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12-21-2009, 01:42 PM   #1
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Tamron 70-200 f/2.8 auto focus question

Is the Tamron 70-200 f/2.8 screw-drive or internal motor lens?

Does anyone have experience with the AF speed and accuracy of this lens with K-x or K-7 ?

What other lens choices are there for the 70-200 range that are fast focusing and suitable for sports (ice skating in this particular case) ?

Regards,
Stanjo

12-21-2009, 01:50 PM   #2
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My tamron 70-200/2.8 focus really fast on my k-7
The lens is screw-drive and very high IQ.
12-21-2009, 02:19 PM   #3
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QuoteOriginally posted by netuser Quote
My tamron 70-200/2.8 focus really fast on my k-7
The lens is screw-drive and very high IQ.
Nice to know you are happy with the Tammy because I am in the process of buying one!

So, this 500mm f4.5 ... is this a Sigma or the "old" Takumar 500mm f4.5 M42 ?
That must be quite a beast to lug around!
JP
12-21-2009, 02:22 PM   #4
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I'm saving for the sigma

About the tamron 70-200, I'm pretty happy with it. Great IQ, very accurate concerning focus and fast . (Also on my k200d)

12-21-2009, 02:30 PM   #5
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to make the short story long ...

I was taking pictures of my 4 years old son learning to ski at the ice rink. He is not too fast as you can guess.

I was with a K100DS + Tamron 28-75 f/2.5, late afternoon, cloudy weather.
First thing I realized I needed a longer lens, hence my interest in 70-200 range.

Second, my frustration when I couldn't get a focus lock. I would either miss the shot in AF-S or be out of focus in AS-C. Out of a 100 clicks, I probably got 2-3 good shoots.

The guy next to me with a Canon Rebel + Canon 70-200 f/4 IS was making every shot count. Embarrassed, I asked him to use his camera to take a picture of my kid and exchanged e-mails to send me the picture. What can I say - you cannot take bad picture with the Canon setup - just click away and they all come out in perfect focus.
My wife with a p&s Fuji f40fd captured good moments too.

Now, I'm thinking, maybe with a k-7 or k-x and an internal motor lens I should do much better, par with the Canon. But I would hate to spend $$$ on a new body + new lens just to get more of the same.
12-21-2009, 02:37 PM   #6
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Pentax is not known for the fast AF speed.

You can antecipate and/or instead of doing machine gun shooting (canon/nikon style) go for the snipper type.

Better try to learn this too "techniques"
12-21-2009, 02:43 PM   #7
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QuoteOriginally posted by stanjo Quote
I was with a K100DS + Tamron 28-75 f/2.5, late afternoon, cloudy weather.
First thing I realized I needed a longer lens, hence my interest in 70-200 range.

Second, my frustration when I couldn't get a focus lock. I would either miss the shot in AF-S or be out of focus in AS-C. Out of a 100 clicks, I probably got 2-3 good shoots.

The guy next to me with a Canon Rebel + Canon 70-200 f/4 IS was making every shot count.
Now, I'm thinking, maybe with a k-7 or k-x and an internal motor lens I should do much better, par with the Canon. But I would hate to spend $$$ on a new body + new lens just to get more of the same.
I am certainly not a pro at that sort of "sport" photography but my guess is that lighting conditions did not permit AF locking? This is true even for "higher grade" cameras.
I am quite sure that your K100D, or any other newer cameras would have a hard time locking focus under such low light conditions.

That's my guess. Is the Kx/K7 going to solve that? I'll leave that to the pro's.

JP
12-21-2009, 02:47 PM   #8
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The ligh was not ideal, but sufficient. How did the Canon manage under the same conditions? Plus, the Canon lens is f4 open, mine f2.8 - I should have had the advantage for focus light.

I was shooting at f4.0 to get some extra DOF.

12-21-2009, 02:54 PM   #9
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Sniping in AF-S mode did not work as it will not confirm focus fast enough and will miss the shot.
In AF-C, it dosn't wait for confirmation to fire, but all my pics came out of focus.

What other technique is there ? (besides catch-focus with manual which is impractical in this case)
12-21-2009, 03:09 PM   #10
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Panning ?
12-21-2009, 03:12 PM   #11
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I have this lens and although does not contain built-in AF motor, it's still quite fast. It doesn't lock focus as good as my 50-135 but the screw-drive does move slightly faster than the SDM. It's sharp and high quality. I highly recommend this lens.

http://www.youtube.com/watch?v=9Ns-IiGYHXQ
12-21-2009, 03:14 PM   #12
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The kid was coming to you ? or just passing left to right or right to left ?
12-21-2009, 03:19 PM   #13
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QuoteOriginally posted by netuser Quote
The kid was coming to you ? or just passing left to right or right to left ?
It was a speed test, i was focusing on blank white wall. But for the locking, it still doesn't lock as good as the 50-135. When you AF on something, at times it tends to wobble it's ring slightly back and forth from left to right, and you can hear it just creep creep creep before it stops. Same thing happens with my Tamron 28-75, not sure if this is a Tamron thing but I really loved how the 50-135 just stops dead-on it's track without creeping or hunting.

Last edited by LeDave; 12-21-2009 at 03:25 PM.
12-21-2009, 03:36 PM   #14
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QuoteOriginally posted by LeDave Quote
It was a speed test, i was focusing on blank white wall. But for the locking, it still doesn't lock as good as the 50-135. When you AF on something, at times it tends to wobble it's ring slightly back and forth from left to right, and you can hear it just creep creep creep before it stops. Same thing happens with my Tamron 28-75, not sure if this is a Tamron thing but I really loved how the 50-135 just stops dead-on it's track without creeping or hunting.
I was asking the OP
12-21-2009, 03:38 PM   #15
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QuoteOriginally posted by netuser Quote
The kid was coming to you ? or just passing left to right or right to left ?
The rink is oval. My son was coming to me from the left - moving on both directions - forwards and sideways.

My real questions:
- I know from experience that the Tamron 28-75 did not cut it, can I expect the Tamron 70-200 to be better?

- Would a new body make a big difference?

- Is it the screw-drive that is inherently slow (with heavy tele lens) ?

- Are AA batteries (vs Li-Ion) inherently not strong enough to quickly move the heavy lens?
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