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05-12-2010, 04:50 AM   #61
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QuoteOriginally posted by blende8 Quote
So, the Kx is about 6 times slower than the EVILs in contrast AF?
It seems so yes (probably not a focus of development when flipping the mirror down got it so quick.)

And flickering mirror up and down all the time for continous auto-focus during filming don't seem like something one want to do (3600 times / minute at 60 fps? ;D) so that's no continous af on those cameras.

Was there any such numbers for the 550D/7D to?

I know it could flip down the mirror to at will but I wonder how fast the contrast-detect one is, not as fast as the Panasonic atleast.

Any numbers for the Olympus ones?

I've also understood one want different kinds of af-motors for contrast-detect autofocus.

05-12-2010, 05:03 AM   #62
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550D:
Full Autofocus
Auto Selection AF
Optical Viewfinder

0.210 second

Full Autofocus
Live View
"Quick Mode"
(Phase Detect)
w kitlens instead of the sigma since it didn't worked with sigma

0.991 second

Full Autofocus
Live View
"Live Mode"
(Contrast Detect)
1.720 seconds


So not even close...

D90:
Full Autofocus
Auto-Area AF
Optical Viewfinder

0.270 second

Prefocused
Optical Viewfinder

0.067 second

Full Autofocus
Live View
2.294 seconds


Sony got a different system so maybe they are better:

a-550 not tested, 380 is and it was quick!

Full Autofocus
Wide Area AF

0.204 second

Pre-focused

0.107 second

Full Autofocus
Single Area AF
Live View mode
0.196 second


"The nice thing about Sony's Live View implementation is that shutter lag in Live View mode is just as fast as when using the optical viewfinder. (In this case, full AF was slightly faster, at 0.196 second.) This is because the second image sensor located in the A380's viewfinder housing alleviates the need for the additional mirror flips required by most other phase-detect Live View implementations. Other phase-detect systems need to drop the mirror, focus, and raise it again to before taking a shot in Live View mode, or employ a slower contrast-detect autofocus method using the main image sensor. Since the image sensor feeding the A380's live preview is located above the mirror, the mirror stays down until the final exposure, exactly as it does in optical viewfinder mode. As noted elsewhere, though, the downside of this type of Live View implementation is lower accuracy for the Live View viewfinder display."



Oh, I thought it had some special focus device when mirror was down, not some sort of "preview-sensor" when mirror was up , so no contrast-detect I guess, just fast anyway, but won't work for video on the large sensor =P


Olympus E-P2:


Multi-area AF mode,
Telephoto
0.929 second

Rather crap ..



Oh well, so sony and panasonic contrast-detect = fast, olympus = rather poor, sony = does live-view without using contrast-detect, everyone else = slow when using contrast-detect but fast otherwise.
05-12-2010, 05:29 AM   #63
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QuoteOriginally posted by aliquis Quote
Oh well, so sony and panasonic contrast-detect = fast, olympus = rather poor, sony = does live-view without using contrast-detect, everyone else = slow when using contrast-detect but fast otherwise.
This means that Sony has no more reason for their second LV sensor design when using their Exmor HD sensor in forthcoming dSLRs.

Currently, they are the only SLR manufacturer who has demonstrated that contrast AF with an APS-C sensor can be made fast enough.

And if you remember correctly, I've always predicted that contrast AF can be made faster than phase AF. Another factor 2-4 and we're there.
05-12-2010, 07:11 AM   #64
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QuoteOriginally posted by aliquis Quote
Regarding contrast-detect focus speeds:
NEX5 focus speed:
http://www.youtube.com/watch?v=tNxPgNVDGK8
GF1 focus speed:
http://www.youtube.com/watch?v=SfgtC2kVD1o
These 2 videos are a little bit questionable...

-First, if we can guess that the Sony is using the 18-55mm (since it's not the pancake), we don't know which lens is used on the Panasonic. It can make a lot of difference since the kit lens of Sony is probably not built to be the faster focusing lens in the world.
-Then, look at the setting: the NEX5 is used at f/3.5, while the GF1 at f/5.6. Keep also in mind that Sony is using a little bit bigger sensor, then you can imagine that the DOF is quite different between these 2 systems! So it's not a surprise to see a "faster" GF1.

For all these reasons, and as I don't care to know which one is the real faster (since I don't care about EVIL), I would like to congratulate Sony for the development of an innovative and interesting (but still not perfect) new kind of camera.

05-12-2010, 07:30 AM   #65
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QuoteOriginally posted by i83N Quote
Other possibility that they will make a FF DSLR with moving back and forward sensor to change from FF to APS-C
this does nothing to change format.,

the focus plane and regestry distance remain unchanged regardless of sensor size, if the lens mount stays the same.

However a moving (back and forward) sensor does offer some interesting new design concepts.

First you could add shake reduction into the 3rd dimension, not just lateral or vertical but aolng the axis of the optical path.

second, you could add a lot more in terms of focus adjustment.
05-12-2010, 07:58 AM   #66
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QuoteOriginally posted by Lowell Goudge Quote
First you could add shake reduction into the 3rd dimension, not just lateral or vertical but aolng the axis of the optical path.
That would be pretty interesting for handheld macro photography!
05-12-2010, 10:45 AM   #67
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QuoteOriginally posted by falconeye Quote
This means that Sony has no more reason for their second LV sensor design when using their Exmor HD sensor in forthcoming dSLRs.
Currently, they are the only SLR manufacturer who has demonstrated that contrast AF with an APS-C sensor can be made fast enough.
The speed can only be achieved by specially designed lens - with significant weight reduction of the focusing group, and positioning adjustment. That's why there is no AF available at all for Alpha lens mounted to NEX via adapter!
05-12-2010, 10:51 AM   #68
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QuoteOriginally posted by nosnoop Quote
The speed can only be achieved by specially designed lens - with significant weight reduction of the focusing group, and positioning adjustment.
This statement is based on assumptions which don't hold true in general.

05-12-2010, 11:11 AM   #69
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QuoteOriginally posted by aliquis Quote

Oh well, so sony and panasonic contrast-detect = fast, olympus = rather poor, sony = does live-view without using contrast-detect, everyone else = slow when using contrast-detect but fast otherwise.
NEX-5

Full Autofocus,
Single-area AF mode
Wide Angle 0.441 second
Full Autofocus,
Single-area AF mode
Telephoto 0.444 second

Prefocused 0.115 second

GF1
Prefocused 0.072 second

14-45mm lens @14mm
Full Autofocus,
Single-area AF mode 0.473 second
14-45mm lens @45mm
Full Autofocus,
Single-area AF mode 0.402 second


NX10
Full Autofocus,
Single-area AF mode
Wide Angle 0.424 second
Full Autofocus,
Single-area AF mode
Telephoto 0.388 second
Prefocused 0.119 second
05-12-2010, 03:54 PM   #70
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QuoteOriginally posted by falconeye Quote
This statement is based on assumptions which don't hold true in general.
Check out dpreview's AF tests on Panasonic vs Olympus. The camera AF design certainly plays a major role. But the lens design made a huge difference as well - as demonstrated by Panasonic camera using Olympus lens.

And do note that those Olympus lenses were already designed with Contrast AF in mind!
05-12-2010, 04:11 PM   #71
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QuoteOriginally posted by nosnoop Quote
Check out dpreview's AF tests on Panasonic vs Olympus.
You make a generic assertion ("The speed can only be achieved by specially designed lens"). This cannot be proven by testing existing products. You would have to provide reasons and I would probably challenge them. I don't disagree that existing MILCs require specific lenses for fast AF.
05-12-2010, 08:11 PM   #72
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QuoteOriginally posted by falconeye Quote
This means that Sony has no more reason for their second LV sensor design when using their Exmor HD sensor in forthcoming dSLRs.

Currently, they are the only SLR manufacturer who has demonstrated that contrast AF with an APS-C sensor can be made fast enough.

And if you remember correctly, I've always predicted that contrast AF can be made faster than phase AF. Another factor 2-4 and we're there.
I don't know if I get the first part, but yeah, if they got a new sensor and technology for fast contrast-detect focus they don't need the mirror and second sensor, but that was kinda obvious? The question is if they will drop the mirror but keep the camera design and go EVF or whatever. Or maybe I don't get what you're saying.

They don't seem to be using contrast-af, well, if you mean in the DSLRs, they seem to be using phase-detect since they can since their live view sensor works with mirror down. If you speak of the NEX cameras then yes, but who doubted it could be made fast enough? Why would it be harder with APS-C than micro four thirds? Just throw enough bandwidth and processing power at it.
QuoteOriginally posted by youky63 Quote
These 2 videos are a little bit questionable...

-First, if we can guess that the Sony is using the 18-55mm (since it's not the pancake), we don't know which lens is used on the Panasonic. It can make a lot of difference since the kit lens of Sony is probably not built to be the faster focusing lens in the world.
-Then, look at the setting: the NEX5 is used at f/3.5, while the GF1 at f/5.6. Keep also in mind that Sony is using a little bit bigger sensor, then you can imagine that the DOF is quite different between these 2 systems! So it's not a surprise to see a "faster" GF1.

For all these reasons, and as I don't care to know which one is the real faster (since I don't care about EVIL), I would like to congratulate Sony for the development of an innovative and interesting (but still not perfect) new kind of camera.
Well, it's just two videos posted on sony alpha rumors. I haven't made them and don't say they are valid or prove anything.

Also I think speed looked rather similar even if they claimed different. Neither would be a show stopper for me.

QuoteOriginally posted by ogl Quote
NEX-5

Full Autofocus,
Single-area AF mode
Wide Angle 0.441 second
Full Autofocus,
Single-area AF mode
Telephoto 0.444 second

Prefocused 0.115 second

GF1
Prefocused 0.072 second

14-45mm lens @14mm
Full Autofocus,
Single-area AF mode 0.473 second
14-45mm lens @45mm
Full Autofocus,
Single-area AF mode 0.402 second


NX10
Full Autofocus,
Single-area AF mode
Wide Angle 0.424 second
Full Autofocus,
Single-area AF mode
Telephoto 0.388 second
Prefocused 0.119 second
You just wanted to add the NX1? Thanks, forgot about it, and yes, it seems it with the others. And IR used the same lens for their tests (where it worked.)

I saw some talk here about a Nikon MILC, and some patents from 2009:
http://www.luminous-landscape.com/forum/lofiversion/index.php/t43483.html

Must read more about it.

Last edited by aliquis; 05-12-2010 at 08:45 PM.
05-13-2010, 02:56 AM   #73
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QuoteOriginally posted by aliquis Quote
I don't know if I get the first part, but yeah, if they got a new sensor and technology for fast contrast-detect focus they don't need the mirror and second sensor, but that was kinda obvious? The question is if they will drop the mirror but keep the camera design and go EVF or whatever. Or maybe I don't get what you're saying.

They don't seem to be using contrast-af, well, if you mean in the DSLRs, they seem to be using phase-detect since they can since their live view sensor works with mirror down. If you speak of the NEX cameras then yes, but who doubted it could be made fast enough? Why would it be harder with APS-C than micro four thirds?
What I meant is ...

Sony can now make a SLR without the second sensor. It would still have a mirror as otherwise, wouldn't be an SLR but the NEX. There aren't any SLRs with fast contrast AF. Sony may be the first to make one. In some situations, it may be a desirable thing to have.

The sensor (size) plays a r˘le too. For excellent contrast AF performance, you better continuously read as many pixels as possible and this creates more heat with a larger sensor. Reading only a subset of pixels deteriorates AF performance except if the AF algorithm zooms onto a region of interest during focus. AFAIK, no APSC sensor in current SLRs can be programmed to do this. Not sure about LiveMOS here.

I may not get what you are saying though. You may think that it is easier to implement fast contrast AF in a MILC than an SLR. Well, I don't think this. Which is a reason why I came back on nosnoop's proposition that special lenses are (always) needed.

Last edited by falconeye; 05-13-2010 at 03:01 AM.
05-13-2010, 04:07 AM   #74
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Well, nothing really substantial in the interview - other than a hint to that the engineers wants to make a mirrorless camera, and why not? Engineers like challenges.
But that Pentax (Hoya) has not yet decided if they would make one.
This suggests that there are prototypes, but the engineers has not yet got the final word about making it production ready.
Hoya has not decided yet if this is the way to go. Can it sell enough to be profitable?
And what about lenses?
Engineers wants many things, but usually few of those engineering-dreams are made into a saleable product.

About "big things this year". The chief over Pentax Europe has confirmed new cameras coming this year, and it seems to be at least three DSLR's so that is quite many. (updates to K-7, K-x and a new model in-between).

If Pentax goes mirrorless, then I believe this is the last update for the entry level APS-C DSLR segment for Pentax and the future APS-C will concentrate on enthusiast to pro market, leaving the mirrorless for the entry level to bridge the gap between p&s and DSLR's.

And then we have this thing about lenses...
Well, since Pentax hasn't released any new K-mount lens for a while (the DFA 100 WR being an exterior update, same optics as before), they could switch to micro K-mount development. This means no more new K-mount lenses from Pentax, only micro K-mount.

They doesn't have the r&d and production to support many different lens mounts, not alone. They need partners!
05-13-2010, 04:35 AM   #75
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I don't see any hint that they would launch a "micro K-mount" system. They only said that, in the future, they might do it. They had similar comments about FF...
I would be very surprised if the next lenses will be "micro K-mount"; for now Hoya looks determined to complete the K-mount system. Maybe the lack of new K-mount products is due to the 645D?
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