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10-22-2010, 10:45 AM   #106
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QuoteOriginally posted by johnmflores Quote
Dgales - your son runs with such style! it's like a (relatively) high speed strut LOL! thx for sharing
You're welcome

I caught a sequence yesterday when he was running during warm-ups for soccer practice and at one point his run went from a normal run to a side step to strut all in one smooth motion.... it was pretty entertaining

10-22-2010, 10:49 AM   #107
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QuoteOriginally posted by Eruditass Quote
AF-S?
No AFC
10-22-2010, 10:53 AM   #108
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QuoteOriginally posted by jake14mw Quote
Thanks telfish, Those are tough to judge because the dog is long, and it's tough to judge the center of the photos. At first glance, they look like they have the typical lag in focusing that we are used to with AF-C, but it might be that the centerpoint is actually on the dog's back, meaning that the camera is actually keeping up.
I'll get a shorter dog
10-22-2010, 12:54 PM   #109
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QuoteOriginally posted by Raven Quote
So far no one seriously tested AF-C even in normal conditions.
That would be a real-life condition (low light, wide open need) too, but I get your point and it's true.
Waiting for some brave souls.

JP

10-22-2010, 01:12 PM   #110
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QuoteOriginally posted by garyk Quote
I think Pentax will make slow progress with af-c but if you ask if pentax will ever be in the same ball park with nikon or canon????? Not in the next few years in my opionion. Pentax makes a great static camera. Af is fine and accurate. Picture quality is good. 99.9 % of my shooting is static. And i think true of most folks.
Starting this post wasn't meant to make comparisons with other brands. It wans't meant to claim that the K5 would equate the AF of other brands.
The title of the thread is self-explanatory.

Reguardless I shoot pentax and I am at a raptor migration. I am soooting pentax and sigma 500mm f4.5 and 300mm f2.8. I need some help here. I really did not know how far behind Pentax was until i saw these guys and gals shoot bif. It is really amazing what canon and nikon have done.
Here is a link to a few shots of bif.. Not one in focus and sharp. It is a huge mistake to buy Pentax if you use af for af-c. But for static objects I think just fine.

With that said, I saw the pictures you are mentioning (first link) from which you claim none of them being in focus. True enough, they are not.
I tried looking at the EXIF data ... couldn't get them there. What camera was used? K7? K20D?

Chumphon ( a few birds ) Photo Gallery by Gary at pbase.com

Pentax k-x really shines as will the k-5 and k-r i think. And in my opinion just as good as the top two.
Check out these bird shots with the Sigma 500 and 300 and the k-x. All shot fast and all sharp.
Indeed, they are much better than those in that first link.Flickr: gary1844's Photostream

Once you leard the system and rule out the k-7. Which is the biggest stinker (underlined and bolded by me, jpzk)i have ever used.The Pentax k-x shoots professionally. The k-x at 500 dollars bests the images of cameras many times the price. In my opinion.
No need for bashing the K7 here, we've had plenty of that on this forum over the past few months. There are other threads with the "same old story" somewhere, not here though.
If you believe that the Kx bests cameras at twice the price, good for you and I hope you will enjoy it for a long time.

I am extremly serious about IQ. The glass makes the photos. the camera is just there to capture it. but bif and af is huge. Other than in my opionion any dslr will work. all dslrs on the market are very good compared to a few years ago.
I don't quite get what exactly you are getting at!
Do you have any K5 AF-C shots to show here?


Best of luck in your quest to find the best camera for acute AF-C IQ!

Yours,

JP
10-22-2010, 01:27 PM   #111
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QuoteOriginally posted by telfish Quote
I'll get a shorter dog
Get a Chihuahua !!

Back to reality: those series of shots with AF-C are actually not bad at all. I am not commenting on the overall IQ of each image, rather about the precision of the AF.

Granted, the dog is moving in "doggy style" (pardon the pun not intended ) with a bumpy trot, head moving up and down a little with each pace ... normal.

Second thing is: you do mention being not so experienced with this sort of photography and that is great because if you can achieve a good keeper rate, I am more than pleased with the results.

You used wide open aperture (f2.8) and that's painful enough for any system, whether it is Pentax or Canikon, or else.

I want to thank you for all of the shots you've been sharing here; very much appreciated.

JP
10-22-2010, 01:55 PM   #112
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QuoteOriginally posted by jpzk Quote
Get a Chihuahua !!

Back to reality: those series of shots with AF-C are actually not bad at all. I am not commenting on the overall IQ of each image, rather about the precision of the AF.

Granted, the dog is moving in "doggy style" (pardon the pun not intended ) with a bumpy trot, head moving up and down a little with each pace ... normal.

Second thing is: you do mention being not so experienced with this sort of photography and that is great because if you can achieve a good keeper rate, I am more than pleased with the results.

You used wide open aperture (f2.8) and that's painful enough for any system, whether it is Pentax or Canikon, or else.

I want to thank you for all of the shots you've been sharing here; very much appreciated.

JP

There is very little contrast in a black Lab. So if the AFC can keep reasonable track I am pretty happy. I am busy today and tommorow (work calls) but Sunday if the weather is decent I will take some shots of BIF or ducks a swimming and see how they come out.

My efforts are pretty amateur so if I can get a reasonable result anyone can. I am used to things staying put and just witing to be shot
10-22-2010, 02:28 PM   #113
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QuoteOriginally posted by telfish Quote
There is very little contrast in a black Lab. So if the AFC can keep reasonable track I am pretty happy. I am busy today and tommorow (work calls) but Sunday if the weather is decent I will take some shots of BIF or ducks a swimming and see how they come out.

My efforts are pretty amateur so if I can get a reasonable result anyone can. I am used to things staying put and just witing to be shot
That would be a great time to get some poor light conditions for the AF!

Have a great weekend and thanks again for your efforts!

Cheers.

JP

10-22-2010, 03:00 PM   #114
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QuoteOriginally posted by garyk Quote
Check out these bird shots with the Sigma 500 and 300 and the k-x.
Very impressive images on your flickr garyk.
10-22-2010, 04:50 PM   #115
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QuoteOriginally posted by telfish Quote
last in this series. I am not an experienced shooter of moving objects so some oof could be my fault
Thanks for this series.

This isn't bad and the K20D would have struggled at this task, I believe.

However, this isn't yet on par with the best running dog sequences I've seen in the net (I tried to find the series now but so far, no luck ). The camera probably could do better in an ideal situation.

What I did find though is this chart:



[source (c) Understanding Camera Autofocus]

It shows what I meant: One has to consider speed and distance and focal length (chart is for 300mm). Probably, it's just the magnification change speed which matters.

Of course, the plot must be idealistic (although the nuumbers are meant to be serious) and the distance scale to the right must read [8 . 10 ... 20 30 40 50].
10-24-2010, 03:04 PM   #116
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QuoteOriginally posted by falconeye Quote
Bert, the shots were cropped from 300mm which is my longest lens to date.

Slightly offtopic, but I am looking into my options indeed and the Sigma 500/4.5 EX seems to one of the few options whch may still be usable free hand and has cropping potential. However, so far I couldn't find out how the AF works with the Sigma 1.4x TC and how much of a cropping potential the Sigma 500/4.5 EX really has. Esp. with 16MP APSC and 1.4x which resolve 150 lp/mm.
I have a K-x , Sigma 500mm/4.5 & 1.4x TC & it does AF (the Sigma website says otherwise).
10-24-2010, 03:37 PM   #117
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QuoteOriginally posted by PMunks Quote
I have a K-x , Sigma 500mm/4.5 & 1.4x TC & it does AF (the Sigma website says otherwise).
I think the Sigma website says otherwise because on Canon and with the Sigma TC, this is what happens. However, even on Canon, it seems you can make the Tamron AF work if you tape a few contacts.
10-24-2010, 03:49 PM   #118
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QuoteOriginally posted by falconeye Quote
Thanks for this series.

This isn't bad and the K20D would have struggled at this task, I believe.

However, this isn't yet on par with the best running dog sequences I've seen in the net (I tried to find the series now but so far, no luck ). The camera probably could do better in an ideal situation.

What I did find though is this chart:



[source (c) Understanding Camera Autofocus]

It shows what I meant: One has to consider speed and distance and focal length (chart is for 300mm). Probably, it's just the magnification change speed which matters.

Of course, the plot must be idealistic (although the nuumbers are meant to be serious) and the distance scale to the right must read [8 . 10 ... 20 30 40 50].
I need to look into getting me a CANON!. Pentax just sucks all around

Thank`s for that CANON AFC graph.

And, no I did not read all of the posts before replying.
10-30-2010, 02:11 PM   #119
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As requested by jpzk, here's a random "real life" test I did yesterday under absolutely terrible light conditions. They aren't much to look at, but they do serve to make a point. I'll just quote myself from the other thread to do the explaining:

QuoteQuote:
I just did an impromptu, real life test of the K-5 AF. I was busy shooting some scenes around campus, when a random guy doing tricks on his bike asked me to shoot him.

Well, this was half an hour after sunset in a rapidly darkening square, so I had my doubts about how well this was going to work. It was dark enough that even at ISO 6400 and aperture wide open (f/4, this was with the 55-300), shutter priority wouldn't let me go faster than 1/40.

Well, as expected, most of the pictures were a loss due to motion blur. 1/40 is just way too slow for a target moving at 7-8 mph right past me. But surprisingly even in the darkness, AF kept focus dead on all the way, even with me zooming while shooting. From the couple of sharp photos, and a bit of examining the blurred ones, I can tell that most of them are more or less right on in focus.

I'm a noob when it comes to motion tracking and action shooting, but this was definitely a pleasant surprise. I've lost more than a couple photos on my K-x due to it deciding to hunt at the worst times.
Keep in mind that this scene was quite a bit darker than these photos would lead you to believe, so all of them suffer from some motion blur (worsened by my amateur motion tracking technique). I thought about dialing down some EV compensation (which would make it look more like it did to my eyes) to bump up the speed, but he decided to call it quits then. But this is about AF-C under terrible lighting, so that's just a side note.







Here's a crop from one shot that was a total loss due to motion blur. Despite that, this crop shows that the camera still kept good focus.


Last edited by Cannikin; 10-30-2010 at 02:24 PM.
10-30-2010, 04:05 PM   #120
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QuoteOriginally posted by Cannikin Quote
absolutely terrible light conditions.
FWIW, the light is about EV 3-4.

According to my tests, the K-7 AF slows down somewhere between EV 2 and 5 and fails around EV 0-1.
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