Fast wide thoughts.

I need a lens for taking indoor photos in a darker house. F2.8 requires, 1600 ISO with a 1/125 shutter speed. I can't adjust the shutter speed any lower or I'll get 5 year old motion blur. My camera t3i can't do ISO higher than that well either. So I need a bigger aperture. (At least that's my thinking correct me if I'm wrong. Oh and no flash.)

I'm trying to do this pretty economically. Third-party is fine with me. I'm looking at 24-35mm primes. I looked at the Sig 18-35 F1.8 but that's the top top of my budget and I do nee very reliable AF. There's a 28 1.8, sigma has a 30 1.4, then there are a lot of 35 in the 1.4, 1.8, 2 range.

It's a crop body so the 50mm1.4 which I already have is a little to long. Post your thoughts and advice please.

Travis, I have the Sigma 30 1.4 I think it is a stellar lens. I have the same camera body as you and the 30mm is equivalent to the 50mm on a crop and that is pretty close to what the human eye sees at.
Now if you can afford the 18-35 1.8 from Sigma, you won't find me trying to convince you out of that purchase. I have heard way too many good things about that lens to discount it if you have the money.
I have a refurb 17-40 I just got from Canon and have found I really love that range, but it would not be fast enough for you without supplemental light.

Hows the AF on that?

See I don't have the budget for the 18-35 but if it's really the best option I might be willing to wait until I did.

Sometimes I wish I still had a crop body to use that sigma 18-35 on.

why no flash? it's the best option to stopping the motion of a 5 year old running around...

Dont forget Samyang for fast/wide/inexpensive.​..but of course no AF.
I've played with the Sigma 35 1.4, very very sharp and speed a given but 35 is often (even on full frame) not wide enough for me. I also have the Sigma 12-24 and find it only usefull (for me) doing outside landscape or on a tripod inside....I compare it to the Nex 10-18 IQ wise and find they both serve the same purpose. The Sigma 18-35mm because of its speed advantage is on my short list.

travisvwright wrote in post #16345746
I need a lens for taking indoor photos in a darker house. F2.8 requires, 1600 ISO with a 1/125 shutter speed. I can't adjust the shutter speed any lower or I'll get 5 year old motion blur. My camera t3i can't do ISO higher than that well either. So I need a bigger aperture. (At least that's my thinking correct me if I'm wrong. Oh and no flash.)

I'm trying to do this pretty economically. Third-party is fine with me. I'm looking at 24-35mm primes. I looked at the Sig 18-35 F1.8 but that's the top top of my budget and I do nee very reliable AF. There's a 28 1.8, sigma has a 30 1.4, then there are a lot of 35 in the 1.4, 1.8, 2 range.

It's a crop body so the 50mm1.4 which I already have is a little to long. Post your thoughts and advice please.

Heya,

Edit: Herp-ta-derp, just realized you already have a 50mm 1.4, sorry.

Remember you have a crop sensor, so those short primes are longer than you think.

How wide do you need it to be?

The EF 50mm f-1.8 II (nifty fifty) is $100 and is a very fast lens, autofocus is decent, and it takes nice sharp photos and can function fairly well in low light with your ISO and a faster shutter speed. It's effectively 80mm on a crop sensor. If that's not wide enough, then you'll have to find another option of course, but it's a very inexpensive way to get fast.

Alternatively the 35mm f-2 is fast and is effectively like a 50mm on your crop if you need wider angle.

Some other, more expensive, fast-wide options for a crop sensor:

EF 28mm 1.8 USM (effectively 44.8mm)

Sigma 18-35mm 1.8 (Very wide, very fast, with range options)

Tokina 11-16 f2.8 (Very very wide, still decently fast)

Sigma 20mm 1.8 (Wide & fast)

+++++++++++++++

Here's an example of the EF 50mm f-1.8 MK II on my T4i (similar to your camera, a crop sensor too):

I raised the shutter speed to 1/500, f-1.8 (wide open), with 1600 ISO so mimic your needs (no motion blur at that shutter speed, still maintains appropriate lighting, I did this in a dark room with the blinds shut literally just now for you to show an example). The puppy is not cropped or processed in any way, this is from the camera to you. The hand photo, I did change levels/saturation to see what it would do.

I have the 30/1.4 older EX version, and I don't even try to shoot at f/1.4 when my kids are moving around. It's better to use 2.0 to keep the DOF a little wider to help with the keeper rate from focus inaccuracy and I'm using a 7D which is already much better at AF than your t3i. I don't know if the focus accuracy was improved much on the new art version or not. I would think the 35/2 IS would give the best servo AF performance of the lot.

travisvwright wrote in post #16345746
I need a lens for taking indoor photos in a darker house. F2.8 requires, 1600 ISO with a 1/125 shutter speed. I can't adjust the shutter speed any lower or I'll get 5 year old motion blur. My camera t3i can't do ISO higher than that well either. So I need a bigger aperture. (At least that's my thinking correct me if I'm wrong. Oh and no flash.)

I'm trying to do this pretty economically. Third-party is fine with me. I'm looking at 24-35mm primes. I looked at the Sig 18-35 F1.8 but that's the top top of my budget and I do nee very reliable AF. There's a 28 1.8, sigma has a 30 1.4, then there are a lot of 35 in the 1.4, 1.8, 2 range.

It's a crop body so the 50mm1.4 which I already have is a little to long. Post your thoughts and advice please.

Your camera is capable of the no-cost solution of shooting at ISO 6400. For best results, you will have to shoot raw, with some +EC, and spend at least a few minutes with DPP or LR, processing the images. With good lighting, your ISO 6400 shots can equal the in-camera jpg shots at 1600.

Here is a quick 90-second edit on a raw file. 60D, 15-85, f/8, 1/50, +1EC, ISO 6400, 85mm from about 4 feet.

MalVeauX wrote in post #16345892
Here's an example of the EF 50mm f-1.8 MK II on my T4i (similar to your camera, a crop sensor too)

he already has the 50mm f1.4...

Travis, the AF on the Sig 30 is outstanding. I use it to shoot a lot of low light indoor shots, including martial arts shots which there is a lot of action and it still meets the needs.
I will emphasize that in REALLY low light, I definitely rely on my external flash to stop the action. I used the on board flash only briefly before I bought a cheap, but very functional 3rd party flash. And now I am not as concerned about the fast glass. Adding the needed light with my flash has allowed me to get cheap L glass.
Will I ever get rid of my fast primes? No way in heck!

DreDaze wrote in post #16346036
he already has the 50mm f1.4...

Must have missed that, as I don't see it in his posts or anything.

If I just wasted your time, apologies.

Very best,

MalVeauX wrote in post #16346055
Must have missed that, as I don't see it in his posts or anything.

If I just wasted your time, apologies.

Very best,

it's not a waste of my time...no need to apologize at all...it was at the end of his first post

travisvwright wrote in post #16345746
I need a lens for taking indoor photos in a darker house. F2.8 requires, 1600 ISO with a 1/125 shutter speed. I can't adjust the shutter speed any lower or I'll get 5 year old motion blur. My camera t3i can't do ISO higher than that well either. So I need a bigger aperture. (At least that's my thinking correct me if I'm wrong. Oh and no flash.)

I'm trying to do this pretty economically. Third-party is fine with me. I'm looking at 24-35mm primes. I looked at the Sig 18-35 F1.8 but that's the top top of my budget and I do nee very reliable AF. There's a 28 1.8, sigma has a 30 1.4, then there are a lot of 35 in the 1.4, 1.8, 2 range.

It's a crop body so the 50mm1.4 which I already have is a little to long. Post your thoughts and advice please.

DreDaze wrote in post #16346058
it's not a waste of my time...no need to apologize at all...it was at the end of his first post

Thanks, some how I totally glossed over that completely. Derp di derp on me.

Very best,

DreDaze wrote in post #16345844
why no flash? it's the best option to stopping the motion of a 5 year old running around...

My thoughts exactly. I think OP is stuck in that mindset that flash creates "un-natural" looking light.

OP, try using a business card or other piece of paper (business cards work well because they'll stay there without you needing to hold them) in front of your pop-up flash, this will act as a bounce and eliminate red-eye exposures, harsh light and thrown white balance. You can achieve great results with flash if you take the time to experiment with it

Oh, this is also a no-cost solution