Tamron 17-50 and sigma 18-125 Sharpness comparison

Ok it's obvious that tamron easily beats the sigma due to huge difference between ranges of these glasses. However I wonder that how big the difference of IQ results of them.
I think 50mm reach is enough for me (at least I've never confronted with any case I need to use more reach) but as a travel lens more reach maybe a better option.
Another point is that there is a considerable price difference as a reason for me to go with sigma but still I'm nervous about sharpness of it.

Is there any user who used both of them to compare.

http://the-digital-picture.com …&SampleComp=0&F​LI=0&API=2

On a such chart it is quite prominent. However the point I wonder is that whether it is easy to distinguish the quality on a portrait, landscape or any kind of still ?

lzooml wrote in post #10901396
On a such chart it is quite prominent. However the point I wonder is that whether it is easy to distinguish the quality on a portrait, landscape or any kind of still ?

Depends on how big you print and what apertures you use. Stopped down to f/8, the 2 lenses are comparable.

996gt2 wrote in post #10901513
Depends on how big you print and what apertures you use. Stopped down to f/8, the 2 lenses are comparable.

f/8 is too narrow to utilize them, so you mean otherwise they are not comparable.

Personally, I would just assume buy and use a point and shoot over the Sigma. But I do own the Tamron, and it's a pretty nice lens at a reasonable price. For longer shots I have a 70-200. Plenty sharp, but also heavy.

SnapLocally.com wrote in post #10902531
Personally, I would just assume buy and use a point and shoot over the Sigma. But I do own the Tamron, and it's a pretty nice lens at a reasonable price. For longer shots I have a 70-200. Plenty sharp, but also heavy.

Huh???

Sorry about the confusion...

I'd rather buy a Point and Shoot camera over a 2nd rate lens if I wanted to take "ok" shots. Personally I wouldn't "invest" in the 18-200, so I guess I'm saying I'd rather have a new camera altogether than an "ok" lens.

SnapLocally.com wrote in post #10904150
Sorry about the confusion...

I'd rather buy a Point and Shoot camera over a 2nd rate lens if I wanted to take "ok" shots. Personally I wouldn't "invest" in the 18-200, so I guess I'm saying I'd rather have a new camera altogether than an "ok" lens.

I tripped around SE Asia for a few years with only a 350D/grip plus a Sigma 18-200mm nonOS and brought back the shots.. I got stuff impossible to get with a P&S..

I notice a gigantic difference between the Sigma 17-70 that I have now and the Sigma 18-125mm OS that I recently sold. The Tamron 17-50 tests a little better than the 17-70. I believe you will notice the difference immediately, and especially at wider apertures.

I just got a Sigma 18-125 OS for the range. I reasoned that compared to the 17-50 non VR which is about the same price used, I had a similar level of low light shooting becuase of the OS as long as the subject wasn't mooving. I have been on two vacations with it and really enjoy the range, but part of me still feels like I would like the depth of field, sharpness, and low light capabilities of the 17-50. I still have a few days left to return it to Amazon and i'm thinking I may do so...then I would have to get a telephoto lens though...

Also, check out this comparison by lightrules for some real world examples:

http://www.pbase.com/l​ightrules/image/986625​85

Check my website for some "real world" examples. Here's a couple of action shots with the 18-125, I'd say they're far from soft.

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IMAGE LINK: http://www.stevemokanp​hotography.com …w9wQ#897127486_​8XvG8-A-LB

Those are nice samples. I think some people mistake "not as sharp" with the word "soft". Nobody said the 18-125 was soft. I thought that it was a decent lens, especially given the zoom range. But compared to higher grade short zooms and especially most f2.8 zooms, it is on a different level. Doesn't mean it is a bad lens, just that it does not quite have the same picture quality.

That said, moving to a 17-50, you will really miss the zoom range!

lzooml wrote in post #10901396
On a such chart it is quite prominent. However the point I wonder is that whether it is easy to distinguish the quality on a portrait, landscape or any kind of still ?

Also prominent when Pixel Peeping at 100%+, however ......

996gt2 wrote in post #10901513
Depends on how big you print and what apertures you use. Stopped down to f/8, the 2 lenses are comparable.

When the ink hits the paper, that is all that matters.

Even if you don't make prints, when the image is processed out to what it will be displayed on in most cases it won't make a difference.

Those chart comparisons are important though, I mean they will show you under those circumstances what the lens is capable of.

I have the Tamron 17-50, even so I am looking for another lens though I suspect once I undertake the project I am lining up the 17-50 is going to see a lot of use. So much so that I am practicing with it on a regular basis. I don't want any mistakes!