August 28, 2014, 07:08:13 AM

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Messages - Don Haines

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16
EOS Bodies / Are you planning to purchase a 7D2
« on: August 27, 2014, 10:24:52 AM »
With all the hype on the forum about the 7D2, the question is asked.... "Are you going to get one"?

Who is serious about the camera and who is just kicking tires or wondering about Canon's possible plans for the future?

17
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 27, 2014, 08:26:32 AM »
The CR guy is laughing all the way to the bank  ;)

The CR forum page on my monitor does not have any advertisement.  :P

Otherwise, yes, 48 pages of comments for the 7D2 rumor is quite something. Is this perhaps the most discussed rumor on CR forum ever? :) Shows many folks have high hopes on the new (rumored) sensor technology....
Definitely an indication of pent-up demand..... I wonder how many will purchase one?

18
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 26, 2014, 10:30:08 PM »
I believe that a lot of pros are more impressed with a camera that does the job with no surprises than the latest whiz-bang feature....

And if you look at Canon, an awful lot of new technology and features get introduced in Rebels and P/S cameras so the masses can "debug" them before it goes to pro or semi-pro level cameras.... and when they eventually make their way to the pro level cameras they are solid.

19
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 26, 2014, 10:25:17 PM »
Yeah Canon may eventually add 4k. That just shows Canon is no longer an innovator, just a  follower.
Sometimes when you are following someone and they go off a cliff, it's a good thing that you had time to stop.....

20
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 26, 2014, 07:23:31 PM »
Most buyers will be looking for integrated imaging devices, not specialized stills or video cameras.

Indeed.  That explains why everyone has one of these:



I cringe when I see those. It is a tool that does nothing well and usually leaves a mess behind....

21
EOS Bodies / Re: Do Sensors Make the Camera?
« on: August 26, 2014, 04:37:42 PM »
and that means the split pixels it does not improve the file quality.

That's not what he was getting at. He's saying (I believe) they already have a finer process, and citing DPAF as proof, even though they currently are using it for something other than IQ.

Well, to be fair, he is still speculating about the 70D being made with a 180nm process. The 70D has only a few extra gates to handle the ability to read the two separate photodiodes in each pixel separately, as well as to bin them for a full pixel read. There isn't even a 10% increase in pixel FWC...if they had moved to 180nm, that means the border of wiring and transistors around each pixel would shrink by 320nm each side. That would lead to an increase in photodiode area of nearly 43%. Even assuming the independent read and binning logic takes up more space, I would still have expected more than a 9% increase in FWC if the 70D had moved to a 180nm process.
If they had done DPAF on the 500nM process, I would have expected the FWC to have dropped... yet, as you point out, it has slightly gone up...

of course, all this is speculation..... I have no inside information and am just guessing at a possible scenario....

22
EOS Bodies / Re: Do Sensors Make the Camera?
« on: August 26, 2014, 04:32:55 PM »
and that means the split pixels it does not improve the file quality.

That's not what he was getting at. He's saying (I believe) they already have a finer process, and citing DPAF as proof, even though they currently are using it for something other than IQ.
Yes!
With the available space on the die, I believe that there is not enough space to build the circuitry required for DPAF for the 70D using the 500nM process...

23
EOS Bodies / Re: Do Sensors Make the Camera?
« on: August 26, 2014, 03:09:54 PM »
Why is a cooperation like Canon not making a new sensor fabrication?

A new CMOS production line worth at least twenty million dollars. Without enough motivation, a old school cooperation is very unlikely to spend this kind of money on things like that. Therefore, the company decided to work the engineers' buds off to push the limit for the old 500nm sensor because it is cheaper.

The best reason that I can think of as to why they are not buying a new CMOS production line is because with the downturn in P/S camera sales, production capacity is opening up on their existing production line for small sensors, which is a finer line than that used for FF and APS-C (Non DPAF) sensors.

The second point to make is that the complexity of circuitry required to make a DPAF 70D sensor is beyond that which can be fabricated on the 500nM line... therefore, it must be fabricated on something else and that means the existing fabrication line for P/S sensors.... This means that they are now in the process of switching over to a finer line and when that is done, they can shut down the 500nM line and save money..... because it costs more to keep 2 lines running than 1 line.

24
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 26, 2014, 02:33:19 PM »
Concerning heat dissipation, why not a Peltier unit affixed to the sensor assembly?

Extremely power hungry, you have to get the heat out somewhere (often a finned heat sink with a fan), very expensive.

For example:


http://www.atik-cameras.com/products/info/atik-4000

A peltier device adds heat to the system. It moves heat from one location to the other, and that takes energy. In a closed system, like a sealed camera, that's bad! You will just make things hotter. In most devices that use them there is either a big heat sink on the outside of the unit, or a fan to blow air across the peltier device to get rid of the excess heat... I suppose you could use the bottom of the camera as the heat sink and then use a metal tripod to help conduct it away, but most of the time that isn't an option.... and as mentioned above, you would drain the battery very fast.

25
You can find these folks in Yellowstone standing within ten feet of bison with their 18-55's and iPads.
and inside grizzly and polar bears.....

26
Animal Kingdom / Re: A few wildlife images
« on: August 26, 2014, 11:26:30 AM »
Here's a few wildlife favs..
#2, the fox out mouse hunting.... That is absolutely perfect timing! Congratulations!

27
Animal Kingdom / Re: Your best animal shots!
« on: August 26, 2014, 11:25:18 AM »
Hi,

my name is Stefan and I am from germany.

I'd like to show you, 3 of my all-time-fav pics:


I REALLY! like the first one.....

28
I've been waiting for it for years but have given up hope that Canon actually listens to their user base  :(

you can only wonder how they manage to still sell the most DSLRs.....
it seems canon knows better what the majority of the silent userbase will.

im waiting too but the repeating of the above statement doesn´t make it true.

i bet canon has more inside information about what the users want than what is written on geek websites with a few thousand members at most.
Unfortunately, the masses seem to want a $300 crop camera left in automatic mode, with an 18-250 or 300 mm all-in-one zoom lens.....

29
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 26, 2014, 11:16:02 AM »
snip

You of course are correct. I was fixating on the number of possible entries, not the entries themselves. This is why we don't drink and post. Carry on.

Plus, as we approach a problem/question from different backgrounds, we see things differently.... It often helps when we try to explain ourselves and show examples. Many times we are saying the same thing with different words.... A pleasant and professional discussion helps everyone out.

30
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 26, 2014, 08:16:47 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

I think what 3kramd5 was getting at was that no system has zero noise. When we convert the voltage of a pixel into an ADU with the ADC, we cannot convert a fraction of an ADU. If RN is 3e- and FWC is 60ke-, then 3e- RN, although in floating point precision is 0.8192, ADUs are integer (at least, they are in todays sensors...maybe at some point we'll have cameras that can convert directly into 32-bit float RAW. :D) Since ADUs are integer, you cannot convert any non-zero charge to zero...the minimum ADU is 1, or 2^0.

DSP (Digital Signal Processing) 101......

A N bit D/A converter is capable of resolving 2^N states. A 4 bit D/A can resolve 16 states, an 8 bit D/A can resolve 256 states, and a 14 bit D/A can resolve 16,384 states. I think we can all agree on this.

So with a 14 bit D/A there are 16,384 states. These states are represented as binary 00 0000 0000 0000 to 11 1111 1111 1111, or 0 to 16,383 in decimal.

The signal that we wish to measure is typically fed through an amplifier (or attenuator for large signals) so that it's maximum value will be scaled to the input range of the A/D converter. For example, lets say we have an 8 bit D/A converter that works from 0-15VDC.... if we are using it to measure a signal from 0 to 1VDC then we only get the last 4 bits of resolution toggling and we have thrown away the accuracy of the system. Scale the input signal up by 15X and now you get all bits toggling. In this system the state 0000 0000 does not represent 0 volts, it represents from 0 volts to less than 15Volts/256 (0.0586 volts). Likewise, the state 1111 1111 does not represent 15 volts, it represents from 14.9414 volts to 15 volts. Each state represents a range, not an absolute value. The state 1111 1111 is special, it also represents the overload condition where an input signal is high enough to saturate the converter.

So back to our Canon 14 bit A/D....
It's lowest possible reading is 0, it's highest possible reading is 16,383. In any circuit there is the noise floor... the lowest level of signal found in the input signal. In a well designed circuit, the resolution of the A/D converter will be less that the noise floor. What this results in is the last few bits of the A/D converter toggling almost at random. The noise comes from our amplifier, from our converter, from fluctuations in our reference voltage on the A/D converter, and from outside. When we get rid of our least significant digits that are toggling randomly, we are left with the "significant digits".

My suspicion is that Canon does not use 14 bit A/D converters, but uses 16 bit or even 20 bit A/D and throws away all but the most significant 14 bits.

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