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Author Topic: 5D Mark III [CR1]  (Read 46627 times)

hlphoto

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Re: 5D Mark III [CR1]
« Reply #15 on: May 20, 2011, 11:48:05 AM »
Why would Canon create a new sensor that wouldn't go past a native 3200 ISO after having one that does a very nice ISO 6400 (5D Mk2)?

When you start having more than one value in the raw file per electron in the sensel, it does not make much sense to increase the amplification further, you can just scale in software. Unity gain (1 raw value = 1 electron) happens quite early, say around ISO 1600 or so. Why some cameras still do "native" amplification past unity gain I don't really know, perhaps there are some read noise advantages or something.
Not sure what this means exactly, can you explain further? >> My experience is that when you pitch up in software you lose lots of dynamic range, same as when you pitch downward. ISO 50 on the 5D Mk2 gives me exactly one stop less headroom then the same picture has at ISO 100. If they would make a 5D Mk3 with native ISO 1600 which would go up to ISO 25600 (=H4), that would mean I lost 4 stops of DR in my image. Not very nice..

Of course, if I am missing something technically, please do explain! Always willing to learn :)

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Re: 5D Mark III [CR1]
« Reply #15 on: May 20, 2011, 11:48:05 AM »

motorhead

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Re: 5D Mark III [CR1]
« Reply #16 on: May 20, 2011, 12:09:30 PM »
Unlike others, I'm all in favour of as many mp as possible.

Me too :-). I think 40 - 60 megapixels would be ideal for full-frame 36x24mm sensors. Past that the sensor is too small to support it well, and resolution will be higher than needed for most applications. I'd like to be able to produce pictures that can fill a book spread at glorious 400 ppi, which current full-frame cameras can't because resolution is too low. If you shoot detailed landscapes today you'd want a medium format system, which of course are way too expensive for hobbyists. Anyway 32 megapixels is a step in the right direction from my point of view.

I read an interesting article on medium format sensors the other day. In it was a discussion on how many mp would be needed before the sensor outperformed the lens. Apparently Canon are said to be working on lenses for 36x24 "full frame" that will work happily up to 60mp, while on the Pentax 645 sensors would need to exceed 110mp before it becomes an issue. Basically, I believe that manufacturers will simply offer better lenses as the MP count creeps ever higher.

That same article was saying that in prints of A3 or bigger, the large MP sensors on good quality medium format systems produced a very obvious quality improvement over the 36 x 24mm "full frame" size sensors. Basically, bigger is still always better.

torger

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Re: 5D Mark III [CR1]
« Reply #17 on: May 20, 2011, 12:15:31 PM »
Why would Canon create a new sensor that wouldn't go past a native 3200 ISO after having one that does a very nice ISO 6400 (5D Mk2)?

When you start having more than one value in the raw file per electron in the sensel, it does not make much sense to increase the amplification further, you can just scale in software. Unity gain (1 raw value = 1 electron) happens quite early, say around ISO 1600 or so. Why some cameras still do "native" amplification past unity gain I don't really know, perhaps there are some read noise advantages or something.
Not sure what this means exactly, can you explain further? >> My experience is that when you pitch up in software you lose lots of dynamic range, same as when you pitch downward. ISO 50 on the 5D Mk2 gives me exactly one stop less headroom then the same picture has at ISO 100. If they would make a 5D Mk3 with native ISO 1600 which would go up to ISO 25600 (=H4), that would mean I lost 4 stops of DR in my image. Not very nice..

Of course, if I am missing something technically, please do explain! Always willing to learn :)

In photography, you want to gather as much light as possible to get the best image quality. "Expose to the right" is the concept used when you are not restricted with the shutter, that is you can saturate the sensor (without overexposing important features of course).

The reason why more light equals better image quality is because light contains noise naturally (photon shot noise), but the stronger the light the smaller part of it is noise. If you reduce light with 1 stop, photon shot noise increase with 0.5 stop - the less light the lower signal-to-noise ratio.

ISO setting does not alter the sensor in any way, it only changes the amplification at readout. If we had readout electronics that precisely could count the number of electrons in each pixel/sensel, we would not need to have a ISO setting at all. It may happen in the future that the cameras will be "ISO-less".

Anyway, when you shoot high ISO it is because you need to have short shutter speeds and then we will not fill up the pixels with light, so we get more photon shot noise. Actually, the noise you see in high ISO pictures is typically dominated by shot noise, not noise from the electronics.

The sensor pixels are not perfect either though, not all photons that hit it becomes translated to electrons, so with improved efficiency of that (quantum efficiency), noise levels would be reduced for low light photography.

Yes if you multiply in software you lose dynamic range. But past unity gain it makes no difference, you've already lost the range. If your RAW value is in the range 1 - 16384 you still cannot represent 16385 electrons if your gain is >1. It could be some practical difference anyway, there must be some reason why they usually amplify past unity gain, but I don't really know why. Perhaps someone else can help us on that...

Sdiver2489

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Re: 5D Mark III [CR1]
« Reply #18 on: May 20, 2011, 01:27:17 PM »
Only because of the high-ISO settings it already sounds like a bunch of crap to me.
Why would Canon create a new sensor that wouldn't go past a native 3200 ISO after having one that does a very nice ISO 6400 (5D Mk2)?

I would bet a few dollars on the 5D Mk3 having 19-point autofocus and native ISO 12800 (with at least H2 for 51200 ISO).

I'm hoping we'll get RAW video and maybe even 2K or 3K, but do realise most dreams won't come true ;)

Uh, I'm pretty sure the way its written is showing its native ISO range. It then states there is the typical "expanded" ISO range. L1 = ISO 50 H1 = ISO 51200 H2 = 102,400 H3 = 204,800

Of course this could still be a random rumor made up by a fan, but I don't think he was implying the camera would only go natively to ISO3200

Justin

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Re: 5D Mark III [CR1]
« Reply #19 on: May 20, 2011, 02:10:10 PM »
32MP? Where am I gonna put all these images into? I just went to Rome for 6 days and I've taken over 64 GB of images! I guess I will need two new 3TB hard disks along with this 5DIII (one for original and one for backup).

I don't mind if Canon will keep it at around 24-27 MP range. I would like to see the noise performance of the current 5DII at ISO 3200 at, say, 6400 or 12800 of the new 5DIII.

Sounds like a great trip, but I don't understand why people who want to take a thousand pictures on a trip don't do so with an s-raw setting or a smaller jpg format.

For every 100 shots I take, I immediately trash half (composition, exposure, focus are all factors). A day or two later I trash half of the half (sorting for something memorable or artistic). Then a year later I'll kill another half (looking for something I haven't shot before, in a way that says something). So about a dozen shots for every hundred, and that's probably being generous with the quality of my work.

I welcome 32 mpx files. Hell I wish I could afford an 80 mpx back and camera system. You cannot have too much detail. You CAN take too many photos.
« Last Edit: May 20, 2011, 03:16:36 PM by Justin »

Justin

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Re: 5D Mark III [CR1]
« Reply #20 on: May 20, 2011, 03:25:00 PM »
I welcome this rumor of a prototype becoming not a rumor and becoming an actual product. All these delays are doing is giving me more time to research and collect resources for other gear. I've tried the Pentax 645. Really a neat system. Beautiful output. Very big investment; I'd have to sell my Canon system. I've tried the GH2. Neat little camera. I don't know that I'd be satisfied with it being my primary system, but am seriously considering it as a contender for a trip at the end of the summer. There are rumors of new Olympus and Panasonic products forthcoming, including fast lenses and new bodies with new sensors. They are rumored to be released in June. I can't wait to see what June holds.

Meanwhile, Canon is stuck. They can't even release all the products announced 9 months ago (8-15, 300, 400). Let alone those announced in February (500, 600, 200-400). The 1Ds series missed its target release date last year. The 1D is a compromise many don't want to make. 5D2 is fun and still the best thing on Canon's plate, but old, compromised tech. The 7D is second best, but aps-c. The 600D is nicely spec'd, but nothing new.

The longer it takes Canon to get it together, the more opportunities I have to decide to augment my tools, or abandon my current tools altogether.

Fine by me.
« Last Edit: May 20, 2011, 04:30:47 PM by Justin »

lee_hom

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Re: 5D Mark III [CR1]
« Reply #21 on: May 20, 2011, 03:49:48 PM »
It was stressed that below is one prototype, and two others exist.

Translation: "I made this up and emailed it to CR, and I'm covering my butt in case my wild-ass guess is completely off base."

 very true 8)

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Re: 5D Mark III [CR1]
« Reply #21 on: May 20, 2011, 03:49:48 PM »

hlphoto

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Re: 5D Mark III [CR1]
« Reply #22 on: May 20, 2011, 05:05:56 PM »
Only because of the high-ISO settings it already sounds like a bunch of crap to me.
Why would Canon create a new sensor that wouldn't go past a native 3200 ISO after having one that does a very nice ISO 6400 (5D Mk2)?

I would bet a few dollars on the 5D Mk3 having 19-point autofocus and native ISO 12800 (with at least H2 for 51200 ISO).

I'm hoping we'll get RAW video and maybe even 2K or 3K, but do realise most dreams won't come true ;)

Uh, I'm pretty sure the way its written is showing its native ISO range. It then states there is the typical "expanded" ISO range. L1 = ISO 50 H1 = ISO 51200 H2 = 102,400 H3 = 204,800

Of course this could still be a random rumor made up by a fan, but I don't think he was implying the camera would only go natively to ISO3200
Does make more sense to me, didn't read it that way. 204800 ISO is a little bit over the top if you ask me, but  well ok ;)

As for the story about photon shot noise: Not sure if I agree, but don't have enough knowledge to argue either. Waiting for deeper explanation! :)

dash2k8

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Re: 5D Mark III [CR1]
« Reply #23 on: May 20, 2011, 06:02:29 PM »
I don't understand why the burst rate is so low. 7 or 8fps would be glorious.

Picsfor

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Re: 5D Mark III [CR1]
« Reply #24 on: May 20, 2011, 06:05:13 PM »
The 204k H3 iso setting is how I read it.

I'm mainly interested in better focusing & better low light IQ.
32mp - not my first option for an upgrade but I'll live with it.

Otherwise, not too fussed - as always, I'll believe it when I see it...

unruled

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Re: 5D Mark III [CR1]
« Reply #25 on: May 20, 2011, 06:22:22 PM »
I don't understand why the burst rate is so low. 7 or 8fps would be glorious.

pushing 32MP is a lot of data, so burst rates that high would be pretty tough.

fotoray

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Re: 5D Mark III [CR1]
« Reply #26 on: May 20, 2011, 07:07:18 PM »
I don't understand why the burst rate is so low. 7 or 8fps would be glorious.

pushing 32MP is a lot of data, so burst rates that high would be pretty tough.

A higher burst rate could be accomplishing using dual Digic V processors like the 7D uses dual Digic IV.  This is how the 8 fps burst rate is achieved in the 7D.  Even so, the 5D is primarily a landscape camera so burst rate is a much lower priority, whereas the 7D is a sports/widlife camera where burst rate is much more important.   
5D Mk III | 7D | 20D | EF-S 10-22 | EF-S 17-85 | EF 17-40 f/4L | EF 24-105 f/4L | EF 70-300 DO | EF-S 60 macro | EF 100L macro | 580EX II | RRS Series 2 tripod | plus many gadgets |

Blaze

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Re: 5D Mark III [CR1]
« Reply #27 on: May 20, 2011, 07:11:04 PM »
I don't understand why the burst rate is so low. 7 or 8fps would be glorious.

pushing 32MP is a lot of data, so burst rates that high would be pretty tough.

A higher burst rate could be accomplishing using dual Digic V processors like the 7D uses dual Digic IV.  This is how the 8 fps burst rate is achieved in the 7D.  Even so, the 5D is primarily a landscape camera so burst rate is a much lower priority, whereas the 7D is a sports/widlife camera where burst rate is much more important.   

At 32 MP they could implement an 8 MP 2x2 pixel binning mode. Even if shooting in full resolution is only 4 fps, with pixel binning they could easily push it to 8 fps. That size and rate would be perfect for me when shooting sports.

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Re: 5D Mark III [CR1]
« Reply #27 on: May 20, 2011, 07:11:04 PM »

dilbert

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Re: 5D Mark III [CR1]
« Reply #28 on: May 20, 2011, 07:24:03 PM »
What I'm really curious about is at what price point they will introduce it at.

nex-s

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Re: 5D Mark III [CR1]
« Reply #29 on: May 20, 2011, 08:55:29 PM »
I just don't see the point of 32Mp. Why spoiling the burst rate because of this? Such an MP count would just momentarily fill up memory cards and your PC. And as someone mentioned before, shooting with sRAW does not work with some software. With such specs it actually seems dissapointing, because of only increased MP, ISO and AF. One of the previous topics clearly showed that between ISO, FPS, autofocus points and raw video, increased MP was the last thing people wanted. 24MP would still be ok and would give a much better FPS performance.

And if these were the only improvements Canon makes to the camera, which I doubt it will be, then I thing most of us will be very dissapointed.

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Re: 5D Mark III [CR1]
« Reply #29 on: May 20, 2011, 08:55:29 PM »