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Old Mar 28, 2010, 9:17 PM   #1
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Default Tamron vs sigma 70-200mm... One More time

I am looking to acquire a fast telezoom (70-200mm, f2.8) for HS Football. I know the Sigma is superior as far as fast autofocus, but will Tamron get the job done? I will also be using the lense for wildlife photography and it is important for me to be able to utilize a tc and still have AF capabilities. I am willing to make some concessions with the AF speed, if I can have a more versatile lense. I'm leaning towards the Tamron, but need some help dexiding. Also, if I do go w/ Tamron what are my best options for a TC?
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Old Mar 28, 2010, 9:23 PM   #2
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I would check out this thread, seems that the sigma may be a better option for sports then the tamron.


http://forums.steves-digicams.com/so...-canon-7d.html
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Old Mar 29, 2010, 5:31 AM   #3
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Welcome to Steve's.

Which body do you have?

The Tamron is the sharpest but the focus is slow making it a poor choice for sports. The Sigma is the better option but doesn't take a 1.4x TC all that well when using the long end of the lens.... it works but depends on what you are happy with quality wise. Admittedly I've not used the vII lens with a TC, only the v1 so I can't say how much it was improved so hopefully someone else can jump in who has this (can't think of anyone) and post some samples with a TC.
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Old Mar 29, 2010, 6:12 PM   #4
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Hi sbluems,

Welcome to the forum!

I think that Mark's question is very pertinent. The model is very important when talking about AF performance with Pentax. Also, there have been (I believe) 4 models of the Sigma, but I'll assume that you're talking about the currently available one.

Sigma -- With this lens, AF is achieved with HSM (an in-lens motor). This is both good and not so good. The good is that it focuses faster, and is silent. The bad is that there are no TCs (other than one that focuses within the TC) that is a sure thing to AF reliably with any of the in-lens motored AF lenses (SDM or HSM). There are reports from some users that one or more of the PZ capable TCs will work with a given individual lens, but AFAIK, there is no real consensus, and I think that some of these testimonials stretch the definition of "work" beyond what I'd consider acceptable. Let me state that again. SDM/HSM (any of them) lenses may not AF acceptably with pass through AF TCs (TCs that AF using the focusing elements of the lens), regardless of who it's made by, with any of the Pentax DSLRs, regardless of model of the body or lens.

Also, HSM or SDM only lenses will not AF with the D, DS, DS2, DL, or the K100 or K110. HSM/SDM will AF with the K100S, and all the other K series lenses.

Tamron -- this lens uses the older screw drive AF system, and the motor is located in the camera body. AF is louder and sometimes slower (depending on both the lens and the body). Pluses are that it's a bit lighter in weight (which can be important with a lens this size), and the screw drive AF system will work with any of the AF TCs available for the K mount, within reason. The qualifications to how well it will work are that a TC will likely slow down the AF speed to an expected degree, and the light loss (1 stop for each "x") will limit the situations (light levels) that the TC will focus acceptably.

If 200mm is enough reach, and you have a Kx or a K-7, then either of the lenses will probably work for you. From what I've read, the Sigma is faster focusing. If you think you'll want to use a TC with AF to any significant degree, then the only lens to get at this time would be the Tamron because of TC compatibility issues.

I realize that some of this answer may be a bit cryptic. If you want a better explanation, just ask, and I'll try to supply more details.

Scott
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Old Mar 29, 2010, 8:10 PM   #5
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Thanks for the detailed responses, everyone. I've been agonizing over this decision for two weeks and have researched the best I could. The body is the K2000D (entry level). I realize that the Sigma is superior in the AF category (at least from everything I've read), but with the new lens there are no options for a tc. If the Tamron can AF fast enough w/o the tc, I'm good. Most of the sports shots will be w/o the tc, but I want to be able to use one for the wildlife shots. Does this help?

Also, there are Kenko lenses on the market that are K mounts, but don't have a pz in the model number. Will these not autofocus nwith the Tamron?

Thankks, again.
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Old Mar 30, 2010, 1:31 PM   #6
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Quote:
Originally Posted by sbluems View Post
Thanks for the detailed responses, everyone. I've been agonizing over this decision for two weeks and have researched the best I could. The body is the K2000D (entry level). I realize that the Sigma is superior in the AF category (at least from everything I've read), but with the new lens there are no options for a tc. If the Tamron can AF fast enough w/o the tc, I'm good. Most of the sports shots will be w/o the tc, but I want to be able to use one for the wildlife shots. Does this help?

Also, there are Kenko lenses on the market that are K mounts, but don't have a pz in the model number. Will these not autofocus nwith the Tamron?

Thankks, again.
Hi sbluems,

AFAIK, any AF TC will work with the screw drive AF of the Tamron. The Kenko, Tamron, and Sigmas have been recognized by most users as the best optically of the AF TCs.

I've also heard from reliable sources that the Promaster 1.7x TC is a good one if you want something more than the 1.5x class. With a 1.7x, you'd lose 1.5 stops of light compared to the 1 stop loss from a 1.4x or 1.5x. Personally, I've not had any 2x TCs that have overly impressed, but I haven't tried them all, so can't comment on these. My favorite is the Pentax F 1.7x Auto Focusing Adapter, but it's a totally different concept from any other TC in that the AF focusing elements are in the TC, and allows AF within its focusing range with any lens, MF or AF.

Your K2000 AF will probably perform reasonably well with the Tamron, but either the Kx or the K-7 AF is quicker with the new AF algorithms. Both can also get better higher ISO performance, so you'd be able to use faster shutter speeds at a given light level -- sometimes you need all the help you can get, and unfortunately amateur sports is one of those genres since the lighting is never as good as it is in professional venues. I'm primarily a birder, and have similar needs.

Scott
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