[thibs]

I have tried it fot two days before upgrading to v1.3, since then, I also tried the lens on my Ds and my Z1P.

I find the AF speed to be about the same with/without SDM so I don't think the relatively unimpressive AF speed is related to SDM.

It's more of a design/gearing issue IMO.

Thank you for the clarification. This is not my experience at all but as I said I played with it in a shop and that's it, not very meaningfull but I was surprised.

[Ishpuini]

I have tried it fot two days before upgrading to v1.3, since then, I also tried the lens on my Ds and my Z1P.

I find the AF speed to be about the same with/without SDM so I don't think the relatively unimpressive AF speed is related to SDM.

It's more of a design/gearing issue IMO.

Don't get me wrong though, I am using it extensively now and the lens won't go anywhere as it is really an excellent lens, the AF speed "issue" doesn't really show up until you want to focus quicly from far to near. But if you have to do this, it take about 1s to go from 1m+ to 10m+ which is not very good, even by Pentax standards (which are pretty good IMHO).

My FA 135 take approximately half of that time to go from 0,7m to infinity on the K10 and more generally, all my lenses are faster to travel from their min focusing distance to infinity (DA 12-24, FA 50, DA 50-200, Sigma 170-500 & 17-35) so... it's a little bit unexpected for the new high-end Pentax f2.8 telephoto that is supposed to bring us equivalent technology/performances to 70-200s USM/AF-S offerings from the competition...

I actually compared my DA*50-135/2.8 to my Sigma EX70-200/2.8, which is generally considered a fast AFfing telezoom. Indeed the Sigma travels in slightly over half the time from nearest distance to infinity. However, that time takes it from 1,8m to infinity, whereas the DA*50-135 starts at 1m. The 1,8m mark on the DA*50-135 is half way its travel, so when measuring the time it takes to travel from 1,8m to infinity it is actually faster than the Sigma!!

I think we should be comparing to similar lenses, rather than to primes or standard zooms... If you do that the DA*50-135 isn't that slow at all. Except when it hunts, then it does take more time, but that's solely related to its starting at 1m already...

Just another way of looking at things...

Wim

[Ishpuini]

Thank you for the clarification. This is not my experience at all but as I said I played with it in a shop and that's it, not very meaningfull but I was surprised.

I agree with lol101, I also found the speed of both DA*s to remain more or less the same with or without SDM. I compared the speed before and after the firmware upgrade. Looking through the view finder, SDM does give the impression of being faster, but that's mainly due to the lack of noise and the apparent smoother movement.

Wim

[thibs]

Thanks Wim it does indeed confirm lol101 report.

[mawz]

This test just confirms my observations. I did find K10D AF-C not capable to track moving objects independently from this FNAC testing. However this FNAC test exactly illustrates my findings.

I suspect that the 'double-check' aspect to Pentax's AF system is compromising performance in AF-C mode. The extra confirmation keeps the lens behind what the subject is doing. As I never use AF-C mode, this isn't an issue for me, but it certainly would be for anybody doing sports work.

[mutley]

I suspect that the 'double-check' aspect to Pentax's AF system is compromising performance in AF-C mode. The extra confirmation keeps the lens behind what the subject is doing. it certainly would be for anybody doing sports work.

Yes, this is where a "Sport" mode used in AF-C eliminating this "double check" as explained in my earlier post would be a helpful addition for the next K10D firmware update.

[GaryML]

Seriously, is there any AF system out there which can track kids running around you at close distance (e.g. in the same room)?

Yes. My Nikon system can. Faster AND more accurate for both sports and poorly lighted interiors. Read through my past posts on the subject for full details. I suspect that both Canon and Nikon have many body/lens combination that will focus even faster and more reliably than my Nikon gear, especially the high-end bodies with modern lenses with USM/SWM motors.

Clearly, there is demand for faster and more accurate AF as shown by the fact that Canon, Nikon, Sony and Olympus have just released new products with improved AF systems. Pentax hasn't released a product with upgraded AF since the K10D in the 4th quarter of 2006 (with an AF system that was inferior to the competition at the time).

[mawz]

Yes. My Nikon system can. Faster AND more accurate for both sports and poorly lighted interiors. Read through my past posts on the subject for full details. I suspect that both Canon and Nikon have many body/lens combination that will focus even faster and more reliably than my Nikon gear, especially the high-end bodies with modern lenses with USM/SWM motors.

Clearly, there is demand for faster and more accurate AF as shown by the fact that Canon, Nikon, Sony and Olympus have just released new products with improved AF systems. Pentax hasn't released a product with upgraded AF since the K10D in the 4th quarter of 2006 (with an AF system that was inferior to the competition at the time).

I wouldn't say the AF system in the K10D was anything close to inferior to the competition when released. It was and is far superior to the Sony A100's system, or the AF in any Olympus or Panasonic body other than new E-3 (whose AF is pretty mediocre compared to Oly's claims). It's also better than the XT's AF or most of the Nikon consumer bodies (the D80 is the only Nikon that can reliably AF faster than the K10D in my experience, the D70 and D50 can in good light and in AF-C mode, but fall apart in low light unless you set them to centre sensor only). The Xti and 20D/30D are also faster than the K10D for AF, but are noticeably less accurate unless you have a lens that's f2.8 or faster and are using the centre sensor.

Today of course, you have the A700 with better AF as well, the 40D which is much better than its predecessors and the D300 which will outperform anything else (even the D3, as the D300 has better frame coverage).

[rvannatta]

I wouldn't say the AF system in the K10D was anything close to inferior to the competition when released. It was and is far superior to the Sony A100's system, or the AF in any Olympus or Panasonic body other than new E-3 (whose AF is pretty mediocre compared to Oly's claims). It's also better than the XT's AF or most of the Nikon consumer bodies (the D80 is the only Nikon that can reliably AF faster than the K10D in my experience, the D70 and D50 can in good light and in AF-C mode, but fall apart in low light unless you set them to centre sensor only). The Xti and 20D/30D are also faster than the K10D for AF, but are noticeably less accurate unless you have a lens that's f2.8 or faster and are using the centre sensor.

Today of course, you have the A700 with better AF as well, the 40D which is much better than its predecessors and the D300 which will outperform anything else (even the D3, as the D300 has better frame coverage).

Well, SDM is the solution to faster focusing. Both the K10 and K100 Super are effeectively retrofits on the body end to support the SDM. the Bodies that come floating out in 2008 will be the first bodies that can/should be designed to optimize the use of the SDM capability.

It would not surprise me if they addressed the issue in some respect.

The photos that have nearly always failed for me are the "here comes the bride" shots
where a moving object is coming directly toward you and fairly close range.

[GaryML]

I wouldn't say the AF system in the K10D was anything close to inferior to the competition when released. It was and is far superior to the Sony A100's system, or the AF in any Olympus or Panasonic body other than new E-3 (whose AF is pretty mediocre compared to Oly's claims). It's also better than the XT's AF or most of the Nikon consumer bodies (the D80 is the only Nikon that can reliably AF faster than the K10D in my experience, the D70 and D50 can in good light and in AF-C mode, but fall apart in low light unless you set them to centre sensor only). The Xti and 20D/30D are also faster than the K10D for AF, but are noticeably less accurate unless you have a lens that's f2.8 or faster and are using the centre sensor.

Today of course, you have the A700 with better AF as well, the 40D which is much better than its predecessors and the D300 which will outperform anything else (even the D3, as the D300 has better frame coverage).

The Nikon D80 and D200, and the Canon XTi and 30D, were and are the principal competitors of the K10D, and their AF is definitely faster. I haven't used the Canon XTi and 30D other than testing them for an hour or two, so I can't comment on the AF accuracy.

My D80 does very well with maybe 2% of the shots mis-focused. I am pretty much limited to the center cross-sensor for action use. All of my lenses are f/2.8, except for my 12-24 f/4 (which I don't use for any action or people shots at all-just landscapes). At some point down the road, I will move to a D300 (or its successor) which should give even better performance.

Olympus/Panasonic have always had lousy AF. Minolta was the industry leader in AF with the Maxxum series, but they had fallen on hard times and could not keep up with the competition. Sony rushed out their fisrt SLR as soon as they could, and it had lots of technical problems. But Canon and Nikon combined have something like 80% of the market, so they are the competition.

Well, SDM is the solution to faster focusing. Both the K10 and K100 Super are effeectively retrofits on the body end to support the SDM. the Bodies that come floating out in 2008 will be the first bodies that can/should be designed to optimize the use of the SDM capability.

It would not surprise me if they addressed the issue in some respect.

The photos that have nearly always failed for me are the "here comes the bride" shots
where a moving object is coming directly toward you and fairly close range.

I had the DA* 50-135mm f2.8 SDM lens and it was certainly the best auto-focusing Pentax lens that I used. But I had the same experience that the AF-C simply didn't predict where the moving subject would be when the shutter released. If a kid was running towards me it would consistently focus about 1 foot behind the subject. In the exact same situation, the Nikon nails the proper focus almost every time. Pentax needs more than SDM; it needs a predictive algorithm that works.

[rvannatta]

I had the DA* 50-135mm f2.8 SDM lens and it was certainly the best auto-focusing Pentax lens that I used. But I had the same experience that the AF-C simply didn't predict where the moving subject would be when the shutter released. If a kid was running towards me it would consistently focus about 1 foot behind the subject. In the exact same situation, the Nikon nails the proper focus almost every time. Pentax needs more than SDM; it needs a predictive algorithm that works.

This is the sort of thing that can be added as time goes buy. The screw drive and the double try associated with it was too slow to manage such things. Clearly Pentax didn't go to the trouble of adopting SDM following nearly 20 years behind C---n if they did finally acknowledge that there was an opportunity for a better mouse trap.

It appears that SDM is controled by an interactive data stream between the lens and the camera body which means that for all practical purposes, focus behavior is now a software issue once the hardware is configured to make it as such. The K10 and K100 super which predate the SDM may not fully allow the software to handle the matter, but I cannot imagine that any post SDM body would treat the focusing algorithm as anything but a software control issue. This will allow software guys to write the control algorithm and if it doesn't work, rewrite it for a camera download. I also means that it can be easily made configurable
as to how aggressive you want the predictions to be so you can get those
photos of the charging rhino right up until the camera is knocked over.

The SDM is plenty fast enough mechanically, it just needs a software algorithim that figures out fairly quickly which end of the Rhino it is looking at and tracks accordingly.

It looks like we are going to get a 'live view', and it should be possible to extract from
the 'live view' data set, a dynamic variable which would calculate whether the moving objects were coming or going and how fast. It will still be baffled by a merry-go-around however.

[Ray Pulley]

Yes. My Nikon system can. Faster AND more accurate for both sports and poorly lighted interiors. Read through my past posts on the subject for full details. I suspect that both Canon and Nikon have many body/lens combination that will focus even faster and more reliably than my Nikon gear, especially the high-end bodies with modern lenses with USM/SWM motors.

Clearly, there is demand for faster and more accurate AF as shown by the fact that Canon, Nikon, Sony and Olympus have just released new products with improved AF systems. Pentax hasn't released a product with upgraded AF since the K10D in the 4th quarter of 2006 (with an AF system that was inferior to the competition at the time).

Yeah, like the "improved" top of the line pro Canon MkIII that costs $8k and cannot focus properly...

Ray

[nosnoop]

Pentax hasn't released a product with upgraded AF since the K10D in the 4th quarter of 2006 (with an AF system that was inferior to the competition at the time).

In many independent tests, Pentax system performs as well as other systems. Now, don't take it from me (otherwise, it will be just brushed off as "fanboy" denial), here's Klaus Schroiff's comments in his photozone.de review. Klaus has used all types of cameras including Nikons and Canons, and he has tested majority of the available lenses (hundreds) out there. So he is well positioned to comment on their relative performance. And here are his comments on K10D's AF:

AF Performance
Fast - really fast! AF speed and the accuracy of the K10D are impressive even with the cheap kit lenses and also in dark conditions. The brilliant AF speed also shows up in continuous AF mode.

Pentax K10D Review / Test Report

And I agree with him!
One thing against Pentax is the AF noise. Psychologically, a quiet system would appear faster than a noisy despite very close performance.

[GaryML]

In many independent tests, Pentax system performs as well as other systems. Now, don't take it from me (otherwise, it will be just brushed off as "fanboy" denial), here's Klaus Schroiff's comments in his photozone.de review. Klaus has used all types of cameras including Nikons and Canons, and he has tested majority of the available lenses (hundreds) out there. So he is well positioned to comment on their relative performance. And here are his comments on K10D's AF:

And I agree with him!

Static testing is one thing; field use with moving subjects is another. Both you and Klaus are welcome to come to my son's soccer games and test it for yourself. You are also welcome to come and test it at my son's and daughter's school auditoriums with a mix of artificial lighting that confused the Pentax AF.

My point was to reply to a post that asked if any camera system can focus on kids running close to the photographer. I know from personal experience that the answer is yes. I'm not a fanboy of anything. The real value of forums like this one is to share real-life experiences that go beyond what a magazine tester (or a guy with a Web site, like Klaus) can discover in a one hour or one day test. Using the camera system for seven months and taking thousands of photographs gives you more information on how the camera system works for you than any published review can provide.

[GaryML]

The SDM is plenty fast enough mechanically, it just needs a software algorithim that figures out fairly quickly which end of the Rhino it is looking at and tracks accordingly.

That's true: the fault is not with the lens focus mechanism per se, but with the focus logic in the body. While the in-lens motor is an inherently superior design, even a screw drive AF lens can have quick and accurate AF if the logic in the camera body is up to the task. I've read a number of reports that the Nikon D2 body has excellent AF performance with better quality screw-drive AF lenses, due to a sophisticated AF logic, a powerful AF motor in body, and lots of battery power. I haven't personally used such a system, so I can't say how it would work in my applications. And it is a big, heavy, and expensive ($5,000) camera.

I don't know enough about the specific implimentation of the AF computer in camera bodies to say whether it is just a "software issue." In dedicated, embedded systems where speed is crucial to performance, the hardware is often tailored to the specific software program that is used.