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why doesn't 5DmarkII have 50D's 9 cross AF sensor?

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Past evidence would seem to indicate that they will not increase MP to such an extent that noise gets worse. There might be minor fluctuations but as far as I recall no Canon or Nikon DSLR lost as even as much as a stop in high ISO performance from one generation to the next. By all means prove me wrong with an example if I've overlooked something. And there are obvious cases where MP goes up and noise goes down, e.g. 5D -> 5DII.

So, if they did put 30MP in 5DIII, I think the answer is yes, noise would still be under control.

Will they ever stop? It's not clear why they should. It you had an 80MP sensor with per-pixel noise identical to the 5DII, it would be amazing. You might not be able to print large enough to appreciate it, or you might have to wait for monitor technology to catch up, or buy a huge RAID array, but by any objective measure, IQ would be through the roof.
RalphDurst said:
But how much megapixels will they try to cram in once again ? 30 ?
will noise still be under control ? will they ever stop ?
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What's with the hostile tone?

Dude, the industry has changed. Competition demands rapid enhancement/upgrade cycles. Just look at the changed in digital camera technology in the last decade.

Canon has, upon each successive release, improved upon their AF systems... until now. It is more than reasonable for people to question Canon's decision to not upgrade the AF of the 5D considering the AF changed from the D60 > 10D> 20D etc. It is also reasonable for people to question why Canon didn't do something more to compete with the AF offerings from the new crop of Nikon cameras.

Ever since the 5D came out, a lot of people have been saying "it's a great camera but I wish the AF was better/faster". Canon had a huge opportunity to rectify this situation. I disagree with the idea that all of Canon's techs are working on the new AF for the MkIV. All Canon had to do was to put in the excellent but "dated" AF from the MkII and people would have been thrilled.

I think Canon released a great upgrade to the 5D but dropped the ball with the AF.
RedFox88 said:
So that's 9 years between AF upgrades and you're
whinning over 3 years without an upgraded AF?
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--
Ken W.
http://www.arc-photo.com
http://www.quantumarts.com
 
... your post was tongue-in-cheek.

I photograph architecture but enjoy using my camera to take pics of my neices and nephews and new puppy, all of whom are ACTIVE. I don't want to have a separate camera for this.

Let's face it. Canon dropped the ball with the AF. Great upgrade except for the AF. Why change so much and not improve upon this one thing that people have been begging for? As I stated in a previous post, all Canon had to do was to put in the AF from the 1D Mk II series and everyone would have been thrilled. That system is highly regarded but considered a bit dated now that it has been "upgraded". Canon wouldn't really have to do any new dev and voila, mose would have been happy.
--
Ken W.
http://www.arc-photo.com
http://www.quantumarts.com
 
Karma Traveler said:
RayDee said:
In my opinion, what's worse than the lack of cross sensors is the
clustering of the af points around the center.
Click to expand...
The 5Dmk2's AF points are no more clustered towards the center than
the 1Dsmk3's. In fact, if you overlayed the AF points of the 1Dsmk3,
5Dmk2, A900, and D700... you'll see that they are all equally
clustered towards the middle.

It's a technological limitation for full frame digital SLRs of any
brand. It has nothing to do with the 5Dmk2 specifically.

The 5Dmk2's AF system is fine. The new Sony A900's AF system is
nearly identical to it --- but you don't see the Sony folks whining
as loudly as the Canon crybabies.
Click to expand...
Ummm, because Sony doesn't keep any better AF system from them because of the market segmentation?
Karma Traveler said:
The only reason people keep
whining and crying and moaning is because the 5Dmk2's AF system isn't
as good as Nikon's.
Click to expand...
Or because it isn't better than the OLD 1D Mk2 AF system...
Karma Traveler said:
Before the D3/D300/D700 came along, you rarely
ever heard anyone complain about "poor" or "inadequate" AF on the 5D.
But once those Nikon cameras showed up, people started whining and
crying and moaning.
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So what? That's competition.
Karma Traveler said:
I think 99.99% of complaints only started on the
day the D300 was announced.
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And why it was so? Because someone showed that not only the high-end pros are entitled to the pro AF system. Prosumers having pro AF, heavens forbid! Someone at Canon HQ got a heart attack perhaps, because it looks like if there is a Canon bible, surely "Thou shalt not give thy prosumers a pro-AF system of any kind" is written down there.
Karma Traveler said:
There is nothing inherently wrong with the 5D's AF system. But it is
not as good as Nikon's. That's the only sin it's guilty of.
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No, the sin is with the creator: He could recycle the "old" 1D2 AF and put it into the 5D2. I highly doubt that 1) they lost the blueprints 2) it would raise the cost significantly.

--
Cheers,
Martin

 
It is possible and likely that liveview AF is quite usable for many types of scenes in which ONE SHOT AF would be used. It appears that with LiveView, you can focus on any point of the frame, not just one of the focus points. Sure it is slower, but it can be more accurate due to the extreme maginifcation you can get in the LCD.

Also, I'm willing to bet that with USM lenses, you can nudge the focus manually to a point near where you want and let the contrast detect AF fine tune it very quickly. Most importantly, this can be any point on the shot and apparently isn't limited to small areas covered by the traditional AF points.

--
http://www.thomasarts.com (company website)

http://gallery.me.com/thomasarts (company photo working gallery)

http://gallery.me.com/mthomas (personal photo gallery)
 
That's really a strange logic and probably just some marketing bs. 50D is the camera for action shots and 5D the one for landscape/portrait. The inability to use the outer AF points with large aperture lenses is going to handicap 5DII's ability to claim itself as the ultimate portrait camera.
Jamie H. said:
Either way, I think its kind of sad they couldnt improve on the AF of
the 5D after three years.
Thomas K. said:
40D and 50D both have the "new" AF system with 9 AF points having
cross sensor. meanwhile the 5D mark II still keeps the 1 cross sensor
in the center and has 8 points which are not cross type. any reason
for this? any vantages?

so far i couldn't find an answer here on the forum.
regards
thomas

--
visit my homepage http://thomas.im
portrait - studio - streetlife
Click to expand...
--



Amateurs worry about sharpness
Professionals worry about sales
Photographers worry about light

http://archive.jmhphoto.net
Click to expand...
 
You think there are more people shooting sports with 5D2 and portraits with 50D than the other way around? I'm not going to buy 5D2, at least not this year, but I just can't stand the thought that I will need to put every head shot right in the middle of the frame when I shoot 85L wide open with 5D2.
Amin Sabet said:
I think it's fair to say, based on available data including Chuck
Westfall's comments, that the 50D 9 cross-type sensor AF is better
for static subjects and the 5D II system is better for tracking
dynamic ones. It's a shame that they couldn't combine the two. 9
cross point sensors with 6 assist points around the center would have
been a compelling system for the 5D II without encroaching on the
Canon 1 series capabilities.

--
-Amin
Click to expand...
 
carlk said:
The inability to use the outer AF points with
large aperture lenses is going to handicap 5DII's
Click to expand...
Huh? The difference between the outer points between the 50D and the 5D2 is simply that the 50D sensors are cross types. That means the 50D versions are sensitive to detail in both directions while the 5D2 are sensitive to only one direction. This doesn't affect AF accuracy, just what type of detail will get a lock. You don't have to change the focus point or aim to compensate, you just have to tilt the camera and recompose.

--
Erik
 
Karma Traveler said:
Jamie H. said:
While the 5DII only gets on cross type sensor? I'm struggling to
make sense of this.
Click to expand...
I also wish the 5Dmk2 had more cross type AF points. Maybe Canon has
its hands full trying to figure out the 1Dmk3 AF issues in
preparation for next year's 1Dmk4. Maybe they just didn't want to
divert resources for a new AF system for the 5Dmk2.

But people keep assuming that the 5D/5Dmk2 AF system is a step down
from the 50D's. I'm not so sure it is.

50D: 9-pt AF System, 1 High Precision, 9 Cross Type.

5Dmk2: 15-pt AF System, 3 High Precision, 1 Cross Type.
Click to expand...
This isn't correct, 5DII does NOT have the dual 45 degree sensors at center it only has a third horizontal sensor so at f/2.8, 40/50D center point has higher precision than 5DII.

Also two of the assist points are active at f/2.8, they are only horizontal and NOT high precision, not even cross type. So on paper 5DII AF is inferior to that of 40/50D, however tracking might be better because of the assist points. but still Canon could have kept the assist points and changed the rest of the sensors to cross type, which they did not.

see this
http://forums.dpreview.com/forums/read.asp?forum=1032&message=29355216
Karma Traveler said:
People like Rob Galbraith seem to think the 3-year old 5D is still
more reliable with autofocus than newer consumer-level models like
the 40D.
Click to expand...
 
Cross points and high-precision segments are different concepts.

--
Erik
 
single horizontal or vertival = 1X precision

horizontal+vertical= cross type = 2X precision

cross type + extra horizontal = 3X precision (5DII)

cross type + dual 45 degree = 4X precision or "high precision" according to Canon 40D white paper

See Canon white papers for defination
Erik Magnuson said:
Cross points and high-precision segments are different concepts.

--
Erik
Click to expand...
 
Erik Magnuson said:
carlk said:
The inability to use the outer AF points with
large aperture lenses is going to handicap 5DII's
Click to expand...
Huh? The difference between the outer points between the 50D and the
5D2 is simply that the 50D sensors are cross types. That means the
50D versions are sensitive to detail in both directions while the 5D2
are sensitive to only one direction. This doesn't affect AF
accuracy, just what type of detail will get a lock. You don't have
to change the focus point or aim to compensate, you just have to tilt
the camera and recompose.

--
Erik
Click to expand...
 
Rcihardc said:
This isn't correct, 5DII does NOT have the dual 45 degree sensors at
center it only has a third horizontal sensor so at f/2.8,
Click to expand...
You were doing so well.....
Member said:
40/50D center point has higher precision than 5DII.
Click to expand...
Nope, they have the same precision (e.g, 1/3 DOF), it's just the 40D/50D sensor can detect both vertical and horizontal detail in high-precision while the 5D sensor can only see vertical detail this way.
Member said:
Also two of the assist points are active at f/2.8, they are only
horizontal and NOT high precision, not even cross type.
Click to expand...
You are confusing the two concepts. The f/2.8 segments are higher precision because they can use a longer baseline for AF calculations. This has nothing to do with the orientation or crossing. (The other potential difference is the pixel pitch of the sensors. A finer pixel pitch can in theory also give somewhat higher precision.)

--
Erik
 
Use the same (outer) focus point and just tilt the camera if all of the detail is parallel to the sensor. You will not be changing the effective angular distance.

--
Erik
 
Erik Magnuson said:
Rcihardc said:
This isn't correct, 5DII does NOT have the dual 45 degree sensors at
center it only has a third horizontal sensor so at f/2.8,
Click to expand...
You were doing so well.....
Member said:
40/50D center point has higher precision than 5DII.
Click to expand...
Nope, they have the same precision (e.g, 1/3 DOF), it's just the
40D/50D sensor can detect both vertical and horizontal detail in
high-precision while the 5D sensor can only see vertical detail this
way.
Click to expand...
Read the Canon white paper, only EOS 40/50D (among all EOS cameras) have 45 degree center sensor, 5D DOES NOT have 45 degree sensor.
Member said:
Member said:
Also two of the assist points are active at f/2.8, they are only
horizontal and NOT high precision, not even cross type.
Click to expand...
You are confusing the two concepts. The f/2.8 segments are higher
precision because they can use a longer baseline for AF calculations.
This has nothing to do with the orientation or crossing. (The other
potential difference is the pixel pitch of the sensors. A finer pixel
pitch can in theory also give somewhat higher precision.)
Click to expand...
Sensor does not perform any calculation, it is just a phase spliter like an interferometer, horizontal and verical are the same only monuted in different orientation-see the chip diagram , there is no difference between the f/2.8 sensors and the rest. Canon certainly doesn't call them high precision.
Member said:
Erik
Click to expand...
 
Rcihardc said:
cross type + dual 45 degree = 4X precision or "high precision"
according to Canon 40D white paper

See Canon white papers for defination
Click to expand...
I have. Here is a copy of the table from the 40D white paperL



The term 4X precision is not used anywhere in that paper.

--
Erik
 
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