Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version 2 Likes Search this Thread
04-12-2014, 08:06 AM   #1
Veteran Member
yorik's Avatar

Join Date: Jan 2012
Location: Scotts Valley, CA
Photos: Gallery
Posts: 991
Fast focusing lenses for K3

Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here.


A recurring criticism I have noticed in various reviews of the K3 is that while Pentax/Ricoh have apparently greatly improved the autofocus system from K5** to K3, the current line-up of Pentax lenses
are not fast-focusing enough to take advantage.

How do (reputedly) faster-focusing lenses from Sigma (e.g., the 70-200 f/2.8 hsm) fair on the K3, if anyone happens to know?

Thanks!

04-12-2014, 08:15 AM   #2
Junior Member




Join Date: Mar 2014
Posts: 35
Something I would definitely like to try with the 120-300 if they ever release it for Pentax.
04-12-2014, 08:23 AM   #3
Site Supporter
Site Supporter
crewl1's Avatar

Join Date: Jul 2010
Location: Los Angeles, CA
Photos: Gallery | Albums
Posts: 9,807
On the K-3 they do very well - I have both the 70-200 OS and Bigma OS and they are both quick.
All screw drive lenses are fast too.
The ones that are slow are the SDM lenses.

I don't shoot Canon or Nikon so have no point of reference.
04-12-2014, 08:29 AM   #4
Veteran Member
yorik's Avatar

Join Date: Jan 2012
Location: Scotts Valley, CA
Photos: Gallery
Posts: 991
Original Poster
In the DPR (gold medal) review of the K3 the main problem that they point to is with AF-C on subjects moving towards or away from the camera... Any experience with these scenarios and the fast Sigma lenses?

Thanks!

04-12-2014, 08:51 AM   #5
Site Supporter
Site Supporter
crewl1's Avatar

Join Date: Jul 2010
Location: Los Angeles, CA
Photos: Gallery | Albums
Posts: 9,807
The AFC tests I have done is with dancers so they are typically moving side to side more than front to back.
I haven't done track and field or bike races to test more rigorously.
04-12-2014, 09:25 AM   #6
Otis Memorial Pentaxian
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 42,007
QuoteOriginally posted by crewl1 Quote
I haven't done track and field or bike races to test more rigorously.
I would view bike races as the ultimate challenge since the action is fast and potential targets are many and scattered over significant depth.


Steve
04-12-2014, 10:12 AM   #7
Veteran Member




Join Date: Jun 2009
Posts: 11,913
QuoteOriginally posted by yorik Quote
the main problem that they point to is with AF-C on subjects moving towards or away from the camera... Any experience with these scenarios and the fast Sigma lenses?
K-3 with the Sigma 70-200 HSM II does very well using AF.C on targets moving towards you. Better than the K-5, in my experience.

Some simple, perhaps not ideal, examples.


Birds on Flickr.

Focus maintained on rider:


Opening rider on Flickr.

Focus maintained on rider as bull charged forwards along the barrier and then pulled sideways away from the barrier:


Yellow chaps 1 on Flickr.


Yellow chaps 5 on Flickr.

Unfortunately action shooting is never just point-and-shoot though. Even D4 and 1Dx sports shooters will miss focus sometimes.

04-12-2014, 10:18 AM   #8
Veteran Member
yorik's Avatar

Join Date: Jan 2012
Location: Scotts Valley, CA
Photos: Gallery
Posts: 991
Original Poster
Thanks to all for the (helpful and informative) answers!
04-12-2014, 11:39 AM   #9
Veteran Member




Join Date: Sep 2009
Location: Southern California
Photos: Gallery | Albums
Posts: 3,236
I do shoot runners. I also shot dancers one time with crewl1, using both his and my equipment. While shooting runners coming toward me is a challenge for the AF system, I found the AF performance was substantially similar shooting dancers indoors in lower light. So we should not discount the importance of AF performance in those scenarios.

I'm sure DPR tried hard on those tests, but it think they missed the boat. Pentax screw drive lenses do the best. The DA*300 comes close to them (but noticeably not as good - it not only seemed slower, but I completely lost focus more often with it than the F*300). No other Pentax SDM lens is even worth considering for fast action. The Sigma 70-200/2.8 OS HSM seemed to do better than the DA*300, and may have even matched the screw drive Pentax primes I use (FA*85, FA135, F*300). I've read the screw drive Tamron 70-200/2.8 now matches the Sigma on the K-3, and it should also come close to it on the K-5 II or IIs (but not the K-5 or older bodies).

The Tamron 17-50 and 28-75 f/2.8 zooms are the best candidates in the shorter range. Pentax primes work here too. But shooting runners coming at you on the FA43 is futile if you want to fill the frame with them, because they're so close by then that you can never get focus before they pass you. So any lens at these focal lengths must be taken with the forward motion mostly stopped - or else be a rather wide group shot.
04-12-2014, 12:01 PM   #10
Veteran Member
yorik's Avatar

Join Date: Jan 2012
Location: Scotts Valley, CA
Photos: Gallery
Posts: 991
Original Poster
Good to know - thanks! It seems that my F 135 might be a good candidate for fast continuous focusing on the K3...
04-12-2014, 12:21 PM   #11
Veteran Member




Join Date: Sep 2009
Location: Southern California
Photos: Gallery | Albums
Posts: 3,236
QuoteOriginally posted by yorik Quote
Good to know - thanks! It seems that my F 135 might be a good candidate for fast continuous focusing on the K3...
Absolutely! You've got one of the best already!

Also, try out the FA77, and please let us know how it fares. I haven't had mine in a while, and I can't seem to get good reports on how well it works for action. In theory it will be good, but I'd really like to hear something definite.



Those focal lengths both work well for various types of action shots. The K-5 with the F135 is already good; the K-3 (or even K-5 IIs) will only improve its AF performance.
04-12-2014, 12:59 PM   #12
Veteran Member
VisualDarkness's Avatar

Join Date: Nov 2011
Location: Uppsala, Sweden
Photos: Gallery
Posts: 4,439
The DA70/2.4 is also blazing. My Sigma 70-200/2.8 HSM II have never been a limiting factor for AF on my K-5, the OS version is supposed to be even quicker.
04-12-2014, 01:02 PM   #13
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 51,594
QuoteOriginally posted by yorik Quote
A recurring criticism I have noticed in various reviews of the K3 is that while Pentax/Ricoh have apparently greatly improved the autofocus system from K5** to K3, the current line-up of Pentax lenses
are not fast-focusing enough to take advantage.

How do (reputedly) faster-focusing lenses from Sigma (e.g., the 70-200 f/2.8 hsm) fair on the K3, if anyone happens to know?

Thanks!
For lenses with built-in motor, the AF speed on the K-3 will be about the same as on other cameras, since the camera has no control over the motor. However, screwdrive lenses are considerably faster. Any DA or FA limited (except for the macro) focuses almost instantly

Fast-focusing SDM lenses that I've tested include the Sigma 17-70mm F2.8-4 "C", Sigma 35mm F1.4 "A", Sigma 70-200mm F2.8 and Pentax 18-135mm F3.5-5.6.

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:
04-12-2014, 01:25 PM   #14
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 40,451
So I seem to have heard (in the above thread) , the Tamron 70-200 with screw drive is now as fast as the Sigma 70-200 HSM? That is awesome news, because just from my own research it seemed that the Tamron was the better lens, but on a k-5, slower focusing, and it's cheaper. If on a K-3 it's as ,fast as the Sigma, that would make it a steal.

I can pick up a Tamron for $649 new... a fraction of the cost of the Sigma.
http://www.ebay.com/itm/NEW-TAMRON-SP-AF-70-200mm-F-2-8-Di-MACRO-LENS-f-PENT...item486498f35c
04-12-2014, 02:47 PM   #15
Veteran Member




Join Date: Sep 2009
Location: Southern California
Photos: Gallery | Albums
Posts: 3,236
QuoteOriginally posted by normhead Quote
So I seem to have heard (in the above thread) , the Tamron 70-200 with screw drive is now as fast as the Sigma 70-200 HSM? That is awesome news, because just from my own research it seemed that the Tamron was the better lens, but on a k-5, slower focusing, and it's cheaper. If on a K-3 it's as ,fast as the Sigma, that would make it a steal.
Another Pentaxian in an earlier thread said that in a direct comparison on the K-3 it was only a tiny bit slower - not enough to matter. And I'd already read other reports that the Tamron AF speed is great now on the K-3, although they hadn't compared it to the Sigma.


My guess is that it's so close that a person's unintentional bias (according to whether or not they're used to hearing the screw drive) could come into play. So I'd say it's easily the better value, and I'd prefer it optically over the Sigma as well.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
dslr, fast focus lens, k-3, k3, lenses, pentax k-3

Similar Threads
Thread Thread Starter Forum Replies Last Post
Fast focusing lens for action shots Hope9811 Troubleshooting and Beginner Help 11 01-14-2014 10:09 AM
fast 50s, other fast lenses, nice bokeh? cream Pentax SLR Lens Discussion 37 10-11-2013 11:55 AM
Fast, fast focusing 30-35mm prime? For dance photography Pheo Pentax SLR Lens Discussion 22 11-02-2012 07:57 AM
For Sale - Sold: LX focusing screen - SA23 - made for FAST lenses! frank Sold Items 2 08-14-2011 03:29 PM
Which focusing screen for fast focusing? Marcoz Pentax Camera and Field Accessories 19 02-13-2009 01:52 AM



All times are GMT -7. The time now is 07:47 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top