tamron 17-50 field curvature issue only at 17mm?

I've been reading up comparing the tammy 17-50 and the canon 17-55 because I need to replace my tammy 28-75 due to the fact that I don't use it as much since it starts at 28mm.

Anyway, my question is, as far as the field curvature issue with the 17-50, is this only a problem at 17mm and wide open? I rarely shoot at 17mm under f5.6 so if that's the only time it's an issue then I think I'm gonna pick this one up. Thanks in advance.

Dave

photozone.de stated:

"On the downside the extreme corners showed a very strong degree of field curvature at 17mm and a little less so at 24mm. This means that the focus plane isn't flat but it bends towards to corners. "

According to their report, the field curvature is reduced as you stop down.

Wilt wrote in post #4113345
photozone.de stated:

"On the downside the extreme corners showed a very strong degree of field curvature at 17mm and a little less so at 24mm. This means that the focus plane isn't flat but it bends towards to corners. "

According to their report, the field curvature is reduced as you stop down.

Yeah, I read that too. So does that mean the problem is non-existent after 24mm? Anyone have the lens that can comment from real-world experience with it? This is the only issue stopping me from getting it.

forsakenme720 wrote in post #4113372
Anyone have the lens that can comment from real-world experience with it?

In the real world people generally don't concentrate on the corners unless they are anal pixel peepers. Get it, enjoy it, you won't regret it.

asylumxl wrote in post #4113473
In the real world people generally don't concentrate on the corners unless they are anal pixel peepers. Get it, enjoy it, you won't regret it.

I'm certainly not a pixel peeper, but it would considerably bother me if I was shooting the front of an old building in Europe and its front was in focus in the center of the frame but out of focus at the edges of the frame, on a flat front!

I didn't really notice any at 17mm. I don't think it's a big deal unless you are mainly doing architectural photography.

This is taken at 17mm, and this is the full frame sideways (I cropped top and bottom). No additional sharpening and has been scaled a bit (2000 pixels wide) and compressed for web.

this is not a pretty picture, it was a bad picture actually, I have a few better takes that I didn't have time to find right now, but I wanted to show you a building with the Tamron.

As you can see both sides of the building look good, just as sharp as in the center, or perhaps a little softer, but for me is not really noticeable.

I like my lens very much and I never ever notice the supposed plane curvature.

http://www.worx3d.com/​forumpost/building.jpg (2000 pixels wide, 230kb)

Joel

Don't forget that DOF will mask field curvature! That does prove that typical shooting will often hide the issue quite nicely, as the example photo shows.

I forgot to mention that the picture was taken as follows:

1/50 sec at f/4.5, ISO100, 17mm, with my XTi

Honestly, I've never noticed the field curvature in any real world shots. Frankly, even in my own testing, I haven't really seen any field curvature. My 17-50 is very sharp, even in the corners, at 17mm f/2.8.

joruiz wrote in post #4113666
I forgot to mention that the picture was taken as follows:

1/50 sec at f/4.5, ISO100, 17mm, with my XTi

And a 17mm lens focused at something 100' away at f/4 has DOF of 13'-infinity.
And a 17mm lens focused at something 200' away at f/4 has DOF of 17'-infinity.

...why you would not expect to see much evidence of field curvature. Proving the point about 'not going to notice in most everyday shooting'

Jman13 wrote in post #4113729
Honestly, I've never noticed the field curvature in any real world shots. Frankly, even in my own testing, I haven't really seen any field curvature. My 17-50 is very sharp, even in the corners, at 17mm f/2.8.

And a 17mm lens focused at something 100' away at f/2.8 has DOF of 17'-infinity.
And a 17mm lens focused at something only 10' away at f/2.8 has DOF of 7'-19'.

Once again, proving the point about 'not going to notice in most everyday shooting'

Thanks everyone. You've all been a great help.

Dave