Anyone live in SF and have the Tamron 17-50 2.8 non IS?

I live in San Francisco and was wondering if anyone has the Tamron 17-15 2.8 without the VC (image stabilization) that I can compare my lens with your copy. The reason is that my copy is tact sharp at 2.8 on any focal length, however, it requires that I first zoom into 50mm and focus lock it, then zoom back out to whatever focal length I want. If I don't do this, then the 2.8 isn't as sharp or sharp. I don't know if this is normal or not. Let's call my current copy Lens A.

I've had other copy of this lens (let's call this lens B), and what's wierd is that at f/2.8, 50mm, Lens B is out of focus a bit at the center as if I'm taking a flower, however, when shooting at a wider angle without any sort of the above focus lock and adjustment trick, lens B is sharper in the wide angle than Lens A. Therefore, I'm not sure if this is a design issue or not and so I'd like to see someone else's sharp copy.

I hate to send it in and have Tamron mess with it IF my copy is as good as it gets, but on the other hand, I can't stand the constant zooming in and out just to make sure all pictures are sharp at f/2.8.

Thanks,
Gordon

My Tamron 17-50 f/2.8 non-VC does not do that. My only complaint about focus is that once the light gets so low, it does not focus well enough to produce a sharp image at any focal length. Even the focus assist from my 430EX II doen't help much.

I am talking f/2.8, ISO 6400 and 1/30 or so. I don't think a lot of equipment performs well at those levels, though. At 1/30, with no IS it may not be entirely my equipment's fault.

gordon m wrote in post #16203823
I live in San Francisco and was wondering if anyone has the Tamron 17-15 2.8 without the VC (image stabilization) that I can compare my lens with your copy. The reason is that my copy is tact sharp at 2.8 on any focal length, however, it requires that I first zoom into 50mm and focus lock it, then zoom back out to whatever focal length I want. If I don't do this, then the 2.8 isn't as sharp or sharp. I don't know if this is normal or not. Let's call my current copy Lens A.

I've had other copy of this lens (let's call this lens B), and what's wierd is that at f/2.8, 50mm, Lens B is out of focus a bit at the center as if I'm taking a flower, however, when shooting at a wider angle without any sort of the above focus lock and adjustment trick, lens B is sharper in the wide angle than Lens A. Therefore, I'm not sure if this is a design issue or not and so I'd like to see someone else's sharp copy.

I hate to send it in and have Tamron mess with it IF my copy is as good as it gets, but on the other hand, I can't stand the constant zooming in and out just to make sure all pictures are sharp at f/2.8.

Thanks,
Gordon

Sounds like you need a different MFA at wide vs long end. Only the newest bodies support that. If your body does not then you are stuck. Either needs to be sent in for adjustment or exchanged for another copy.

(I do have the lens in question and was in SF.... three weeks ago but it sounds like the problem is clear, the lens has a different calibration wide vs long (mine does not) so unless you have a 5D3/1DX/6D you are stuck unless it is swapped or sent in.)

What's MFA? I don't understand the rest of the message.

wombatHorror wrote in post #16205476
Sounds like you need a different MFA at wide vs long end. Only the newest bodies support that. If your body does not then you are stuck. Either needs to be sent in for adjustment or exchanged for another copy.

(I do have the lens in question and was in SF.... three weeks ago but it sounds like the problem is clear, the lens has a different calibration wide vs long (mine does not) so unless you have a 5D3/1DX/6D you are stuck unless it is swapped or sent in.)

Are you saying that a lens can have both a Wide angle and a long end calibration done on one lens? I didn't know there's two separate calibrations.. i thought there is only one calibration. Even with incamera micro adjustments, there's only one setting right, you calibrate it for the entire lens, adn nothing about taking different calibrations for wide angle vs. long on a zoom is there?

Thanks,
Gordon

wombatHorror wrote in post #16205476
Sounds like you need a different MFA at wide vs long end. Only the newest bodies support that. If your body does not then you are stuck. Either needs to be sent in for adjustment or exchanged for another copy.

(I do have the lens in question and was in SF.... three weeks ago but it sounds like the problem is clear, the lens has a different calibration wide vs long (mine does not) so unless you have a 5D3/1DX/6D you are stuck unless it is swapped or sent in.)

Newer bodies (5D3, 6D, 1DX) can set micro-focus adjust (MFA) for each end of any zoom lens. While using the lens, the camera automatically adjusts the MFA amount for the selected focal length. For what its worth, I don't think this will help your problem.

I've used the Tamron 17-50 non VC.
Mine was sharp throughout the range... always.

The only downsides compared with my Canon 18-55 "kit" lens were:
The AF is slower on the Tamron.
The Tamron struggles just as much as the Canon to focus in low light.
Don't get me wrong, for the price the Tamron is good, just not that much better than the kit lens.

PH68 wrote in post #16206997
I've used the Tamron 17-50 non VC.
Mine was sharp throughout the range... always.

The only downsides compared with my Canon 18-55 "kit" lens were:
The AF is slower on the Tamron.
The Tamron struggles just as much as the Canon to focus in low light.
Don't get me wrong, for the price the Tamron is good, just not that much better than the kit lens.

I beg to differ. F/2.8 from 17mm through 50mm is 'that much better than the kit lens." People pay thousands for two stops of light. It is rather a big deal to me.

Price a 400 f/2.8 against a 400 f/5.6. See what I mean?