking at, I'd say EF 28/1.8 is your best bet. In US it might be over 300$ (not sure on US prices) but in EU it goes for around £250-320EUR or so.
It's very good wide open, especially in the center of the frame so on crop it would be sweet. It's focusing is very fast, you have ring type USM with full time FTM. Flare is a bit of an issue, but CAs are not bad. All that in a package that is not much bigger than 50/1.8 (roughly the size of EF50/1.4 USM), and very well built too.

I doubt on that budget of yours, you'll find better lens that meets all your requirements. Of course there is EF 40/2.8 STM but IMO it's just way too close to 50 (I used to have 40, 43, 50 and 55 on another system) and f2.8 for prime is really not that fast...

my 2p

sigma 30mm f1.4...the older version

EF 28mm f/1.8.

As others have pretty much said here already - EF 35mm f/2, Sigma 30mm f/1.4 EX DC HSM, or the EF 28mm f/1.8. The 35 f/2 and 28 f/1.8 are nice in that both can stay with you if you decide to go full frame in the future.

28 1.8

And get a used 40mm pancake for approx $100.00 when you get a chance

you mean the 28 f2.2 !

DreDaze wrote in post #16096536
sigma 30mm f1.4...the older version

Yep, this one. I love it on my 60D.

Sell the 600D and use the lens money to upgrade to a 5dmkii.

Another vote for the Siggie 30 1.4

Sigma 30mm!

IMAGE LINK: http://www.flickr.com …/29879962@N05/9​040449764/

IMAGE LINK: http://www.flickr.com …/29879962@N05/9​040481902/

Sigma 30 f1.4. Compare the old one (I have one and love it) to the new one to see it's weaknesses -- some distortion and some softness at the corners that the new version addresses. Some say focus problems both front/back, but also inconsistent focus in use -- I've not experienced that, but have found folks that are adamant they experience it. I shoot on a 40D so maybe in part that is why I'm happy . . .

40mm 2.8. Cheap and amazing IQ and relatively fast at 2.8