Slow AF?


johnriley

Link Posted 17/02/2010 - 17:27
Let's move back to the discussion please, otherwise we'll get stuck on who gets the last word in.

It should be possible to discuss this without the personal stuff. Otherwise we end up with taboo subjects, which is quite unnecessary.
Best regards, John

aminstar

Link Posted 17/02/2010 - 17:51
I am not the one bringing personal stuff into the discussion John. Anyone who accompanies the thread and reads all my comments will notice the merits of Pentax that I keep mentioning. And also the pitfalls of other brands as some of the fast AF systems are not just plain sailing.

I know a few that have jumped ship and then ended up not fully happy because of high expectations, thinking that it was all plain sailing and they could just get the short comings of Pentax, in this case slower AF, all sorted out like a magic wand, but that's not the case. They all have their complexities. Unlike many who might have just jumped ship and talk down Pentax and their users I am not like one of them because I have a clear head of the merits and beauty of Pentax and hold the members here in very high esteem. It was here that I took my baby steps in photography after all and that is also one reason that I am here.
Amin Photo Gallery

johnriley

Link Posted 17/02/2010 - 17:54
I'm not singling out anyone, let's just move on.
Best regards, John

iceblinker

Link Posted 17/02/2010 - 17:57
Amin, I apologise for my personal comments. They were out of character for me. We've had friendly discussions before, and I hope we will again.
~Pete

TOZZA27

Link Posted 17/02/2010 - 17:58
Mike p

If you want to invite Jo & I down to the New Forest for a couple of days I`m sure your AF would lock on to we two - lol
K20D,*istD ( now a dedicated M42 digital ),K100D,MZ5N,P50,ME Super,Spotmatic 1000,Spotmatic,ESII,ES,H2.18-55 II,18-55,75-300 FAJ,35-80 FA,80-200 F,28-105 FA,Sigma 24-70 AF Aspherical,Sigma 28-300 Hyperzoom , Praotor II 500 M42,Centon 500mm mirror,and a few Pentax M42 Taks,super-Taks,smc Taks,A and M lenses.Benbo trekker,7dayshop monopod and a Lowepro rucksack.

I am now on Flickr which is nice !

aminstar

Link Posted 17/02/2010 - 18:14
iceblinker wrote:
Amin, I apologise for my personal comments. They were out of character for me. We've had friendly discussions before, and I hope we will again.

No problem, am just glad that my point is not misinterpreted. We can certainly have a constructive debate on anything. For a moment I was starting to think that I was unwelcome here. Just a couple of days ago I helped a very good friend of mine buy a Pentax kit and I still think it was the best choice. I personally am lazy and probably not very talented hence looking for easier ways out and that is more with regard to AF particularly.
Amin Photo Gallery

K10D

Link Posted 17/02/2010 - 19:32
Anvh wrote:
K10D wrote:
Quote:
ChrisA wrote:
Gwyn wrote:
It would be nice if Pentax could improve their AF speed if only to stop discussions like this recurring constantly.

Careful - that point is (almost) unarguable, and that would never do

Well we could then start an argument then that the slower AF was more accurate

Aye, the slower the better.

link

Regards


I would just say users error, you just need to know when the press the button
But honestly though you can't prove the photo is out of focus because of slow AF neither can I that it was user error.

Then again Daniel did manage to capture these... link



I do agree but if the setting is AF release, you stand a chance. Either way, my latest input of macro/close up shots are all MF so AF speed and its related issues are irrelevant. The only whine going on is the lack of a comparable AF speed to other systems. I also wish that Pentax had a fast AF system, the fact is they presently don't, so if you do need that function, buy a system that does have it. I did not buy into Nikon for fast AF, I did so for FF and the low noise high ISO qualities.

I only have my K7 with me plus lenses because its easy to travel with and produces the results (if I get my settings right). It's horses for courses and no amount of discussion will sort that out. The Pentax system is a truly wonderful system but it does not perform in certain areas. If it did, it would be the only system in use or for that matter any other make that did it all.

Regards
Last Edited by K10D on 17/02/2010 - 19:34

Anvh

Link Posted 17/02/2010 - 21:20
K10D I'm glad you didn't took my comment as an offence, was just applying that the matter is not as simple as just a faster AF there is much more to it

You can't really lay your finger on the matter why the SDM is quite slow where for example the Sigma version is faster.
For me the AF speed is also not a problem with macro or portrait work fast AF is not needed at all, only for wildlife and most forms off sport a fast AF is better and for the kids playing in the yard for the rest a bit slower AF is not a problem.

To be honest I think we are making more problem about it then it really is.

If they want a good AF system they should copy the one of the D300 with that tracking system, let's hope things will be improved with the upcoming camera's the build quality of the K7 is at least good so a newer sensor (not the K-X type please) and newer AF is just all it needs.
Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ

Lance B

Link Posted 18/02/2010 - 00:30
RichardDay wrote:
Anvh wrote:
Quote:
Anvh wrote:
the DA40 is a real speed demon, it can focus to close up to infinite and back in less then a second and it looks it's so because of the small focus throw.

Now this really nails the argument. If Pentax can make DA40 so fast at focusing why on earth wouldn't they make their newer and expensive SDM lenses fast also? This I fail to comprehend. In fact the sluggishness of the DA*60-250 was so annoying that I used to pull my hair everytime I tried to focus and now I have ended up with little hair. And if I had kept at it I would have lost the rest of it too.

I think it's because the DA* lenses have a longer focus throw to make it more accurate, that's why I was interesting in how it was with the canon lenses.

btw all the DA limited lenses seem to focus very fast, don't know about the FA though.
Here is a little review about the DA40 and the DA70 where you cans ee the focus speed. link
Around the 3:00 mark for the DA40 and around the 6:00 for the DA70 they go from close to infinite I believe or vice versa
Glad to make a Canon user jealous

ps another film K7 vs 7D link
The K7 isn't doing it that bad right, I wonder if they could throw more power over the contacts to make the SDM move faster.

SDM lenses don't all have a long focus throw. The DA 17-70 is very small and the DA*60-250 is not that much more either, the DA*55 is very long and is very slow end to end.

In decent light the 17-70 is about as fast as the DA 16-45, the 60-250 is maybe a bit slower. I compared my DA*60-250 againt the Sigma 150-500 HSM on a fairly dull day in December and I didn't notice much difference in the AF speed, both were fairly quick and positive.

Tha fastest focussing lens I ever had was the FA*24, it was faster than the DA 40 which is very quick. I've had, or tried, most of the FA and DA lenses (including *'s and Limiteds) at one time or another and would say that SDM has no speed advantage over screwdrive AF lenses or vica versa. AF speed seems very dependent on the rotational length and the mass of the focussing element, and, of course, the light levels and contrast.

I've used a Canon 1D mkII, the 70-200 f4 L and 100-400 L lenses and it was blisteringly quick with both, you almost didn't notice it focussing. I wish you could get the same performance in a package in less than half the size and weight! Some say the Oly E3 and their latest SWM lenses is a fast combo.

I find my K20D more than adequate with the 60-250 and I would say I get around 70% in focus shots when I'm birding and that's pretty high. The number of keepers is much less due to my inadequate skills!



I concur with Richard's assessment of the Pentax system, although I have not formerly tried the Canon 1D. Much of the "slow" AF has to do with long focus throw of some of the Pentax lenses and the desire for accuracy over speed. Having said that, I am sure it could be sped up to some degree.

As a few other's have pointed out, having good technique and knowing how your equipment operates/functions/reacts in certain situations is a good way to "getting the shot". Pro's are pro's as much because they are well versed in their trade and part of this is knowing how their equipment works under all conditions. This is partly why they "get the shot" more often than not and not always simply because they "have the best equipment".
Cameras:K-7/K20D/*ist D/K10D
Lenses:DA14 f2.8, A16 f2.8, FA20 f2.8, FA31 f1.8, DA35 f2.8 macro, FA43 f1.9, FA50 f1.4, A50 f1.4, A50 f1.2, FA50 f2.8 macro, DA*55 f1.4, FA77 f1.8, DFA100 f2.8 macro, A100 f2.8, DA*300 f4, FA*300 f4.5, DA10-17 FE, DA12-24 f4, DA*16-50 f2.8, DA17-70 f4, FA*28-70 f2.8, DA*50-135 f2.8, DA*60-250 f4, FA*80-200 f2.8.
Flashes:AF540FGZ, AF360FGZ

i-Berg

Link Posted 20/02/2010 - 04:30
Well said, Lance.

To expand on this -

the pros are aware of the shortcomings / weaknesses of their gear, whatever brand it is; and

they know how to work around, avoid, or compensate for, those areas.

So the forum direction could perhaps now be less about problem identification, and more about techniques and solutions to overcome whatever the issues might be.

Any suggestions from the practitioners?
http://www.pbase.com/iberg

RichardDay

Link Posted 20/02/2010 - 16:50
i-Berg wrote:
Well said, Lance.

To expand on this -

the pros are aware of the shortcomings / weaknesses of their gear, whatever brand it is; and

they know how to work around, avoid, or compensate for, those areas.

So the forum direction could perhaps now be less about problem identification, and more about techniques and solutions to overcome whatever the issues might be.

Any suggestions from the practitioners?

Yes!

Read books by those who are proficient in the particular field of photography (go to the public libraries, the best source of books!) and then ...

Practice ... Practice ... Practice ... and .. Yet more practice!
Best regards
Richard Day

Profile - link - (click on About for equipment profile) - My Flickr site - link

Mike-P

Link Posted 20/02/2010 - 20:15
RichardDay wrote:

Yes!

Read books by those who are proficient in the particular field of photography (go to the public libraries, the best source of books!) and then ...

Practice ... Practice ... Practice ... and .. Yet more practice!

Alternatively just buy a Nikon or Canon .... (runs and hides).
No equipment list here but thanks for taking an interest. My Flickr

Anvh

Link Posted 20/02/2010 - 21:54
Mike-P wrote:
RichardDay wrote:

Yes!

Read books by those who are proficient in the particular field of photography (go to the public libraries, the best source of books!) and then ...

Practice ... Practice ... Practice ... and .. Yet more practice!

Alternatively just buy a Nikon or Canon .... (runs and hides).

Yeah but those also have their problems... perfect solution would be to buy the best camera and lens for every specific situation and type of photo... you probably will end up with 18 bodies and 96 lens if not more, but hey, you would always have the best gear for the job... if you didn't leave it at home
Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Last Edited by Anvh on 20/02/2010 - 21:55

Mike-P

Link Posted 20/02/2010 - 22:05
Anvh wrote:
Yeah but those also have their problems... perfect solution would be ..........

Did you not notice the Stefan.
No equipment list here but thanks for taking an interest. My Flickr

Anvh

Link Posted 20/02/2010 - 22:08
Mike-P wrote:
Anvh wrote:
Yeah but those also have their problems... perfect solution would be ..........

Did you not notice the Stefan.

Indeed just thought I should explain your thoughts behind the comments a bit more

or am I off the point you're trying to make?
Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
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