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11-23-2013, 12:39 PM   #46
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QuoteOriginally posted by philbaum Quote
This review also mentions that the K3 27 AF points cover a larger area than those arrayed in the D7100, and also include 25 cross sensors on the K3, 10 more than the 15 of the D7100. With these kinds of related data, the K3's tracking may very well exceed that of the D7100. Of course the lenses chosen for such testing can affect the final results, but if that is the case, thats not a deficit of the camera itself.
The K-3 has more cross type points than any current Nikon. This is just a spec on paper, though. A practical comparison is necessary to judge the relative performance of the two cameras. When using the two side-by-side for tracking, you'll see that in practice, specs don't say much about the behavior and implementation of either AF system.


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11-23-2013, 12:42 PM   #47
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QuoteOriginally posted by philbaum Quote
Ok, i accept what you're saying about the AF points, but does the D610's AF system benefit from the more powerful processing unit of the ff camera? Or does it have its own aps system processor carried over? (BTW, its interesting to me how mfr carry over "nuts and bolts" from previous designs. saves a lot of time and expense where it works)
That's a good question. The D600 is using Expeed 3 instead of 2 on the D7000; does that make it faster? Are there other differences? How about the D7100?
I guess the only way to know is to measure it; there are too many variables.
11-23-2013, 05:29 PM   #48
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QuoteOriginally posted by philbaum Quote
Is change good or bad - don't know - it just is.
Yes it 'just is', but it can also be good bad or indifferent. Whether it's good or bad depends on the judgement guiding its application. Too bad when questioning the latter, one can be accused of questioning change itself. Sometimes the technology outstrips the wisdom of its application, and that wisdom should always be open to discussion.
11-23-2013, 05:46 PM   #49
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QuoteOriginally posted by arnold Quote
Yes it 'just is', but it can also be good bad or indifferent. Whether it's good or bad depends on the judgement guiding its application. Too bad when questioning the latter, one can be accused of questioning change itself. Sometimes the technology outstrips the wisdom of its application, and that wisdom should always be open to discussion.
There is nothing wrong with autofocus - I use it all the time when I have a lens on that supports it. Even with quick shift manual focus can be difficult with AF lenses because of the limited angular travel of the focus ring and the necessary lack of damping.

What puzzles me, and I haven't really looked into it in any detail, is whether there is a fundamental flaw with the phase detect focus method, in that the focus points have to be at the frame centre, or whether it is just the Pentax implementation that has this shortcoming.

11-24-2013, 03:06 PM   #50
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QuoteOriginally posted by Adam Quote
The K-3 has more cross type points than any current Nikon. This is just a spec on paper, though. A practical comparison is necessary to judge the relative performance of the two cameras. When using the two side-by-side for tracking, you'll see that in practice, specs don't say much about the behavior and implementation of either AF system.
Yep, i agree with you - just specs on paper. But its a good trend by Ricoh, and whether its this year or some future year, i think Pentax models will be very competitive with regard to AF tracking. Ricoh has shown the patience to win market share in business copiers, so they definitely know how to go about doing it - one patient step at a time.

QuoteOriginally posted by kh1234567890 Quote
What puzzles me, and I haven't really looked into it in any detail, is whether there is a fundamental flaw with the phase detect focus method, in that the focus points have to be at the frame centre, or whether it is just the Pentax implementation that has this shortcoming.
I dont know about the really high end cameras, like D4, but my Sony Nex 6, the D600, and K3 of course have all concentrated AF detectors in the center. You can pick a specific af point to left or right of center, etc, but they are not out on the fringes. I think that makes sense most of the time. Most of the time for action photography, the photog is trying desperately to capture the action and is targeting the moving subject in the center, or as close to center as possible. If the subject is moving towards the photog, left to right or right to left, it does no good for the camera to adjust focus for something on the edge of the frame and then will be out of the frame (but focused out of frame :-)).

Now one could make the case that af points on the edge of the frame would catch something moving into the frame, but they are not nearly as useful as something in the center area which can be used for both objects moving in and moving out of the frame. Also some Nikon cameras were criticized a few years back for not having enough processing power to do all the tracking applications, might be the old D300 that i read about. The point being that AF tracking must take a ton of processing capability. Given that fact, then it makes sense to put most af points closer to the center area and not out on the edges of the frame where the payback is less.

Of course, your example shows why the above strategy is not a 100% solution. But life is often a series of compromises, IMO.
11-24-2013, 04:03 PM   #51
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I prefer both

QuoteOriginally posted by kh1234567890 Quote
Manual focus appears to be a 'lost art'. I can't get my head round why is everyone raving about the K-3 having 27 or whatever focus points when they are still crammed into the centre of the frame. Does everyone just take boring shots with the main subject at dead centre ?

On a snap like this (M50 f1.4 wide open on an ancient K-7) any current Pentax autofocus would have failed miserably
I agree with you quite hardily. That is a nice capture BTW. While probably 70% plus of my photography is MF and that includes BIF, at times I like to use AF. But when needed, I prefer it to actually work. I guess between my K-5. Fuji X-E1 and Sigmas, you would hope I like MF. The K-3 may change my habits if it lives up to the hype....
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