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AF on the X Pro 1

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I hear you, but the Contax G2 wan't a rangefinder in todays sense of the word. As you of course know, there is no actual mechanical rangefinder on the camera.

As for the size, take a look here: http://camerasize.com/compare/#258,187

Especially the sideway look might surprise you. And it might interest you to know that the Fuji 35mm F/1.4 for instance actually is over 20% shorter than the Pentax 31mm F/1.8, even though it's faster, and sits on a much shallower body. The 18mm is another very, very compact Fuji lens compared to anything similar from Pentax.
Robgo2 said:
In my film days, I used a Contax G2, which was a true rangefinder with autofocus and autometering. I had no interest in all-manual shooting, and I still don't. It makes no difference to me whether a camera uses a genuine rangefinder focusing mechanism or something else, as long as it does the job quickly and accurately. However, I appreciate the fact the some photographers enjoy the manual shooting process. Good luck to them finding affordable digital rangefinder cameras that can serve that purpose.

The X-Pro 1 looks like what a digital Contax G might have been and, therefore, is of interest to me. However, I am a Pentax shooter, and the Pentax K-5/K-7 bodies and Limited lenses are not much larger than the new Fuji, which means that the IQ from the X-Pro 1 is going to have to be stupendous to get me to even considering switching. I realize that we Pentaxians are a rarity around here, but we really appreciate the fact that Pentax has placed a priority on small size and high quality. Other manufacturers are only now catching on.

Rob
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Lol this is ludicruous: AF speed has nothing to do with the sensor's size.

It has instead very much to do with the size of the lenses to be shfited by the interna focussing mechanism and the kind of motors, as demonstrated in m4/3.

Is Fuji aware of this? Because if the early lenses are not well designed they will have to be revamped or thrown away to achieve a faster focus as demonstrated in m4/3.

Now you can do it with a 100 $ kit lens but surely not with an expensive prime.

Before putting lenses on the market Fuji would do well to check how compatible heavy primes are with fast CDAF, because they are not. The other part of fast CDAF is processing power. But even if you have great processing power, a heavy lens won't budge fast enoughto carry the instructions.

Am.
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Photostream: http://www.flickr.com/photos/amalric
 
Sensor size has a something to do with it, because image circle affects lens element size, which affects the mass the AF motor needs to move. But more importantly, DOF affects AF speed very much, because the thinner the DOF is, the more precise the movements of the AF motor needs to be. The 20mm F/1.7 and 25mm F/1.4 m43 lenses aren't AF speed-demons.
amalric said:
Lol this is ludicruous: AF speed has nothing to do with the sensor's size.

It has instead very much to do with the size of the lenses to be shfited by the interna focussing mechanism and the kind of motors, as demonstrated in m4/3.

Is Fuji aware of this? Because if the early lenses are not well designed they will have to be revamped or thrown away to achieve a faster focus as demonstrated in m4/3.

Now you can do it with a 100 $ kit lens but surely not with an expensive prime.

Before putting lenses on the market Fuji would do well to check how compatible heavy primes are with fast CDAF, because they are not. The other part of fast CDAF is processing power. But even if you have great processing power, a heavy lens won't budge fast enoughto carry the instructions.

Am.
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Photostream: http://www.flickr.com/photos/amalric
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I don't know about the autofocus but, at $2400 US, it's too rich for my blood. I can't see the price of twice that of an X100 makes it that much better then the X100. The X100 is much smaller and look much nicer.

Looks like I'm going to have to wait for an X200 or an X Pro-2 and see if they clean up their niggles.
 
Jon Rty said:
Sensor size has a something to do with it, because image circle affects lens element size, which affects the mass the AF motor needs to move. But more importantly, DOF affects AF speed very much, because the thinner the DOF is, the more precise the movements of the AF motor needs to be. The 20mm F/1.7 and 25mm F/1.4 m43 lenses aren't AF speed-demons.
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Not caring to discuss equivalence. AF was lagging in the early Pens until they made them internal focussing. And yet it is the only difference in the kit lens. I know, I had both versions.

My argument is not that Fuji is not going to get there, but that it needs further experience and development. O&P wisely started with consumer cameras and learned by doing. Fuji started from the top and might have made a costly error that it will fix later.

My worry is about the lenses, though, not the body. Because if they are not designed for quick AF they might need to be chucked later, exactly like I had to do with my kit lens. But Fuji's lenses are worth 3 times the price.

I am interested by the camera because of its original design and high IQ, but the AF matter puts me on standby. It took 2 full years to Oly to fix the AF problem.

Am.
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Photostream: http://www.flickr.com/photos/amalric
 
amalric said:
Jon Rty said:
Sensor size has a something to do with it, because image circle affects lens element size, which affects the mass the AF motor needs to move. But more importantly, DOF affects AF speed very much, because the thinner the DOF is, the more precise the movements of the AF motor needs to be. The 20mm F/1.7 and 25mm F/1.4 m43 lenses aren't AF speed-demons.
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Not caring to discuss equivalence. AF was lagging in the early Pens until they made them internal focussing. And yet it is the only difference in the kit lens. I know, I had both versions.

My argument is not that Fuji is not going to get there, but that it needs further experience and development. O&P wisely started with consumer cameras and learned by doing. Fuji started from the top and might have made a costly error that it will fix later.

My worry is about the lenses, though, not the body. Because if they are not designed for quick AF they might need to be chucked later, exactly like I had to do with my kit lens. But Fuji's lenses are worth 3 times the price.

I am interested by the camera because of its original design and high IQ, but the AF matter puts me on standby. It took 2 full years to Oly to fix the AF problem.

Am.
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The motor has a lot to do with it, you're right, but CDAF algorithm plays a significant part too. For example, Olympus has had 3 kit lenses. They had a mark I, a mark II, and a mark IIR if I remember correctly. The mark II and mark IIR are actually the same exact lens on the inside. The only difference is that the IIR has undergone a nice cosmetic change on the outside.

I remember reading the Olympus forums and people complaining that in order to get that fast autofocus speed on their EP3, they now had to buy yet another kit lens. People were not happy. Then Olympus released a firmware update for the mark II and then it focused as fast as the IIR on the EP3. On the EP2/1 it's not any better because the CDAF isn't as good.

I saw a video review of the EP3 by Kai from DigitalRevTv and he talked about how the autofocus speed on the 17mm pancake was dog slow on the EP2/1, but that on the EP3 it was "alright". In that case, the motor speed is the limiting agent because it doesn't have the newer MSC motors.

You're correct in bringing attention to the motors of these lenses though. I remember when I first received my X100 I was surprised at how noisy the focus motor was. It sounded like R2D2, having been used to silent motors like those found in the NEX cameras. I've always wondered if a noisy motor like in the X100 has less torque and speed than a silent motor like that found in a NEX lens.

It's possible Fujifilm simply does not have access to better motors for their lenses, so they are stuck with what they can patent and buy from other suppliers. I don't know if its true, but I heard that Sony bought motors from Canon because they didn't have something to match the USM. Someone posted a video taken from the X-Pro1 on youtube, taken with the 60mm lens and the focusing motor was noisy. So I imagine its the same as that found on the X100.

So back to the original question, will the motors in these lenses be a limiting factor for autofocusing speed? I think its hard to say at this point. A large part of the problem with the autofocusing of the X100 isn't so much the speed as it is the reliability.

Too often the camera hunts or cannot find enough contrast to autofocus in situations where other CDAF cameras would do just fine. From the few videos and reports let out so far, the X-Pro1 seems to suffer from the same temperamental CDAF algorithms.

Then there is the refresh rate pulled off the sensor that is also a factor.
 
There is not much difference between the Oly 14-42 2nd and 3d version, but between those and the 1st version which was not internal focussing, but had a rotating front element.

There is a lot of confusion in the m4/3 camp, I am speaking only out of experience. the 17mm for instance is not internal foscussing but behaves well through different camera generations because it has short focussing excursion.

Also doubliing the sampling rate, as in the 3d generation Olys, helps both conformal lenses and the EVF refresh rate, and the recording rate of the card.

So when going mirrorless a maker has to watch out for a lot of parameters and keep them in harmony, like an orchestra director. It's not a matter of finding one culprit, but of harmonising a camera, and that might take time.

'less than 1 sec' as a reviewer put the AF, shows that these problems must still be addressed by Fuji. I dearly hope they do.

Am.
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Photostream: http://www.flickr.com/photos/amalric
 
Yet, it seems to be on par with equivalent m43 lenses.
amalric said:
There is not much difference between the Oly 14-42 2nd and 3d version, but between those and the 1st version which was not internal focussing, but had a rotating front element.

There is a lot of confusion in the m4/3 camp, I am speaking only out of experience. the 17mm for instance is not internal foscussing but behaves well through different camera generations because it has short focussing excursion.

Also doubliing the sampling rate, as in the 3d generation Olys, helps both conformal lenses and the EVF refresh rate, and the recording rate of the card.

So when going mirrorless a maker has to watch out for a lot of parameters and keep them in harmony, like an orchestra director. It's not a matter of finding one culprit, but of harmonising a camera, and that might take time.

'less than 1 sec' as a reviewer put the AF, shows that these problems must still be addressed by Fuji. I dearly hope they do.

Am.
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Photostream: http://www.flickr.com/photos/amalric
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Hard to know what to make of it without seeing it tested in real life. I have a Leica X1 which I love dearly; every review comments on its slow autofocus but it does everything I want it to without being frustrating. But I like landscapes and cityscapes - trees and buildings don't tend to move about much. I don't want to be Cartier-Bresson.

BUT: some people DO want to be HCB. Why would Fuji cut off this portion of the market with poor manual focus? This does not make sense. I was hoping Fuji would out-Leica Leica, but it seems the Fatherland is still safe.

Let's see what the first clinical trials produce, all we have now is rep-speak.
 
I would rather have a slow accurate AF than a fast one that has a problem with focusing A pro could use this in a studio or for landscape back in the film day's 28MM was the norm for that.people today are just to spoiled. --

My gear: 5DmkII,7D,300mm2.8Lis,70-2002.8Lis,17-40f4L,851.8,501.4,1002.8 macro,2 580ex flashes,twin macro flash,oly E-P1
 
The 20mm is a 1gen lens, therefore slow. The 25/1.4 has not fast AF?

Please quote figures, if you have them, instead of guesses.

BTW I am talking about lenses I effectively have, like the 14-42. So I know what is real AF speed, It's instant, not 'less than 1 sec' (Gizmodo) LOL.

Am.
Jon Rty said:
The XP1 was tested with the 35mm F/1.4, if I'm not mistaken. The similar m43 lenses would be the 20mm F/1.7 and 25mm F/1.4.
amalric said:
What is on par, pray?

'Less than one second' lenses?

LOL 3gen Pens are 0.1-0.2 sec capable.

Laziness has limits :)

Am.

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Photostream: http://www.flickr.com/photos/amalric
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Photostream: http://www.flickr.com/photos/amalric
 
The Pana-Leica 25mm F/1.4 is a AF lens. What would quoting numbers tell you, when the test isn't performed in the same way? What I can tell you is that the Pana-Leica isn't up to the focusing speeds of the Olympus 14-42mm and 12mm. Which is to be expected, because there's a huge difference in DOF.
amalric said:
The 20mm is a 1gen lens, therefore slow. The 25/1.4 has not fast AF?

Please quote figures, if you have them, instead of guesses.

BTW I am talking about lenses I effectively have, like the 14-42. So I know what is real AF speed, It's instant, not 'less than 1 sec' (Gizmodo) LOL.

Am.
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Jon Rty said:
The Pana-Leica 25mm F/1.4 is a AF lens. What would quoting numbers tell you, when the test isn't performed in the same way? What I can tell you is that the Pana-Leica isn't up to the focusing speeds of the Olympus 14-42mm and 12mm. Which is to be expected, because there's a huge difference in DOF.
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Interesting theory. So you assume that AF speed depends on DOF? And not on how quickly the focussing lens is shfited inside the barrel, which is the common knowledge?

I see no AF speed difference between teles and wides of the same generation.

I am always amazed at the lengths fanboys will go to defend their own wares, against any evidence of their lacking.

BTW I am sincerely impressed by the performance of the new sensor and that is why I keep coming here. As I said above AF problems sooner or later will be solved. I am interested by a system in the making, not in one camera fetish.

If quite a few journalists complain about the lagging AF I shift my attention to what can be done with pre-focus anyway. I am not in denial of what people noticed in the flesh.

Or perhaps you are burning heretics at the stake here? LOL

Am.
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Photostream: http://www.flickr.com/photos/amalric
 
I'm a right in assuming that your experience is limited to m43? That DOF affects AF speed is common knowledge as well, the thinner the DOF, the more precises does the focus motor need to be. Look at Canon and Nikon, their fast primes focus much, much slower than their F/2.8 zooms.

Oh, and trying to paint those who disagrees with you as fanboys does you no favors. I have no dog in this race, I'm merely trying to share some knowledge.
amalric said:
Interesting theory. So you assume that AF speed depends on DOF? And not on how quickly the focussing lens is shfited inside the barrel, which is the common knowledge?

I see no AF speed difference between teles and wides of the same generation.

I am always amazed at the lengths fanboys will go to defend their own wares, against any evidence of their lacking.

BTW I am sincerely impressed by the performance of the new sensor and that is why I keep coming here. As I said above AF problems sooner or later will be solved. I am interested by a system in the making, not in one camera fetish.

If quite a few journalists complain about the lagging AF I shift my attention to what can be done with pre-focus anyway. I am not in denial of what people noticed in the flesh.

Or perhaps you are burning heretics at the stake here? LOL

Am.
--
Photostream: http://www.flickr.com/photos/amalric
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Well I've seen posts over at the nex forum that autofocusing slows down on the tele end of lenses like the 18-200. Focusing at macro distances is also more difficult.

kaycee baker from fuji said that the 35mm has an f1.4 aperature and that, "that helps" with regards to autofocusing. As far as I know, cdaf cameras open the aperature to the max setting to let in more light. So I'm not sure how dof is going to factor in there.

another thing I've noticed is that if you try to focus on an oof background, the x100 has trouble finding focus. I thibk that because it's out of focus the algorithym has trouble finding the highest point of contrast.
Jon Rty said:
I'm a right in assuming that your experience is limited to m43? That DOF affects AF speed is common knowledge as well, the thinner the DOF, the more precises does the focus motor need to be. Look at Canon and Nikon, their fast primes focus much, much slower than their F/2.8 zooms.

Oh, and trying to paint those who disagrees with you as fanboys does you no favors. I have no dog in this race, I'm merely trying to share some knowledge.
amalric said:
Interesting theory. So you assume that AF speed depends on DOF? And not on how quickly the focussing lens is shfited inside the barrel, which is the common knowledge?

I see no AF speed difference between teles and wides of the same generation.

I am always amazed at the lengths fanboys will go to defend their own wares, against any evidence of their lacking.

BTW I am sincerely impressed by the performance of the new sensor and that is why I keep coming here. As I said above AF problems sooner or later will be solved. I am interested by a system in the making, not in one camera fetish.

If quite a few journalists complain about the lagging AF I shift my attention to what can be done with pre-focus anyway. I am not in denial of what people noticed in the flesh.

Or perhaps you are burning heretics at the stake here? LOL

Am.
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Photostream:
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Photohobbyfun said:
kaycee baker from fuji said that the 35mm has an f1.4 aperature and that, "that helps" with regards to autofocusing. As far as I know, cdaf cameras open the aperature to the max setting to let in more light. So I'm not sure how dof is going to factor in there.
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You were halfway to answering that question in your next statement, since an "oof background" is a (relatively) low contrast background.
Photohobbyfun said:
another thing I've noticed is that if you try to focus on an oof background, the x100 has trouble finding focus. I thibk that because it's out of focus the algorithym has trouble finding the highest point of contrast.
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A large aperture minimizes the zone (or point) of sharpest focus, which limits the zone or point of highest contrast. That makes focusing easier with any CD sensor, including those in the X100 and X-Pro1.

--
X-Pig1
 
CDAF precision is only indirectly related to CDAF speed. Of course the system must find a contrast target, in order to lock focus.

That is a problem even with the superfast CDAF of Olympus, which can fail in low light. Therefore a large aperture helps.

But in good light the AF speed willl depend on a combination of factors: processing speed of the camera, internal focussing of the lens travelling fast, micromotors.

Even if there are minor variations among the lenses, a mfr will do all it can to ensure that AF is both fast and predictable. Slow and unpredictable is instead typical of an AF system in its infancy, where lenses have not yet been optimised for FAST and/or processing is slow.

In this respect PDAF has lesser requirements than CDAF, so the lenses must be redesigned with lighter elements, different motors.

Am.
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Photostream: http://www.flickr.com/photos/amalric
 
Jon Rty said:
I hear you, but the Contax G2 wan't a rangefinder in todays sense of the word. As you of course know, there is no actual mechanical rangefinder on the camera.
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I don't know what you mean by "todays sense of the word," but the Contax G cameras were true rangefinders, in that they determined focusing distance (range) by a process of triangulation and then set the lens to focus at that distance. This is exactly how classic rangefinders, such as the Leica M series, achieve focus as well. The Gs had very fast and precise autofocus, and the Ms have slower, but equally precise manual focus, which some people seem to prefer. I'm not one of them.

In contrast, the Fuji X-Pro 1 is not a true rangefinder. It just looks like one and may provide a similar shooting experience to a Contax G2.

Rob
 
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