[JinDesu]

Don't let anyone fool you, both Tamron and Sigma are not sharp at 2.8, do some research and read several reviews
Why is 2.8 important, do you shoot at night? With the available lenses for Pentax you won't get the crisp sharp image you probably want, trust me, been there, done that...

Check (for example):
PhoDOGraf: Photography, Image Retouch & Manipulation - Coursing -20 Ronostrand

The Tamron 70-200 is really soft @ 2.8 but crisp @ 3.2.

I find that my Tamron 70-200 F2.8 is somewhat softer at F2.8 only from 150-200mm. Anything shorter and it is one of my sharpest lenses.

Full size images:
F2.8 @ 70mm - http://farm8.staticflickr.com/7256/6887737276_14557b585d_o.jpg
F2.8 @ 115mm - http://farm9.staticflickr.com/8164/7695312122_a440ed64e3_o.jpg
F2.8 @ 200mm (which I think is acceptably sharp, but maybe that's just me) - http://farm8.staticflickr.com/7011/6746262195_b13ab6caa8_o.jpg

Unfortunately most of my shots at 200mm was shot at F4 (where it is damn sharp) because the DOF was too thin for stuff I was shooting.
F4 @ 200mm - http://farm9.staticflickr.com/8304/8012788258_de24229851_o.jpg

So I just want to clarify for people reading - the Tamron 70-200 is not soft at F2.8, it can be soft at the longer ends of the focal lengths. I feel that my lens performs quite well regardless, and more often it is the thin DOF, misfocus, or motion blur from shooting at shutter speeds too low that ruin the image than the optical performance of the lens. And I've heard that the latest 2 Sigma 70-200s are as good or better than the Tamron 70-200, but I don't know how they perform over their range.

Oh, and with regards to sports - my lens focuses pretty slow compared to everything else I own. I depend heavily on prefocusing on certain spots to capture sport shots.

edit - one disclaimer, I shoot with a 12MP k-x. Lenses will look better on the k-x than on a k-3. I have, however, full confidence in my Tamron 70-200 to perform well on a k-3 in the 70-150mm range.

[kenyee]

I think he meant the Tamron 70-200 2.8 VC USD (Model A009) ;-)

Sadly yes...I was thinking about that.
The Tamron is pretty widely acknowledged to be sharper than the Sigma, especially after Sigma added OS which made the edges worse than even before.

I really wish the VC were available for Pentax

[DSims]

Well I own Sigma EX 70-200 ,Sigma EX DG 50 macro , da40 , Sigma 400 Telemacro , Sigma Bigma and multitude of cheap screw lens (28-80, 18-250, 70-300 etc etc)

In Sdm/HSM
I own da*16-50, da* 50-135 , da* 55 , da* 300 , Sigma ex DG OS HSM 70-200.

Models I have extensive experience of
k10d ,k20d,Kx, k5 and k3
I shoot an average 500+ sport images a week in low light varying from linear tracking to spot tracking.
I also have quite a lot of exposure to Canon / Nikon FF bodies with lens like Canon 200mm EF f2L

Don;t mistake focus 'speed' with tracking ability

High screw drive focus speed means low torque which in turn mean changing direction takes time....ie poor tracking ability

HSM (ring type) is moderately slow but because its direct drive and short throw makes it ideal for tracking.
The da* 300 suffers from too weak a motor needing ling throw and as such is a halfway house in performance.

as I said "all but the most 'sport' tuned glass are better."
So don't see that in conflict with "with some comments I've read from others (e.g. F*300 or FA*300/4.5 focus faster than DA*300)."

I don't know the fa300 but my Sigma 400 being short throw and rear focusing is fast (rear focus low weight and lower latency )

There is a reason screw is nothing but a legacy option dropped by most manufacturers , They didn't drop it because its better !

I figured you had good reason for saying this, which is why I asked.

It makes sense that an in-lens motor and AF mechanism can be best optimized for that particular lens. And Canon, for example, is going to optimize it for sports. But with the Pentax SDM lenses I've used this isn't true. So with a Pentax - especially a newer body like the K-5 II or K-3 - you might be better off with screw drive.

In Pentax branded lenses, it looks like you don't have any screw drive primes (that are long enough for most sport shooting) whereas I don't have any SDM primes. So it makes it hard for either one of us to compare, in this case. I have tried both the DA*200 and DA*50-135 and they were both disastrous for keeping runners in focus (who are coming toward me at full speed). The DA*300 is supposed to be substantially better, but I've never owned one (only tried it in the store) so I couldn't compare it for action. OTOH, the FA*85, FA135, and F*300 all do an adequate job (though I'm sure not nearly as good as an optimized Canon lens).


So I respect your experience, and I believe you're correct in principle (as well as in practice for many other brands). But because of the fact that Pentax SDM has generally not been optimized for action, I believe Pentax screw drive lenses are actually the better choice in many cases (unfortunate, but true nonetheless).


What do you think - does this make sense?

[DSims]

So what can you recommend for photographing running dogs? I am willing to purchase something just for this photo shoot coming up, within my budget ($1,000). Whats most important to me is fast focusing/tracking, 2.8 fast aperture, and sharp high quality images.

I'd say your safest bet is to practice with the FA77 on some dogs ahead of time, and then also order a brand new Sigma 70-200 right away (even though it's a little over your budget at $1250, it's the right one and there are no realistic alternatives).

Or you could get an FA (or F) 135 instead. It's much more responsive in AF than the DA*50-135, and optical performance is comparable. Since I also have the DA*50-135, I almost sold my FA135 until I realized how valuable it was for action. It turns out it's far from redundant (neither is your FA77, of course) and it's small and discreet - people have no idea how long it is so they don't get uncomfortable.


Sigma rendering's not my favorite, but unless it really bothers you I think that's easily the safest way to go. And if you don't like it then you can return it. But at least you'll be prepared - especially if you practice with the FA77 as well. (Plus you'll have one screw drive and one HSM, so you can cover your bases and overcome that controversy .)


Based on my experience with the FA*85, I'd say on the FA77 (which I used to have) you're going to want to shoot around f/3.2 to f/4, but be open to trying the range from approx. f/2.2 to f/5. With the Sigma 70-200, I'd guess that f/3.5 (possibly f/3.2) is good, but could be stopped down to as much as f/5.6 or so.

---

Last edited by DSims; 02-05-2014 at 04:14 PM.

[wpompen]

I'm having a bad day... received the Tamron 70-200 and guess what, the frontfocus is so bad that I can't get it corrected at -10! ... Anyway, coming weekend I'm hoping for some sun so I can test the AF speed on my dogs.
What I can say is that I'm quite impressed so far, AF speed seems fast enough indoors with bad lighting. Sometimes it hunts but so does the Sigma.

[SashasMom]

If you want to see some amazing images of dogs in action check out these images:

She shoots with a Nikon.

portfolio

[DSims]

If you want to see some amazing images of dogs in action check out these images:

She shoots with a Nikon.

portfolio

Nice images! I read her blog entries on her equipment too. I think if I were doing it I'd have the FA*85 on one camera and the FA*24 on the other. You should probably consider trying both the FA77 and FA31.

In any case, have both cameras ready, and put one lens on each (you did say you have two bodies, right?) Don't worry that one's older or focuses slower; it's still worthwhile to do it this way.

[awaldram]

I'd say your safest bet is to practice with the FA77 on some dogs ahead of time, and then also order a brand new Sigma 70-200 right away (even though it's a little over your budget at $1250, it's the right one and there are no realistic alternatives).

Or you could get an FA (or F) 135 instead. It's much more responsive in AF than the DA*50-135, and optical performance is comparable. Since I also have the DA*50-135, I almost sold my FA135 until I realized how valuable it was for action. It turns out it's far from redundant (neither is your FA77, of course) and it's small and discreet - people have no idea how long it is so they don't get uncomfortable.


Sigma rendering's not my favorite, but unless it really bothers you I think that's easily the safest way to go. And if you don't like it then you can return it. But at least you'll be prepared - especially if you practice with the FA77 as well. (Plus you'll have one screw drive and one HSM, so you can cover your bases and overcome that controversy .)


Based on my experience with the FA*85, I'd say on the FA77 (which I used to have) you're going to want to shoot around f/3.2 to f/4, but be open to trying the range from approx. f/2.2 to f/5. With the Sigma 70-200, I'd guess that f/3.5 (possibly f/3.2) is good, but could be stopped down to as much as f/5.6 or so.

Yes I'd generally agree with this recommendation.

You could look at the da*200 but think you may find the fixed focal length limiting for what your trying to achieve.

I'll try and post some f2.8 images so you can compare optical IQ from the Sigma 70-200 EX, Sigma 70-200 EX OS HSM , da*50-135 and da* 300 later.

Though many harp on about AF performance of various lens generally its lack of ability that holds a photographer back not the tool they are using, the slower focusing the lens your using the harder/cleverer you have to work even MF will not stop you getting awesome shots if your skilled/clever.

The issue comes if your making a living from your photography but then your shouldn't be shooting Penttax anyway (no pro support)

This was taken with a k20d (not quick) and Tamron 18-250 (even slower)

[SashasMom]

Nice images! I read her blog entries on her equipment too. I think if I were doing it I'd have the FA*85 on one camera and the FA*24 on the other. You should probably consider trying both the FA77 and FA31.

In any case, have both cameras ready, and put one lens on each (you did say you have two bodies, right?) Don't worry that one's older or focuses slower; it's still worthwhile to do it this way.

I only have 1 body. I know I will get some great shots with the equipment I have. I photographed a hyper yellow lab last year, and images came out great.

[wpompen]

I tried the Tamron 70-200 last saturday with pretty bad weather and I'm very impressed with the speed of the AF, it's close to the Sigma's HSM and accurate.
Personally I find the shots at 2.8 a lot more usable (sharp/crisp instead of really soft) than the Sigma's, the Tamron is a keeper!