Sigma 17-70mm F2.8-4 vs Sigma 17-50 f2.8

Hi,
I am planning to buy one of these lens, but confused among these 2 . The advantage 17-50 f2.8 gives constant aperture and 17-70 give longer range than the 17-50mm and it is cheaper by $100.
My requirement is to get IQ and AF with less use of flash indoor (basically family pics).
Which you suggest is good? Which would you choose if you had the option & why?
Thanks

Since you already have a 55-250mm, I'd opt for the 17-50mm to get that constant f/2.8. Both appear to be great lenses though and variable aperture isn't that big of a deal IMO.

I'd say go with the 17-50, but if you really want less flash, then maybe stretch for the 18-35/1.8 or for cheaper the 35/2 IS or a 30/1.4.

I owned the first version of the 17-70mm It was a great lens I just never got used to the varible aperture. I then next got the Tamron 17-50mm non stabilzed version used it for a couple of years and it too was a great lens but hunted focusing in low light. About two years ago I upgraded to the Sigma 17-50 2.8 OS and love it! Much more reliable focus!

I have had zero focusing issues with the Tamron 17-50 (non-VC). I recommend it.

I've had both the Tamron and now the Sigma. I love the Sigma lens. Much sturdier, quiet, and the OS is quite nice. The Tamron took some really great photos, but I feel the Sigma is light years better in terms of quality. Though you can't beat the Tamron price .

My Sigma was a Japanese import that only cost $370 new, just no warranty.

Of the two, for what you want to use it for, I'd say go withe the 17-50 f2.8.

If you can afford the cost I'd say try the sigma 18-35 f1.8. Less range but amazing IQ and an extra stop and 1/3 of light over f2.8

It's always about tradeoff. You give up a little sharpness with the 17-70. I happen to love my 17-70 but there are times I need some additional sharpness and I fall back to my 50mm or 30mm primes. I'm thinking about adding a 17-50 f2.8 to my kit for when I need the extra sharpness. It's usually most noticeable when I need to crop an image but again, when you can go up to 70mm you have less need to crop in post.

If I were you, I would go with a used copy of the NEWEST version of the 17-70 that has SLD glass and is even sharper than the one I have now. Then if you aren't happy, it will be easy to sell and you won't eat much depreciation - if you lose any at all.

Thanks all.. what I really want is to use in indoor without using flash and also without maxing the ISO. Last time when I had taken pictures on Easter day @ my friends place, I had some shot which was fine.. some was very blurry. I missed some of the very good moments which turned to be very blurry. This made me really bothered and that was when I decided to change the lens. Ofcourse budget is limited. maybe I might lean to Sigma 17-50 f2.8 unless someone provide me better option for another lens.

robienyshe wrote in post #16883729
Thanks all.. what I really want is to use in indoor without using flash and also without maxing the ISO. Last time when I had taken pictures on Easter day @ my friends place, I had some shot which was fine.. some was very blurry. I missed some of the very good moments which turned to be very blurry. This made me really bothered and that was when I decided to change the lens. Ofcourse budget is limited. maybe I might lean to Sigma 17-50 f2.8 unless someone provide me better option for another lens.

That kind of depends on how much you need the zoom while you are in those low light situations. Either way, I would add the Canon 50mm f1.8 to your kit. You can get it refurbished for about $100 or used for about $75. It's really VERY sharp for such an inexpensive lens earning it the name "nifty fifty". Sigma's 30mm f1.4 is really sharp and fairly inexpensive and fast. But you lose zoom capability. A 17-50 or such will give you a lot more accurate AF with less hunting in the dark than the 17-70.

There really are just too many nuances to figure this out on paper. And even if you landed on the "right" lens now, there's a good chance that at some point in the not-too-distant future, you'll decide you want something else. That really is the beauty of owning an interchangeable lens camera. You are never stuck with any particular lens so you don't have to put so darned much research into making sure you get exactly the right thing. So be adventurous. Flip a coin and buy one. Then if it doesn't do what you want, make notes about why it doesn't and work from there. And buy used if you want to reduce or eliminate depreciation while you explore lenses.

2.8 just isn't fast enough to go without flash on a crop camera. Maybe if you had a 6D and the high ISO ability there then yes. I would look into balancing your flash with ambient lighting. That means you will need to gel the flash with a CTO filter if you are shooting in a tungsten environment and so forth.

Your other options are faters lenses like the 18-35/1.8, 30/1.4, 28/1.8, or 35/2's, but I will tell you that the images will come out much nicer if you are balancing bounced flash with ambient using smaller aperatures available in a 2.8 zoom.

FEChariot wrote in post #16883868
2.8 just isn't fast enough to go without flash on a crop camera. Maybe if you had a 6D and the high ISO ability there then yes. I would look into balancing your flash with ambient lighting. That means you will need to gel the flash with a CTO filter if you are shooting in a tungsten environment and so forth.

Your other options are faters lenses like the 18-35/1.8, 30/1.4, 28/1.8, or 35/2's, but I will tell you that the images will come out much nicer if you are balancing bounced flash with ambient using smaller aperatures available in a 2.8 zoom.

You do realize that you're only talking about a 1 1/3 stop difference from f2.8 to f1.8, right? Just because it's a crop doesn't mean you suddenly need a flash at f2.8 that would magically work on a full frame camera. I assure you that I shoot plenty of indoor shots on my 7D at f2.8 and f4 without the need for flash and without pushing my ISO to the point of ugly.

kfreels wrote in post #16884214
You do realize that you're only talking about a 1 1/3 stop difference from f2.8 to f1.8, right? Just because it's a crop doesn't mean you suddenly need a flash at f2.8 that would magically work on a full frame camera. I assure you that I shoot plenty of indoor shots on my 7D at f2.8 and f4 without the need for flash and without pushing my ISO to the point of ugly.

1-1/3 stops is like going from ISO 2500 to 6400 and 3200 is about my personal limit on a 7D. Sure there are Photoshop wizes out there that can clean that up, but I'm not one of them.

FEChariot wrote in post #16884279
1-1/3 stops is like going from ISO 2500 to 6400 and 3200 is about my personal limit on a 7D. Sure there are Photoshop wizes out there that can clean that up, but I'm not one of them.

right. but' it's also the difference from 1/60 to 1/25. Or ISO 3200 and 1/30. I don't like shooting over ISO 1600 myself. I just don't think you suddenly need a flash because you don't have a 1.8 lens instead of a 2.8 lens. The 1.8 lens is still going to be pushing it in crappy light and a flash would be helpful in both cases. If the light isn't that crappy, both can get by without just fine. Of course the 1.8 will be a little better but the zoom range changes (or is completely lost with a prime) and that may be a perfectly sensible trade-off depending on the shooter's needs and situation.

kfreels wrote in post #16885046
right. but' it's also the difference from 1/60 to 1/25. Or ISO 3200 and 1/30. I don't like shooting over ISO 1600 myself. I just don't think you suddenly need a flash because you don't have a 1.8 lens instead of a 2.8 lens. The 1.8 lens is still going to be pushing it in crappy light and a flash would be helpful in both cases. If the light isn't that crappy, both can get by without just fine. Of course the 1.8 will be a little better but the zoom range changes (or is completely lost with a prime) and that may be a perfectly sensible trade-off depending on the shooter's needs and situation.

Toally agree on the flash part. You are talking about some pretty slow shutters there so can I assume you are talking about shooting stationary subjects then and not live subjects? 1/30" is going to guaranty me a blurred image because I shoot mostly people. I prefer to keep it above 1/80". However if I am shooting stationary subjects, the 4 stops of OS in my 17-50 is more than enough to shoot without flash.