How is the Sigma 17-70mm f/2.8-4.5 at 50mm going to compare to the 50mm f/1.8 II?

I am just wondering how the Sigma 17-17mm f/2.8-4.5 at 50mm is going to compare to the Canon 50mm f/1.8.

Can anyone draw a comparison and point out a reason or reasons why a 50mm prime would be better than the Sigma at 50mm? Obviously the prime is faster but how will that really come into play?

The prime will be much sharper. It is calibrated just for 50mm where as the zoom lens basically recalibrates everytime you use it to zoom. Never mind the 1.8 is a faster fstop over the probably f4 at 50mm on the sigma lens. So the 50mm will have much much more bokeh (background blur) then the Sigma. Both are good lenses but both have different uses.

not fully sure what you're asking for, but my initial thoughts...

sigma tops the 50mm in wide-angle, convenience associated with zoom lenses and build quality.

the 50mm will give you sharp images at lower f-stops, and allow more opportunities to get the shot in low light as well as get nice images with bokeh. you can reasonably foot-zoom from the 40~60 range without too much hassle either.

not sure whether the sigma's AF is really better than the canon's. both supposedly hunt in low light.

I am asking mostly because I want to get into doing some portraits and I was wondering if the zoom will give me the same sharpness and bokeh that I would get with the 50mm f/1.8. I will have my camera and the Sigma lens tomorrow and I was thinking of getting the 50 prime for my indoor portraits but if the zoom will do the job then I don't need the 50 prime.

TMR Design wrote in post #2139255
I am asking mostly because I want to get into doing some portraits and I was wondering if the zoom will give me the same sharpness and bokeh that I would get with the 50mm f/1.8. I will have my camera and the Sigma lens tomorrow and I was thinking of getting the 50 prime for my indoor portraits but if the zoom will do the job then I don't need the 50 prime.

i guess you'll have to find out once you try portrait shots with the sigma. but i have a feeling you'll be getting the 50mm prime for portrait shots. hehe

i already have my portrait lens in the 85mm 1.8. i might consider adding the 50mm 1.4 eventually if i end up choosing the 17-40L as my walkaround.

i initially didnt want to spend more than $1500 (which my current setup almost adds up to. got enough room for a kit lens), but somehow, i got sucked into wanting a little bit more. i can get the 17-40L for a tad bit over 500 after rebates...and it's certainly tempting me greatly!

thrifty is a nice piece of glass to keep with you at all times. at f2.8 (if the focus is correct, which on the xt it won't be that often), it's sharper than my 70-200IS!

I'd be interested to see a comparison between these two.No doubt someone has both?

I have both, but I have never done any kind of real comparison. What I can say is that the 50 1.8 is just a sharper lens. If I knew I was shooting at 50mm, I would always put on my thrifty.

Stefan

I have both too, and there are times I swap the Sigma out for the 50. It's faster than the Sigma, so it's good for low light. Although I do find it hunts a little more in low light than the Sigma. The pictures are sharper, but that's the joy of primes isn't it?! Not to say the Sigma isn't sharp, because it is, just not "as" sharp.... And for the price of the lens, you really can't go wrong with this one... I think you'll want it for portraits, that's what sold me on it. In the shop I took a quick snap of my wife, and when I got home and viewed the picture on the computer I was sold.. Nice bokeh and the DOF was impressive. I did however have to ignore the expression on my wife's face, as she knew then what I was gonna do... =_) Lucky for me she is very supportive of my new hobby!!

Stefan A wrote in post #2140422
I have both, but I have never done any kind of real comparison. What I can say is that the 50 1.8 is just a sharper lens. If I knew I was shooting at 50mm, I would always put on my thrifty.

Stefan

That's what I thought you would say Stefan. I just needed to see and hear others say it.

gflatt wrote in post #2140679
I have both too, and there are times I swap the Sigma out for the 50. It's faster than the Sigma, so it's good for low light. Although I do find it hunts a little more in low light than the Sigma. The pictures are sharper, but that's the joy of primes isn't it?! Not to say the Sigma isn't sharp, because it is, just not "as" sharp.... And for the price of the lens, you really can't go wrong with this one... I think you'll want it for portraits, that's what sold me on it. In the shop I took a quick snap of my wife, and when I got home and viewed the picture on the computer I was sold.. Nice bokeh and the DOF was impressive. I did however have to ignore the expression on my wife's face, as she knew then what I was gonna do... =_) Lucky for me she is very supportive of my new hobby!!

OK now I am pretty sure I will be getting the nifty. If my camera arrives early enough I am going to go to a local shop and take a look at the National Geo bags and maybe pick up the lens too.

Hey Robert; I own both lenses and they're both workhorses. The Sigma is a very versatile lens that no other lens can touch for the money, Same applies to the Nifty-50, but you can't shoot a group portrait on a wedding with the Nifty, at the same time you can't shoot a candle-lit face at ISO-800 with the Sigma, but you can with the Nifty at F/2.2.. For what they cost, get both!

Thanks! Between what you guys have been saying and the images I have seen posted from that nifty I am convinced it is a lens I should have and will certainly switch to when I am doing (learning, that is) portraits.
I had a chance to play with a friends Nikon D70 with the obligatory 50mm f/1.8 and it really gave me a taste of what it can do and how responsive it is in low light as well as the bokeh and very nice DOF. Considering that it is available now for $69.99 I can't see how I can pass it up. I've paid $70 for silly useless crap in the past so why wouldn't I go for something sooooo cool and quite useful?