Alaarx wrote:
Quick question - apologies if its obvious.
Canon touts all these amazing AF changes coupled with 100% coverage, eye AF, new dual pixel tech etc etc. I assume all these features require live view which means they cannot be used through the OVF but only on the rear screen? I'd buy an SLR with these AF abilities through an optical finder in an instant.
Sorry if it's been answered its a lot of thread to trawl through.
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evertdoorn wrote:
Yep
Actually, I don't think that's true. Canon is saying that they have improved auto-focus through the OVF too. Here's what they said in their press release:
"When using the optical viewfinder the camera will use a new autofocus sensor, with approximately 28 times the resolution in the center of the EOS-1D X Mark II. Offering the ability to autofocus in even brighter and darker situations than before and with greater precision, the camera will have a range of autofocus capabilities, which will enable the photographer to get their shot. In Live View mode, users will be able to make use of 525 AF areas using the Dual Pixel CMOS AF system will cover approximately 90x100 percent of the image sensor."
I'm actually in the process of switching from Canon to Sony but only in part for Sony's AF. Mostly because for what I do, 20 fps is definitely useful and the 20 fps on the 1D3 won't be useful to me since it's Live View only.
Choderboy wrote:
My understanding of the evolving Canon metering / AF sensor:
1DIV: unknown pixels, Black and White
1DX: 100,000-pixel, RGB
1DXII: 360,000-pixel, RGB-IR.
1DXIII: unknown pixels, 28 times resolution in centre
This is the colour metering sensor as opposed to the AF sensor. The AF sensor is still 61 points, I expect they mean the new colour metering sensor could be 28x higher res in the central region, so many MP for the new colour metering sensor, should make a huge difference to subject discrimination against busy backgrounds. No longer would the subject be a low res blob. It could also help improve AF with lower contrast situations etc.
https://www.the-digital-picture.com/Reviews/Canon-EOS-1D-X-Mark-II.aspx
Exposure/Metering System
Metering systems continue to get better and the 1D X Mark II's 360,000-pixel RGB+IR metering sensor is a significant upgrade from the 1D X's 100,000-pixel RGB sensor. This new system claims improved facial and wildlife tracking capabilities and provides information to the Intelligent Tracking and Recognition (iTR) AF system and, as I mentioned above, this system works very well.
Choderboy wrote:
My understanding of the evolving Canon metering / AF sensor:
1DIV: unknown pixels, Black and White
1DX: 100,000-pixel, RGB
1DXII: 360,000-pixel, RGB-IR.
1DXIII: unknown pixels, 28 times resolution in centre
Pixel Perfect wrote:
This is the colour metering sensor as opposed to the AF sensor. The AF sensor is still 61 points, I expect they mean the new colour metering sensor could be 28x higher res in the central region, so many MP for the new colour metering sensor, should make a huge difference to subject discrimination against busy backgrounds. No longer would the subject be a low res blob. It could also help improve AF with lower contrast situations etc.
It's quite clear from the Canon PR that the AF sensor has 28x higher resolution, not the metering sensor.
"When using the optical viewfinder the camera will use a new autofocus sensor, with approximately 28 times the resolution in the center of the EOS-1D X Mark II."
EB-1 wrote:
It's quite clear from the Canon PR that the AF sensor has 28x higher resolution, not the metering sensor.
"When using the optical viewfinder the camera will use a new autofocus sensor, with approximately 28 times the resolution in the center of the EOS-1D X Mark II."
EBH
I don't think it is clear at all. 3 of my quotes above are from Canon talking about the metering sensor and say "Tracking" in 2 and "able to keep up with even rapidly moving subjects".
It's Bryan Carnathan who says "provides information to the Intelligent Tracking and Recognition (iTR) AF system"
The problem may be all the side chatter, not the press release. The sentence above was very clear. Of course the PR was preemptive after the D6 announcement and the minor update from the a9 to a9 II. The actual 1DX III may not have been finalized yet. I think it is reasonable to assume that the AF will be improved, but I suspect still not as good as the D6 will be.
How can the OVF AF have 28x the resolution. It’s still 61 AF points, and what is the resolution of an AF sensor for that matter. You could say that the AF sensors are 28x more sensitive but that’s not resolution. If it’s not related to the iTTR and is not referring to the DPAF for Liveview, then I’m not sure what they mean. AF doesn’t work on resolving a region, it works on acquiring a phase difference from the region. If the region it worked on was sqrt(28)x smaller, it’s would surely have much worse SNR and be far far finer than spot AF.
One way it could work thinking about it, is each of the central AF boxes is actually an array of smaller AF sensors and the signal is analyzed from each sub-sensor. and combined for final AF drive calculation Maybe it would help with lower contrast subjects
Pixel Perfect wrote:
How can the OVF AF have 28x the resolution. It’s still 61 AF points, and what is the resolution of an AF sensor for that matter. You could say that the AF sensors are 28x more sensitive but that’s not resolution. If it’s not related to the iTTR and is not referring to the DPAF for Liveview, then I’m not sure what they mean. AF doesn’t work on resolving a region, it works on acquiring a phase difference from the region. If the region it worked on was sqrt(28)x smaller, it’s would surely have much worse SNR and be far far finer than spot AF.
One way it could work thinking about it, is each of the central AF boxes is actually an array of smaller AF sensors and the signal is analyzed from each sub-sensor. and combined for final AF drive calculation Maybe it would help with lower contrast subjects...Show more →
Most likely scenario is that they actually mean the metering sensor has 28x the resolution which would let it do much finer subject recognition. Also, do we have any information that it has 61 AF points other than the rumor sites?
whumber wrote:
Most likely scenario is that they actually mean the metering sensor has 28x the resolution which would let it do much finer subject recognition.
That would mean the metering sensor would have to have 282 megapixels, which is very unlikely.
28x resolution may refer to finer resolution of the AF sensor, not in terms of focus points but the resolving ability of the focus sensors, i.e. it may be able to detect 28 times smaller focus errors.
ilkka_nissila wrote:
That would mean the metering sensor would have to have 282 megapixels, which is very unlikely.
28x resolution may refer to finer resolution of the AF sensor, not in terms of focus points but the resolving ability of the focus sensors, i.e. it may be able to detect 28 times smaller focus errors.
I thought the metering sensor of the 1DX II was 100K pixels (0.1 megapixels) ?
The 1DX iTR sensor is 100000 pixels. The 1DX Mark II has a 360000 pixel iTR sensor.
In the 7D Mark II, it's 150000 pixels.
The phase detect AF sensors are like linear sensor arrays. Nothing says they can't increase the resolution of these, to provide more accurate phase difference metering.
So a 28 x increase in linear resolution from 0.36 MP gives 282 MP. It is very uncommon to mean linear resolution when we speak about a two-dimensional sensor.
I guess everything is still possible, 28x AF resolution and 28x AF support sensor resolution, but not 28 x increase in main sensor resolution
