[PDL]

If the so called test was using firmware v1.2 how does RH or anyone else for that matter, really know that the ultrasonic motor was the one being cycled?

Just how was the screw mechanism defined as being disengaged, since these lenses will work on cameras other than the K10D?

The elitist - formerly know as PDL

[Mallee Boy]

Sorry people...outta popcorn and some mongrel spilt all the coke AND the moderators would not allow me to bring in beer.

To be serious for a bit.

Michael (RH) is quite entitled to his views, as is Ben, Peter, Mandi, Chris, Falcons etc etc and even me.
It is a pity that Michael can not accept that what he offers is, at the end of the day, his opinion, nothing more, nothing less.
Whilst that opinion may be researched, and I leave whether researched well or not to the individual, it is still the opinion of one individual.

To have created a website dedicated to reporting flaws is questionable, to provide a link to it on each & every post is more so . Does anyone know if Michael derives any income (directly or indirectly) from his site? I would hazard a guess that, NO, nobody does know.

Can I post a link to my business website? I doubt that would be in the spirit of this fine forum. And lets make no mistake, I believe this is a very fine forum. I recently lurked back at dpr and if anything it has got worse.
For the record I have visited Michaels site(s) / blog but quickly became bored with the content.

I do think that many of the topics Michael raises could be bought forward in a far less confrontational manner, and then he would probably get some conversation around his topics instead of the exasperated attack of the collective groan of "oh cr@p here we go again".

For example, I have long stated that the Sigma 18-125 is not a good performer in low light, but that is my opinion and one that others are free to dis agree with, which has been done, but no one yells at each other and says that this really very good lens is therefore no good....it simply has limitations...inmho.

So finally, to Michael, I have actually heard that you are a quite decent person, very passionate and intense in character with many fine qualities, but please Michael, respect the opinions of others and please be respectful that at the end of the day, you, like me, are offering your opinion. And also for the record, I am still happy with my DS and have had many, many good comments on the photos I produce.

Popcorn?......crownie? (snuck one in)

Cheers people.
Grant

[-spam-]

......crownie? (snuck one in)

Nah, ive got a 6 pack of coronas in an esky sitting next to me

Great post though, pointed out my views on the whole thing exactly so i wont bother repeating. Thank you for being the voice of reason (to me anyway)

[RiceHigh]

I think it has been more than enough discussions which are all around me *personally* which I think all are meaningless and unfruitful.

My OP is simple. I discover a test for the AF motor speed test of the DA* lens and it is clearly shown that the USM is obviously (for both the timing figures and what you can see by our *eyes* in the video) slower than the screw drive body AF motor.

So, that's the information I want to share. I find it to be interesting and of course I do have my opinions. But my opinions are short and simple. Please and do please look back to the OP. My *hope* is that the next Pentax SDM lens should have a stronger SDM motor, *hopefullly* at least not obviously slower than the body AF motor.

Afterall, may I suggest that don't go further on *personal* discussions and let's go back to the topic if you wish to discuss the subject further - but may I ask that please stay close to the topic. In fact, some (but sadly there are just a few of them in these 7 pages of the posts) has raised some relevant good points on topic for further thoughts and sensible discussions (but sadly most of the repliers still mixed up "personal discussions" in their reponses so that I just opted to ignore them all - I do believe replying to all these is just useless and just will lead to more flame wars)

For example, one did reply that the motor turning speed of the focusing scale of the lens is not all about the total AF time and responsiveness. Actually, I have already responed to this point very early in this thread. It maybe yes or maybe no - no one knows exactly until another test is carried out to compare. But, the ability for the motor to focus the lens and the time involved thereafter is the prerequiste for a fast AF and the short AF time - it is just the first thing we need to have for a fast motor for a short AF time - which is *unarguable*. The remaining is the precise detection and control of the AF motor and about the level of perfection of the AF (detection, feedback and control) system including its control logics.

My guess is the SDM *might* have less inertia and that it *might* stop faster than screw driven motor for the lens during focusing but my experience with MZ-S and those SDM lens on K10D is that both control can be achieved to be very good if the AF system is good enough. In the case of SDM on K10D, I just found the motor is just felt to be quite a bit "difficult" to turn and focus the lens fast enough and at least the MZ-S is much faster and start/accelerate much faster and stop also faster and more precisely with less hunting.

Well, people would then say that it is unfair to compare different cameras or even the same camera with different driving methods, but this point is irrelevant as the main point is the DRIVING SPEED of the SDM motors are now found to be slower or simply slow IMO.

As a final question for thought for all you folks and all we Pentaxians: DON'T YOU want the next SDM to be faster (and the AF to be better/improved)??

[Peter Zack]

Here we go... Round 2.

What is the point of discussing "might", "maybe", "possibly", "maybe yes, maybe no". None of this is scientific, none of this is measured, none of this is conclusive. Give me verifiable, independent scientific proof of any of this and maybe I might read it.

But when I shoot 98% of my shots with perfectly fine results (at least in the focus department, the composition etc is an entirely different subject Lol), I really don't give a Rats A** even if it is true. AF accuracy or speed is not perfect on any system.

I'm now 'unsubscribed' to this thread. Cya.

[stewart_photo]

(snip) Off the top of my head I can think of at least 3 people on this forum that are intelligent, articulate, technically savvy, and calm enough to put RH in his place if the rest of us were willing as a community to stay out of the fray. May I suggest that the next time RH posts none of us respond except for Peter Zack, *isteve, and stewart_photo, if these gentlemen would be kind enough to accept the responsibility. (snip)

Well, thanks for the very kind words, but I'll be the first to admit that I'm not all that informed or up-to-date about the many, often wildly esoteric, things RH brings up. I respond to what I can, but often others here are simply better equipped to do so. That's why it's important for the RH threads to be open to those others. And, while I also sincerely appreciate the intelligence, awareness, and patience, of both Peter and Steve (and many others here as well, including yourself), I suspect both of them (and others) may also be thinking along the same lines.

Besides, if I had to respond to RH on a regular basis, I'd probably be pulling my hair out to the point of quickly going bald. And I don't think I'd look all that great absent hair.

stewart

[stewart_photo]

(snip) My OP is simple. I discover a test for the AF motor speed test of the DA* lens and it is clearly shown that the USM is obviously (for both the timing figures and what you can see by our *eyes* in the video) slower than the screw drive body AF motor. (snip)

And, again, a slow or fast motor speed does not directly relate to how fast or slowly a lens finds proper focus. When designing a lens, there is always a balance between how fast a motor turns and how accurately a lens finds the focus point. Just as increased speed in a vehicle cuts down on accuracy (the ability to make sharp turns or stop quickly), increased speed also cuts down the accuracy of a lens. Other factors, such as lens design, focal length, the development progress of a particular AF design, and so on, play a role in all this, with each manufacturer making choices based on those many factors.

Pentax clearly felt the existing motor speed balanced well with those other factors. And only more extensive testing, beyond just a simple measurement of the motor speed, will show how well that choice compares to the choices made by other manufacturers. In the end, I suspect the manufacturers' design variations (which include variations in motor speeds) will result in only very small differences in actual focusing speed between lenses ('actual focusing speed' defined as the time it normally takes a lens to fully achieve proper focus).

stewart

[Falcons]

My guess is the SDM *might* have less inertia and that it *might* stop faster than screw driven motor for the lens during focusing but my experience with MZ-S and those SDM lens on K10D is that both control can be achieved to be very good if the AF system is good enough. In the case of SDM on K10D, I just found the motor is just felt to be quite a bit "difficult" to turn and focus the lens fast enough and at least the MZ-S is much faster and start/accelerate much faster and stop also faster and more precisely with less hunting.

As a final question for thought for all you folks and all we Pentaxians: DON'T YOU want the next SDM to be faster (and the AF to be better/improved)??

Ricehigh on the first point - How would you know anything about the K10D as you don't even own one?

Second point - Of course everyone wants faster everything the question though is pricing of the camera with faster AF faster fps etc. Pentax is not yet in the high end market and it would be akin to suicide for them to bring out a high end camera for the minority of Pentax owners who could afford such a beast, without the foundation of a strong selling entry level camera. Now you may say a faster AF on the entry level camera will lead to more sales, but that would require a heap of marketing to push that. Pentax is growing because they produce affordable cameras; simple as that.

Now my third point (and this is the third time I have asked it.) You are a supposedly proud measurebater - now please conduct one of your tests with the your K100D up against the canon 5D and tell me exactly how much faster the canon is at AF. It is a simple question that you continually ignore, but I would love to know are we talking seconds, minutes, milliseconds or nanoseconds. Cause I can tell you right now my DS is more than adequate for me and I don't have any problems.
Anyway the challenge is there - are you up to it?

[Maxington]

My OP is simple. I discover a test for the AF motor speed test of the DA* lens and it is clearly shown that the USM is obviously (for both the timing figures and what you can see by our *eyes* in the video) slower than the screw drive body AF motor.

For example, one did reply that the motor turning speed of the focusing scale of the lens is not all about the total AF time and responsiveness.

I posted this on your blog in the comments section.

I compared a DA* 16-50 to my housemates 20D, with a 135 f2.0 USM, and the Canon lens is TWICE as slow to travel its full range. The DA* is at rest for probably a second before the Canon lens finishes its travel.

Same test, with a Tamron 28-75 f 2.8 on the 20D, the DA* finishes earlier. Compared the Tamron with the Canon 135, the Tamron also finishes far sooner than the Canon lens.

What does this mean? Absolutely nothing. The Canon 135 focuses the fastest by a long shot against the Tamron on the same body, and kicks the pants off the DA* on the K10D. Its an expensive and brilliant lens, and focus on it is blindingly fast. But it has by far the slowest full travel of the three lenses. If I had any video camera I could record it as well as a rebuttal.

The travel time of a lens as shown in this test means nothing. We simply do not know what the electronic system is doing at the time, for example the SDM/USM motor could be (and most likely is) far more controllable than a screw drive mechanism, which could be faster simply because it has a simpler, on/off, max speed/no speed switch.

To recap, the slowest (by far) lens of the 3 I tested, is the fastest (by far) at actual AF. Everyone with a few different lenses, or even different cameras, go do the simple test, you'll see that the travel time is just meaningless, the same as this test is.

[RiceHigh]

Your test is interesting, but there are just too many variables that we can actually draw no conclusion of any as you supposed to prove. I did think and say that the travelling speed is not all about the total AF system time, but your proof of the travelling speed is irrelevant to the total AF time is invalid, as you just compare different lens and body combos. Just e.g., if the K10D hunts more at the final stage to confirm focus, then it will surely have the results you've obtained, i.e., an longer overall AF system time.

I posted this on your blog in the comments section.

I compared a DA* 16-50 to my housemates 20D, with a 135 f2.0 USM, and the Canon lens is TWICE as slow to travel its full range. The DA* is at rest for probably a second before the Canon lens finishes its travel.

Same test, with a Tamron 28-75 f 2.8 on the 20D, the DA* finishes earlier. Compared the Tamron with the Canon 135, the Tamron also finishes far sooner than the Canon lens.

What does this mean? Absolutely nothing. The Canon 135 focuses the fastest by a long shot against the Tamron on the same body, and kicks the pants off the DA* on the K10D. Its an expensive and brilliant lens, and focus on it is blindingly fast. But it has by far the slowest full travel of the three lenses. If I had any video camera I could record it as well as a rebuttal.

The travel time of a lens as shown in this test means nothing. We simply do not know what the electronic system is doing at the time, for example the SDM/USM motor could be (and most likely is) far more controllable than a screw drive mechanism, which could be faster simply because it has a simpler, on/off, max speed/no speed switch.

To recap, the slowest (by far) lens of the 3 I tested, is the fastest (by far) at actual AF. Everyone with a few different lenses, or even different cameras, go do the simple test, you'll see that the travel time is just meaningless, the same as this test is.

[carpents]

This is a question for moderators and for other members also. Would it be possible (or advisable) to establish a given number of complaints (say ie. complaints coming from 50 members or more) so if somebody exceed them he/she would be banned.

Good suggestion, however I wonder if it will work.
One could easily register under an other nickname / email combination. It wouldn't stop persistent posters.

Please! Ban them for what? For posting a blog link about someone else's test? I vote that we ban people who suggest that others be banned.

If you don't like one person's opinion, no matter how obstinate or incorrect, you have an option to rebut them or ignore them.

Well, people would then say that it is unfair to compare different cameras or even the same camera with different driving methods, but this point is irrelevant as the main point is the DRIVING SPEED of the SDM motors are now found to be slower or simply slow IMO.

As a final question for thought for all you folks and all we Pentaxians: DON'T YOU want the next SDM to be faster (and the AF to be better/improved)??

No, I don't want faster SDM - if - it costs significantly more or is less accurate or is much bigger/heavier. We must assume that Pentax did this analysis and came up with the designs that they did. It really is a matter of business as well - let's not ignore those other variables and make it any simpler than it already is.

[Maxington]

Your test is interesting, but there are just too many variables that we can actually draw no conclusion of any as you supposed to prove. I did think and say that the travelling speed is not all about the total AF system time, but your proof of the travelling speed is irrelevant to the total AF time is invalid, as you just compare different lens and body combos. Just e.g., if the K10D hunts more at the final stage to confirm focus, then it will surely have the results you've obtained, i.e., an longer overall AF system time.

If one test is invalid then both are. If a test says "this motor takes longer to travel than this one, thus AF will be worse" and you test travel speed on other lenses and cameras, its completely valid to point out that travel speed is not ANY sort of indicator of AF speed. How fast a lens can whip back and forward across its range does NOT correlate to its AF ability, this is testable and noticable by anyone.

Its similar to testing cars, if one engine can rev at 9000rpm and another at 5000rpm, that doesn't mean a damn thing to the cars actual speed, regardless of the car type. But you can test multiple cars under the same conditons and see that a certain car is faster. You don't discount a speed test because they aren't all the same brand of car, or the same engine.

Exactly the same with lenses, a lens is fast at AF, but slow at travel, another lens is slow at AF, but fast at travel, another is fast at travel and fast at AF, the obvious conclusion is the travel simply doesn't MATTER. Remember, this is NOT a test of motor speed, its a test of the speed of travel. You do not know that all lens motors operate flat out under those conditions, or even if operating flat out is an advantage to AF or not.

You are taking the results of a test and running with it to a pre-conceived conclusion, skipping a dozen factors on the way.

[jeffkrol]

If one test is invalid then both are. If a test says "this motor takes longer to travel than this one, thus AF will be worse" and you test travel speed on other lenses and cameras, its completely valid to point out that travel speed is not ANY sort of indicator of AF speed. How fast a lens can whip back and forward across its range does NOT correlate to its AF ability, this is testable and noticable by anyone.

Its similar to testing cars, if one engine can rev at 9000rpm and another at 5000rpm, that doesn't mean a damn thing to the cars actual speed, regardless of the car type. But you can test multiple cars under the same conditons and see that a certain car is faster. You don't discount a speed test because they aren't all the same brand of car, or the same engine.

Exactly the same with lenses, a lens is fast at AF, but slow at travel, another lens is slow at AF, but fast at travel, another is fast at travel and fast at AF, the obvious conclusion is the travel simply doesn't MATTER. Remember, this is NOT a test of motor speed, its a test of the speed of travel. You do not know that all lens motors operate flat out under those conditions, or even if operating flat out is an advantage to AF or not.

You are taking the results of a test and running with it to a pre-conceived conclusion, skipping a dozen factors on the way.

Be prepared to hit the illogic wall,
Now I'm getting my popcorn

Please! Ban them for what? For posting a blog link about someone else's test? I vote that we ban people who suggest that others be banned.

Please, you took some time to read that post and reply it even if it was posted yesterday. If you expend that time in that you can also expend it reading my previous and the following posts. You will discover that I dont think that RH should be banned. Moreover, personally I am against any sort of banning except those involving criminal activities against me. I was just trying to suggest a way to make the life easier for those who cannot stand RH comments instead of taking the route of personal disqualifications. If you read carefully my post you will see that I never said that I would vote for that banning. Now I agree with you, vote me for banning or for president that is up to you but as much as I value most of your posts (specially those regarding technical issues) this one in particular makes me thing that you might well be in a trolling mood.

You see how easy is to troll a little. Please ban me! I am trolling now!!!

[carpents]

Please, you took some time to read that post and reply it even if it was posted yesterday. If you expend that time in that you can also expend it reading my previous and the following posts. You will discover that I dont think that RH should be banned. Moreover, personally I am against any sort of banning except those involving criminal activities against me. I was just trying to suggest a way to make the life easier for those who cannot stand RH comments instead of taking the route of personal disqualifications. If you read carefully my post you will see that I never said that I would vote for that banning. Now I agree with you, vote me for banning or for president that is up to you but as much as I value most of your posts (specially those regarding technical issues) this one in particular makes me thing that you might well be in a trolling mood.

You see how easy is to troll a little. Please ban me! I am trolling now!!!

Hmmm...I read your other posts, but did not put them together as yours - because they seem to be at odds with one another. You sandwich the post about 'possibly banning' someone by saying that you do not favor banning, so you'll have to forgive me for misinterpreting the post, not for selectively reading it!

One of the main reasons I abandoned dpreview was the Draconian rules regarding banning (or not) of participants. So I'll admit to being easily trolled into responding when it comes to this!

Okay, back on topic...