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Messages - Don Haines

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61
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 26, 2014, 12:05:21 AM »

0-16384 (14 bit ADC) is infinity?  ???



16,384 = 2^14.

The lowest value the sensor records, however, isn't 0.

It's 2^0. Were it zero, any increase would be infinite on a percentage basis.

But it isn't.

1-2-4-8-...2^bitdepth

The range is from 0 to (2^N)-1
it is 0 to 16383

62
EOS Bodies / Re: Do Sensors sell the Camera?
« on: August 26, 2014, 12:01:12 AM »
I fully expect Sony/Nikon cameras to have 15, if not 16, bit ADCs in 4 years time.

I am amazed that they don't have them already...

The 7D has a full well charge of 24,800. you need 15 bits to properly read that.... and in the last 5 years full well charges have increased, particularly with FF. Only having 14 bits is a choke point.

The full well charge on the full-frame bodies won't even fit into 16 bits.  In an ideal world, they'd dispose of the downstream amplifier and go to at least a 17-bit DAC (or cut costs and use an off-the-shelf 18-bit DAC).

With that said, given that we're talking about an analog voltage level, they'd probably be better off using a higher-precision DAC even though strictly speaking there are fewer discrete levels, if only because you'd expect some charge decay over the course of longer shots, and having a more precise measurement of the voltage would allow you to adjust for that in post processing.

Also, there's the issue of noise floor.  You want the digital floor to be way below the analog floor so that you guarantee that anything that qualifies as signal gets captured.  Right now, the digital floor is considerably above the analog floor (as you pointed out), which is bad.  Pushing it several bits below makes for a nice safety margin.

Personally, I don't really understand why all the camera manufacturers don't just standardize on a 20-bit DAC and be done with it.  Storage is cheap.  Quality is irreplaceable.  Why cut corners?
I know.... it's not like it's hard to do....
I can't think of anything at work that does not use at least 24 bit A/D and we have some test equipment that has 64 bit A/D and others that have 48 bit A/D running at 60Ghz sampling rates... I think that the last time I designed something with only 16 bit A/D was back in the 1980's....

63
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 11:53:17 PM »
I've never been too sure about putting ML on a brand new camera.
+1

I intend to get a 7D2 when it comes out. I really don't care about any of the features other than the AF system as I am sure that everything will be an improvement over the 60D. The first thing I do when it arrives will be to send my 60D off to Canon for a cleaning and a new rubber grip.... The first thing I will do when it comes back is to load ML on it...

64
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 11:48:12 PM »
Don, when people show no respect and just shout and argue over everybody, it becomes impossibly difficult to show them any respect in return.
It's a hard thing to do. I try to focus on the good things and ignore the bad.... after all, we all do stupid things from time to time..

I'd love the most verbose people to actually take the time to photograph a step wedge, it should take about 15 seconds, and post their results.
I had one back in the good old days of the B+W darkroom.... I kind of wish I had one now because this has gotten me very curious as to how my various cameras compare... I might have to order one :) (any recommendations?)

Please correct me if I am wrong, but I always thought of "stops" as an analog/perception scale and that it did not necessarily match up with a digital scale... perhaps part of the confusion here is that people are talking about two different things yet using the same terminology.

65
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 11:24:05 PM »
...I started seeing this fundamentally mocking behavior.

Yep, it's just popping up all over the place!

I wish that all parties would try to be more civil and resist the urge to sink to the bottom. This forum is what we make of it....

and some advice from mom.... "Just because Timmy is an a**hole, that doesn't give you the right to be one". Keep it clean and respectful please....

66
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 10:47:04 PM »

* Stop arguing in this thread
* Do a Google search.
* Read and watch some of the many excellent tutorials out there.
* Download some HDR demo software.
* Go out and photograph some HDR scenes.


You might want to take a peek at the end of the "Beautiful sunsets" thread...
http://www.canonrumors.com/forum/index.php?topic=8105.500

67
EOS Bodies / Re: Do Sensors sell the Camera?
« on: August 25, 2014, 09:56:36 PM »
I fully expect Sony/Nikon cameras to have 15, if not 16, bit ADCs in 4 years time.

I am amazed that they don't have them already...

The 7D has a full well charge of 24,800. you need 15 bits to properly read that.... and in the last 5 years full well charges have increased, particularly with FF. Only having 14 bits is a choke point.

68
Landscape / Re: Beautiful sunsets
« on: August 25, 2014, 09:10:00 PM »


HDR merge, 5-frame, 2-stop separation.

Canon 5D III + EF 16-35mm f/2.8 L II @ 32mm
WOW!

69
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 08:12:18 PM »
So what are the engineering considerations involved in on-sensor ADC?
This is VERY! simplified, but here goes....

When you look at a 500 nanometer process and pixels that are 4000 nanometers square, your lithography is only capable of 64 (8x8) blocks to draw circuitry inside that pixel.... and don't forget that when you draw a line you need space on each side of it! If you consider that the pixel has a border, then that means that there are only 36 (6x6) blocks left... that means that you are starting your sensor design  with only 36/64 or 56 percent of your surface area usable.

And this is almost certainly the reason why Canon currently has the A/D circuitry on the external DIGIC chips.... there is not room on the sensor to do anything else.....

If you improved your lithography to 125 nanometers, then your pixel is made up of 1024 blocks (32x32) and after the border, you are left with 900 (30x30) blocks left to create your pixel. This means you are now starting your pixel design with 900/1024 or 88 percent of your surface area usable and it allows you to create far more complex circuitry.

Now go to 60 nanometers, then your pixel is made up of 4096 blocks (64x64) and after the border, you are left with 3844 (62x62) blocks left to create your pixel. This means you are now starting your pixel design with 3844/4096 or 94 percent of your surface area usable and it allows you to create even more complex circuitry.

We do not yet know the technology used on the 70D, but when you consider that if the 500 nanometer process was used, each half of the pixel would be 32 (4x8) blocks and after the border 12 (2X6) blocks, or 38 percent of the surface area usable.... and you would still have to find space to put in the more advanced electronics to handle DPAF.... that it is a certainty that the 500 nanometer process is not used here....

What this tells us is that Canon is in the process of moving to finer lithography... we just don't know how far they are going to go and what will be moved over from the Digic chips and what timeframe.... but it is happening!


70
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 07:15:21 PM »
So what are the engineering considerations involved in on-sensor ADC?
The big one is making the transistors small enough so that everything will fit.
The next big one is dealing with heat.... more heat gives you more noise....

Both considerations demand that Canon switches to a finer lithography..

71
EOS Bodies / Re: Do Sensors Make the Camera?
« on: August 25, 2014, 07:11:29 PM »
Saying that the sensor makes the camera is as silly as claiming that the engine makes the car....

Point in case.... my brother has a 1969 Dodge charger with a 650HP engine. I drive a Mazda3 with a 150HP engine..... his car has 4 times the engine mine does, yet if we took the two of them to the local track (a nice road track with lots of twists and curves) I could run away from him with ease...

You have to look at the entire package in the context of what you want to do... you can not fixate on a single component.

72
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 06:57:16 PM »
i'm pretty confident the 7D successor will deliver in AF and sport department, i just really hope it will also deliver some improvements in ISO department. Digic6 should bring something to the table, hoping for 2/3 - 1 stop ISO improvement over 70D.

Digic can't improve high ISO (unless you mean in cam jpgs and the NR algorithm)

I think the DIGIC chips do the A to D conversion.  If so, a better, lower noise conversion could help with high ISO performance.
You are correct.

A/D is done on the Digic chips and that is the reason for Canon's noise problems.

Much of the competition does the A/D on the sensor. It is better because:
On sensor A/D means no analog lines across the circuit board to pick up noise.....
On Sensor A/D can be done for an entire row or column at a time, and that means a thousand (or more) times the time to do it in, which leads to greater accuracy and less noise...

73
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 06:51:57 PM »
Well...to each is own, I guess. Me, I'm going to get vocal about Canon's crappy low ISO noise, and do everything I can to back up my claims with concrete, visual evidence...because, it's really freakin NASTY noise. STILL nasty...after all these years. And I think that needs to change (especially because Canon is still my preferred brand...I'd rather have a 5D IV with 50mp and 14 stops of DR than a D800.)

I see nothing wrong with jrista complaining about "Canon's crappy low ISO noise". It does not make him more or less of a fanboy, it just means that he isn't blind.


74
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 03:25:52 PM »
Fixed LCD, with no touch function.

I currently use a EOS 70D.  I like the articulating LCD and touch function (especially for choosing
a focus point during video recording).  Why would the 7DmII not have these features?

Don't believe it one way or the other until an official announcement is made. These rumours are just guesses...

75
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 25, 2014, 03:23:22 PM »

it's amazing how some here think they know better than a company that literally spends billions in R&D per year.

+1

allow me to slightly change your statement:

it's amazing how, based on unsubstantiated rumours, some here think they know better than a company that literally spends billions in R&D per year.

It's also amazing how they can use the fact that Canon is one of the world's largest filer of patents to show that they are not innovative....

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