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03-01-2008, 04:14 PM   #76
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I tested it.

My K20D's AF limit is at about 1EV (using a f/2.8 lens). Higher, it focusses quite reliably (<2s), at 1EV, it focusses but sometimes does some hunting beforehand. Below, it may fail to focus altogether. This seems to be in line with the findings in the graph presented for the K10D earlier in this thread.

From what I've seen, the focus seemed to be correct when the K20D said it were in focus. This is important for me if I shall trust the AF at all. Form what I've read, other makes may focus faster but less reliably.

Using f/1.4 glass didn't seem to improve much (what's the theory here: 2 EVs better?). But I cannot tell for sure because my 1.4 glass is MF only, so I only could observe the focus indicator.

For EV, refer to Exposure value - Wikipedia, the free encyclopedia (0EV is 1s at f/1.0 at ISO100)

With 2.8 glass and ISO1600, 1EV is 1/4s (about the limit with SR). So, with 2.8 glass, the AF seems to fail at the point where extra light or a tripod would be needed anyway.

What's about 1.4 glass? What's about the K10D here?

03-01-2008, 04:26 PM   #77
Busiko
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QuoteOriginally posted by miriya Quote
*ist
...K10D
...
K20D
....

Pentax using same SAFOX VIII AF module about 5 years!

Why not upgrade AF sensor?

Is there any problem of Pentax AF module?

Is Pentax can produce their own AF module?

Is there any good news about new AF module?

or.. K20Ds or K30D, with SAFOX VIII 7 year anivarsary?

Pentax is working on a new AF system using Pattern recognition and Tracking methods. We hope that this new system will solve all the issues that people insist on. Of course that should be available on a new body that will come out eventually.:ugh: Why not!
Regards
03-01-2008, 05:06 PM   #78
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Back to the sports lens issue...very, very, very few of the sports mondo teles are 1200's or frightening sized zooms. The game is primarily 600/4, 500/4.5 or 500/4, and 400/2.8. It's as rare to see a 1200mm in the end zone at the super bowl as it is to see a Pentax. And until recently, Pentax had the previously mentioned killer zoom and a very useful 600/4 so, as usual, glass isn't the slam on Pentax, it's sports style AF and sports style FPS where Pentax lags.
It will be interesting to see how long it takes for Pentax to get back into the mondo tele game--zoom or prime. Now that there is a bit of pro in the newer bodies, there is a buying group of people ready for big glass from Pentax. Coupled with a more capable AF body, Pentax could turn up in a super bowl end zone someday in the foreseeable future.
I'm guessing that we'll see something more like a 400/4 than anything bigger or faster?
03-03-2008, 10:00 AM   #79
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QuoteOriginally posted by falconeye Quote
I tested it.

My K20D's AF limit is at about 1EV (using a f/2.8 lens). Higher, it focusses quite reliably (<2s), at 1EV, it focusses but sometimes does some hunting beforehand. Below, it may fail to focus altogether. This seems to be in line with the findings in the graph presented for the K10D earlier in this thread.

From what I've seen, the focus seemed to be correct when the K20D said it were in focus. This is important for me if I shall trust the AF at all. Form what I've read, other makes may focus faster but less reliably.

Using f/1.4 glass didn't seem to improve much (what's the theory here: 2 EVs better?). But I cannot tell for sure because my 1.4 glass is MF only, so I only could observe the focus indicator.

For EV, refer to Exposure value - Wikipedia, the free encyclopedia (0EV is 1s at f/1.0 at ISO100)

With 2.8 glass and ISO1600, 1EV is 1/4s (about the limit with SR). So, with 2.8 glass, the AF seems to fail at the point where extra light or a tripod would be needed anyway.

What's about 1.4 glass? What's about the K10D here?
Can I ask how you metered for your light. I used a dedicated light meter to determin my K20D's limit to be just like the manual -1EV. I also measured it below 2 seconds. from the moment of pressing to focus it would consistently avarage around one and a half. This is in a Situation that the K10D did not focus consistently or accuratly.

The reason I say this is because camera metering is hardly ever accurate at this level. It could have been the case that you were shooting at EV-1 but simply did not know it.

03-03-2008, 10:31 AM   #80
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QuoteOriginally posted by benjikan Quote
In using the K20D, I find that the focus comes in to place more accurately and quickly than did the K10D. There is not the BF and FF issues that existed before. Pentax improved the Auto Focus via the software. The biggest problem has been in the marketing of the AF. They should have called the improvements Safox lX. If they had done that there would NOT be the complaints we are now getting. I find the new AF has noticeable improvements over the K10D and I cannot understand where these complaints are coming from, as ninety percent of those complaining haven't even handled the camera yet. That is absurd.

Ben
Spot on.
Tried out the K20D with a K10D at the Pentax agent's offices here in Singapore today. Did test shots with the new DA*200, my own DFA 100mm macro, FA77 and FA 20-35mm.

There is certainly a noticeable improvement in focusing speed and accuracy with the K20D over the K10D. The lens used also has a bearing on the AF accuracy and speed. With the DA*200, the focusing was super silent and fast whereas with the DFA 100, there were times the AF took time to lock due to the long focus throw. I have no doubt the K20D/DA*200 combo is more than capable for fast action shooting.

One thing I will say is that those who think the AF between the K10D and K20D are somewhat the same are off the mark. My suggestion is for you to try it out yourself. To me, the more accurate WB, ISO performance and image quality alone makes the K20D a worthy successor to the K10D.


K20D DFA 100mm f/2.8 Macro
03-03-2008, 11:39 AM   #81
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What about the new "trap focus" thing ? Where is this activated in the menu ? Does it work only with AF-C ? Someone did a test with the "trap focus" deactivated and then activated ? How is it the accuracy and speed compared ?
03-03-2008, 07:36 PM   #82
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Perhaps some of us early K20D adopters should write to editors at PopPhoto or ask Pentax to ask them clarify the following:

"Pentax openly admits that the K20D AF system is identical to the AF system on K10D with no claims for speed or sensitivity improvements."

Looks like a miscommunication if Pentax indeed told PopPhoto the above. Or perhaps by saying identical, they're only talking about the AF sensor hardware being the same, not including firmware improvements. But if that's the case I'd agree with Ben that it's a marketing issue.

Peter

Last edited by Peter Fang; 03-03-2008 at 07:46 PM.
03-03-2008, 07:59 PM   #83
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QuoteOriginally posted by Peter Fang Quote
Perhaps some of us early K20D adopters should write to editors at PopPhoto or ask Pentax to ask them clarify the following:

"Pentax openly admits that the K20D AF system is identical to the AF system on K10D with no claims for speed or sensitivity improvements."

Looks like a miscommunication if Pentax indeed told PopPhoto the above. Or perhaps by saying identical, they're only talking about the AF sensor hardware being the same, not including firmware improvements. But if that's the case I'd agree with Ben that it's a marketing issue.

Peter
Why oh why would anyone believe a single word uttered in that useless rag?

03-04-2008, 05:30 AM   #84
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QuoteOriginally posted by Steelski Quote
Can I ask how you metered for your light.
You are right, I trusted the in-camera metering. However, because the subject's contrast comes into play heavily as well, I considered my test being non-scientific anyway Your findings seem to be more credible than mine.
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