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09-11-2007, 07:22 PM   #31
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With motorsports, you can NOT use AF on a pentax if the car is coming twards you.

As much as I despise the pentax AF system (and love the rest of the camera), it is not its lack of focusing speed.

It is the lack of predictive focus. Even if it locks on to the front bumper when the shutter trips, in the time that the mirror has come up, the car is already past your focus point. If you want the rear bumper in focus, it works great. Not sure who would want that though.

As a previous poster mentioned, you need to revert to zone/manual focus for those shots. If the next pentax does not have predictive AF, I will buy a canon for my motorsports shots/backup camera. It would be a shame to do so, and I hope I do not have to.

09-11-2007, 07:58 PM   #32
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You don't need to get a 40D to reap the better AF systems on a Canon camera. Their low end is mighty impressive in that regard.

I know this is not sports, but here are some examples of a series of photos I could not have gotten with my Pentax K10D. I was photographing a Tug Boat race event out in the St. Mary's river, when I spied these fast flying gulls fighting for some food about 150 yards away. I was using my 20D and the Bigma hand held. This was in Single AF Mode and the camera was in program mode. The system was so responsive, that I was able to take this series in a matter of 3 seconds.







09-11-2007, 08:08 PM   #33
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QuoteOriginally posted by Mr Hyde Quote
Why not trying bumping the ISO up to 400 and narrowing the f-stop to f/11 to increase DOF?
I have gone up to f/8 to increase DOF, but I really want to keep the background as blurred as possible. I'd prefer to shoot at f/4, but the focus is even more of a problem wide open.
09-11-2007, 09:02 PM   #34
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Faster AF?

Have you been able to determine any difference between your Sigma lens and your DA 50-135 for AF speed? I would think the SDM should make it quicker. No?

09-12-2007, 03:32 AM   #35
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QuoteOriginally posted by SloPhoto Quote
With motorsports, you can NOT use AF on a pentax if the car is coming twards you.

As much as I despise the pentax AF system (and love the rest of the camera), it is not its lack of focusing speed.

It is the lack of predictive focus. Even if it locks on to the front bumper when the shutter trips, in the time that the mirror has come up, the car is already past your focus point. If you want the rear bumper in focus, it works great. Not sure who would want that though.

As a previous poster mentioned, you need to revert to zone/manual focus for those shots. If the next pentax does not have predictive AF, I will buy a canon for my motorsports shots/backup camera. It would be a shame to do so, and I hope I do not have to.
In a recent event I was getting shots like this all day.

http://i.pbase.com/o6/89/257389/1/80885621.JN5VyWrs.IMGP2341postsmall.jpg

And thats a heavy crop of a shot taken with a 400mm lens of a car travelling at at least 80mph. Out of several hundred shots I maybe got 20% that were not well focused which is acceptable for me.

OK this is at F8 but the lens only goes out to F5.6 and gets PF wide open. I get equally sharp results with a cheapo Tamron 70-300.
09-12-2007, 03:41 AM   #36
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QuoteOriginally posted by GaryML Quote
I am beginning to think that it may be the Sigma lens. I will explore this further at the next game.

My son's team is 9 and 10 year olds, and the field is much larger than the 5 year olds on the "micro-soccer" fields as they call them here.

Here's an example of the issue. This was shot 2 weeks ago with the Sigma lens at 180mm, 1/500 sec at f/5.6, ISO 100 (no tele-converter), with the AF set to AF-C and allowing the camera to select the AF point. I'm trying to get the kids in the center in focus: that's my son in the blue jersey kicking the ball through the legs of the kid in the silver jersey. Notice that the kid on the left is in perfect focus, but the ones in the center (and on the center red AF square as selected) are not in sharp focus because they are moving towards the camera. The exact focus plane can be seen more clearly in the full size image. I think this shot isn't bad, but I would really like it razor sharp. (There is a bit of motion blur due to the slower shutter speed, so that is partly to blame as well.)
Actually you have three kids all running in different directions. Thats a tough one.
09-12-2007, 05:40 AM   #37
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QuoteOriginally posted by SloPhoto Quote
With motorsports, you can NOT use AF on a pentax if the car is coming towards you.
I find with AF.C if you tap the shutter button to make it refresh its focus you can shoot oncoming things.

Perhaps I have a particularly good K10D and a sharp example of the Bigma, but I have very few problems shooting anything. Motorsports is something I do a LOT of and don't find the AF system a hinderance. It makes you work a little harder, but the K10D is a LOT better than my old *istDL!

As for soccer I shot 7 matches on Saturday, 2 under-16's, 2 under-14's and 3 under-10's. On full size and half size fields and had next to no problems.
09-12-2007, 06:29 AM   #38
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QuoteOriginally posted by Lee Quote
Have you been able to determine any difference between your Sigma lens and your DA 50-135 for AF speed? I would think the SDM should make it quicker. No?
When I received the DA* 50-135mm I compared it to my FA 77mm Limited in AF speed in a few informal tests. I believe the 50-135 is faster with less hunting, but the 77mm is known for it's slow AF.

I haven't compared the 50-135 with the Sigma 100-300 directly because I use the two lenses for different purposes. I will bring the DA*50-135 to the next game on Saturday for some test shots. The 50-135mm is too short to use for this application, but it will give me an idea of whether a future SDM lens will do a better job.

09-12-2007, 06:39 AM   #39
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QuoteOriginally posted by blwnhr Quote
I find with AF.C if you tap the shutter button to make it refresh its focus you can shoot oncoming things.

Perhaps I have a particularly good K10D and a sharp example of the Bigma, but I have very few problems shooting anything. Motorsports is something I do a LOT of and don't find the AF system a hinderance. It makes you work a little harder, but the K10D is a LOT better than my old *istDL!

As for soccer I shot 7 matches on Saturday, 2 under-16's, 2 under-14's and 3 under-10's. On full size and half size fields and had next to no problems.
I do use the shutter button to trigger the AF in AF-C.

The DL was my first digital Pentax and it was a good little camera. I upgraded to the K10D about 7 months ago for a lot of reasons, including better AF speed. The K10D has noticeably faster AF-perhaps twice as fast.

Are you using the Bigma for the soccer photos? Do you get accurate focus with AF-C using that lens?
09-12-2007, 09:32 AM   #40
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QuoteOriginally posted by regken Quote
Gary,

As big a fanboy as I am for Pentax I don't think I would recommend their system for this type of shooting. Nor would I recommend any of the other systems unless you are willing to jump all the way up to the new Nikon D300. This is not an area I know a great deal about but my research seems to indicate there are two separate issues here. The first being technique. If you listen to a cranky old codger like jfdavis58 that frequents this forum on a regular basis I'm sure he would tell you something like shooting sports is hard to learn and he can do it with a spotmatic just as easily as he can with the latest greatest $10,000 Canon. There is a great deal of truth in that, it take a lot of practice.

However, for us non professionals that need as much help as we can get equipment does play a roll in our success or lack thereof. From the reading I've done it appears the Canons and Nikons are slightly better than the Pentax but I really have my doubts if there is that much difference in AF speed and accuracy unless you reach into the top end models. The Nikon D300 just might be a different animal. The specs indicate it will be capable of giving you what you want. IMO if I were you I'd keep on working on your skills until the D300 is available.

Regards,

Ken
Interesting specs - 60 fps for still images!! - News - CASIO
09-12-2007, 09:34 AM   #41
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QuoteOriginally posted by GaryML Quote
I do use the shutter button to trigger the AF in AF-C.

The DL was my first digital Pentax and it was a good little camera. I upgraded to the K10D about 7 months ago for a lot of reasons, including better AF speed. The K10D has noticeably faster AF-perhaps twice as fast.

Are you using the Bigma for the soccer photos? Do you get accurate focus with AF-C using that lens?
Can't see the point in pressing the shutter button to "trigger" the AF in AF-C. That's the point of AF-C, AF is always on, as soon as you move the camera or the object moves the focus is corrected. Taking your finger off the button and pressing it again only makes it even slower. Right?
09-12-2007, 10:37 AM   #42
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QuoteOriginally posted by SloPhoto Quote
With motorsports, you can NOT use AF on a pentax if the car is coming twards you.

As much as I despise the pentax AF system (and love the rest of the camera), it is not its lack of focusing speed.

It is the lack of predictive focus. Even if it locks on to the front bumper when the shutter trips, in the time that the mirror has come up, the car is already past your focus point. If you want the rear bumper in focus, it works great. Not sure who would want that though.

As a previous poster mentioned, you need to revert to zone/manual focus for those shots. If the next pentax does not have predictive AF, I will buy a canon for my motorsports shots/backup camera. It would be a shame to do so, and I hope I do not have to.
WHOA! Easy there dude! Never say never! I would say you don't wanna' use the continuous mode, (sometimes you get lucky, sometimes you don't), but AF-S seems to work alright most of the time. I agree the Pentax does not have equal focusing to the Canon or Nikon brands, but most everyone knows that when they make the purchase. I am willing to forego that single issue as I love everything else about the camera, and I know I can compensate, most of the time. That being said, I do occasionally miss a great shot because the K10 couldn't focus quite fast enough.

As has been pointed out there are things you can do to help alleviate the problem. Bump your F stop up, for one. even f8 is often enough to bring your whole subject tack sharp when using AF-C.

1/500 f8 iso160 fill flash AF-C - K10, Sigma 100-300 4.0 EX DG @ 150
09-12-2007, 12:38 PM   #43
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Two things.. Make sure you're using AF-C (Auto-Focus-Constant) and USE Shake Reduction. I don't care what the manual says. 300mm on a tripod with fast shutter speeds works great with SR ON. My personal experience.
09-12-2007, 01:16 PM   #44
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QuoteOriginally posted by ricardobeat Quote
Can't see the point in pressing the shutter button to "trigger" the AF in AF-C. That's the point of AF-C, AF is always on, as soon as you move the camera or the object moves the focus is corrected. Taking your finger off the button and pressing it again only makes it even slower. Right?
I partially depress the shutter to activate the AF-C when it looks like there will be a good shot. I release the shutter button if the action has moved away or there is a pause so I'm not just draining the battery and wearing out the AF mechanism when nothing is happening. There is almost no delay if I give the AF a few seconds of rest. The only significant delay is if the camera goes into sleep mode after a long pause. That has caught me a few times!
09-12-2007, 01:19 PM   #45
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I would definitely put myself at the novice level, but shoot a fair amount of soccer, softball, and Take Kwon Doe.

In bright daylight, I find that shooting at 1/750 to 1/1000 has given me pretty clear pictures, including the softball or soccer ball after being hit, thrown, kicked, or whatever. Evening soccer games under lights is a challenge due to less light, as is gym TKD events.

A related issue for me is the challenge/balance in zooming in on individual people/faces versus zooming out a bit to capture the ball action at the same time.

I generally use a Sigma 100-300mm in these situations...
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