[123jippo]

For example Canon allmoust all lenses come with good usm AF motor that is silent, fast, durable and accurate even in dark they hit focus. With Pentax situation is just opposite. Pentax AF is not good really but sometimes u can get very sharp pics when focus is correct but moustly focus is not correct.

But then in also Canon users complain about their AF accurancy...

[magkelly]

I can't speak for the K-5 because I only have a K-x but generally I've found it depends a lot on the lens. The couple of Pentax AF lenses I have seem to do so much better than the non-OEM ones it's not even funny. I think the AF on my K-x is pretty good actually but it also depends upon what lens I put on it and the amount of light, iso setting etc. I don't expect to use a crappy zoom, 100 iso in a half dark room and still get amazing shots. But a decent fast lens, 400, 800 iso maybe, and I might do a lot better, though I prefer to also add some more light if at all possible, of course. I rarely have to bump the iso past that though and even with just the kit lens I do fairly well in not the greatest light. I've shot in a darkened theater with my K-x, no flash, and at 800 with a fast lens and you'd be amazed at how good the shots were. Bad lens and I can be sitting there all day even at 800 iso. I'm told the K-5 is even better. K-30 likely too.

[ihasa]

Does the iso make a difference?

Really, I think Pentax AF is basic but not awful. People are rightly expecting more advanced AF for the higher end models though, and it looks like Pentax are starting to make some strides.

[deadwolfbones]

Really, I think Pentax AF is basic but not awful. People are rightly expecting more advanced AF for the higher end models though, and it looks like Pentax are starting to make some strides.

I'd agree with this.

[fs999]

It depends with which lens...

German magazine Colorfoto made a comprehensive AF test with comparable bodies and with a lot of lenses. And the winner is the K5.

You can find a report and links from Falconeye here.

[snake]

Ive invested alot into pentax over the last year and i hear alot about the slow and unreliable auto focus. Pentax and olympus are the only dslr ive ever used, so my question is is the AF on the K-5 that bad for wildlife compared to canikon?? cheers Travis

I've had my K-5 for a little around 2 months now. I would not rate the AF bad, but simply as "different", which requires some adjusting around it. The main issue is that the AF points are very large and people might not be understanding that the system is locking onto something, but not necessarily what they wanted.

It simply requires adjustment to shooting style and one must understand that AF is also based on the lenses being used. In my case, the FA35 is my primary lens, but also the one that produces the most misses in low light, while my F50 1.7 and M85 f2 (the later using catch in focus) are both superb, though with the M85, if I focus too fast, I get soft focus.

If you're interested, check out this blog entry of mine. The nighttime shots were all done with the FA35. A few of the band are soft or blurry, which is obviously my technique having been flawed and also due to the spontaneous nature of the festival. At least one other showed a soft focus (biased towards the front), but also movement was responsible there. A previous festival excursion in daylight yielded much better results.

I also find my f50 1.7 to produce the highest keeper rate of all my lenses, day or night.

Additionally, I'll submit that the 5DII had a vastly inferior AF system to the K-5, but we see hundreds of thousands, if not, millions of the world's greatest pictures during its cycle, no issues. It's about perception. If it's inferior or not is something someone can decide for themselves by doing some footwork and demoing or renting.

I'm still new to the K-5, but I'm getting better with predicting its behavior.

[andre-mz5]

The Pentax AF is certainly not bad, but until the introduction of the K5 the AF-C was not very usefull. The biggest problem with Pentax AF compared to Canikon is that Pentax does not have "predictive focussing" and that feature will help a lot when you shoot action and sports. The top of the line Canikons are used in sports, but even those camera's may miss sometimes. I've seen a test with an EOS 1d shooting an atlete running towards the camera and not all shots were spot on. Of course you will never see the missed shots, you will always see the best shots in the papers, magazines or forums.

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Last edited by andre-mz5; 07-19-2012 at 02:24 AM. Reason: typo

[Rondec]

I think there are a couple of areas where the Pentax "flagship" cameras are a step behind. First of all, they have significantly fewer auto focus points and these points tend to be fairly good sized, particularly the center point, meaning that the camera may grab onto a contrasty area in front of, or behind where you are shooting. The other thing is what Andre says, that Pentax doesn't have great tracking algorithims. AF-C is now decent in the K5 and K30, but it is a step behind even mid-range cameras like the D7000 and 7D.

I think the other point is that some Pentax lenses are just slow to focus. The DA *55 and 50-135 have pretty slow focus motors and long focus throws and they just don't get there very fast. Fine for portraits, not always so good for action photography.

[snake]

If it makes any difference, this was posted on DPR also and is being treated mostly like a troll.

[dane.dawg]

If it makes any difference, this was posted on DPR also and is being treated mostly like a troll.

If you think im a troll you are mistaken.. I knew when i asked this question most people would take it the wrong way. I live in a small town and never had a chance to test any other system, but am very happy with my widlife photos and pentax in general.

[snake]

If you think im a troll you are mistaken.. I knew when i asked this question most people would take it the wrong way. I live in a small town and never had a chance to test any other system, but am very happy with my widlife photos and pentax in general.

You have the camera, yet ask how it would theoretically work in the application you're supposedly currently using it, rather than trying it out for yourself and answering for yourself. There's nothing more to it than trollbait.

[deadwolfbones]

No, that's not what he's asking. He's asking if other companies' AF systems (ones he hasn't been able to try) are enough of an improvement to make Pentax's AF system look bad in comparison.

He's posted enough wildlife work on this board to know that his Pentax AF system is "good enough" to get some good shots. What he doesn't know is whether the grass really is greener.

[dane.dawg]

Thank you deadwolfbones, that is what I was trying to get at. I am in no way complaining about pentax , I just asked a question about the differences between pentax and canikons AF.

[magkelly]

Of course iso matters when shooting in low light. Try it at 100, 200, and up. Use the same AF lens and watch your results. Sometimes going from say 200 iso to 800 iso can make a huge difference when trying to shoot in semi-darkness. I personally dislike going above about 800 iso. I don't like noise to have to remove with software and anything above 800 iso is usually too noisy for me. But this is a major selling point with Pentax cameras that you can go above that and still take decent pics. I prefer 200, 400 most of the time, but I will go up to 800 if need to. Again though it comes down to what lenses you put on your camera. Also what other settings you use.

My Tamrons, all 3 of them, search like crazy whenever I try to use them in low light. Same settings, I put my kit or the one other AF Pentax lens I have on and I don't have near as much trouble. That tells me it's not the K-x so much as it's the lenses. I can actually get shots with my kit lens that I just cannot get with the Tamrons. My fastest lens though is actually a MF Pentax lens. If I am shooting in really, really low light it's 800 iso and that lens. My camera can't do everything for me and I don't expect it to. This is why they have manual mode and MF on the camera. Sometimes it's just better to do it yourself. AF is a nice thing to have. Lately I rely on it a lot more. My eyes are giving me trouble, but no camera on the planet can do everything for you in every lighting situation.

All cameras will potentially stumble in very low light. That's a basic photography thing. Low light=much tougher shots. A good, fast lens will help, so will a slightly higher iso, but expecting any camera to get 100% perfect shots, AF or not, in almost no light is asking a lot. That kind of scenario usually takes some real work on the part of the photographer. Aperture, ISO, shutter speed, lens speed, amount of available light they all will impact your end result.

One thing that also helps with low light AF shots I've found is the flashlight trick. Aiming a very bright small flashlight in the direction of the object you're trying to shoot can help your AF lock on to it's target. Once you get it, quickly switch the camera to MF to lock that focus in and shoot. I learned that one from shooting outside at night with one of my teachers but it works indoors too. I always carry one of those small LED flashlights in my pocket when I am shooting either way. Also a couple of little round LED lights with hooks for adding light to impromptu close up shots. They can come in real handy. You don't have enough light? Can't set up a bunch of studio lights? You can still make light yourself sometimes.You just have to hit the hardware store and think outside the box.

[rawr]

Same settings, I put my kit or the one other AF Pentax lens I have on and I don't have near as much trouble.

This is something I have noticed too.

Even the DAL 18-55 kit on the K-x had some sort of magic going on where it could get great shots that my faster and optically better Tamron 17-50 just couldn't in the same lighting, and it has something to do with both the AF and the exposure metering of the Pentax lenses and how they interact with the camera firmware.

People have expressed scepticism about this issue [Pentax camera's working better with Pentax lenses than 3rd party lenses] on these forums, but I've seen this occur a lot in my shooting.