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Messages - x-vision

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61
EOS Bodies / Re: EOS 7D Mark II & Photokina
« on: August 29, 2014, 10:47:49 PM »
As I said. Technology has been marching on.

Right.

But even with light-guides (to guide the light onto the photodiode), there are still limits as to much you can shrink pixels.
These are physical entities and you cannot shrink them indefinitely with a given technology.
The light guide cannot have a diameter zero, which is obvious even from the picture you posted - if your keep shrinking the pixels.

You make it sound as if smaller pixels are always better - and that's not unconditionally true.
That's the only point that I'm making.

There's a physical limit that cannot be crossed.
That's why manufacturers are using finer and finer CMOS processes (Panasonic is down to 65nm now).
And also looking for alternative solutions - like BSI, Sony's stacked technology, etc..

So, smaller pixels are generally better - but only when newer, more advanced technologies are used.

There's also the issue of the full-well capacity of a photodiode.
Smaller full-well capacity automatically lowers SNR. You should know that.

So, it's a balancing act, really, for pixel engineers.
A blanket statement like 'smaller pixels are always better' is just that - a blanket statement.
Some necessary small print needs to be added to discussion 8).

62
EOS Bodies / Re: EOS 7D Mark II & Photokina
« on: August 29, 2014, 09:45:36 PM »
Assuming equivalent or better sensor technology, more pixels is never bad.

You mean assuming better technology only.
For equivalent technology, this works only up to a point - at least for front-illuminated sensors.

In a front-illuminated sensor, the photodiode of a pixel is located at the bottom of a well, basically (see the left diagram):



The well is formed by the layers of metal wiring above the photodiode.

As pixels shrink, this well becomes narrower and narrower.
At some point, the well becomes so narrow that the micro-lenses on top can no longer focus the light on the photodiode.
This leads to light losses - and the resulting image quality degradation.

Thus, to further shrink the pixels, you need to switch to a finer CMOS process (or maybe BSI).

The likely reason that the 5DIII has 'only' 22mp is not because Canon no longer believes in megapixels (they do).
Rather, Canon appears to have hit the shrinking limit of their 500nm CMOS process, on which the 5DIII sensor is made.

The 70D is likely made on a finer CMOS process (180nm?), though, as I can't imagine that they've
been able to stretch their 500nm process to make the 20mp/dual-pixel sensor of the 70D.

So, smaller pixels are indeed generally better.
It's not a free ride, though; there limits as to how much you can shrink with a given technology.
Beyond that, you need to change your technology - or image quality degrades with smaller pixels.


63
EOS Bodies / Re: EOS 7D Mark II & Photokina
« on: August 28, 2014, 12:06:38 PM »
I still say it's possible that it's the 70D sensor and new technology (better performance) at the same time.  This is because it's possible that DIGIC 6 will reduce read noise from the same sensor compared to DIGIC 5+ in the 70D.

The ISO range is reportedly the same as on the 70D, which doesn't bode well.
I really hope that I'm wrong, though :(.

64
EOS Bodies / Re: Are you planning to purchase a 7D2
« on: August 27, 2014, 12:35:36 PM »
As a 70D owner, I'm very interested in the 7DII, as I'm hoping for better image quality.
But if the 7DII has the 70D sensor, I won't be buying it (at least until it gets heavily discounted).

65
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 27, 2014, 12:31:00 PM »
Definitely an indication of pent-up demand..... I wonder how many will purchase one?

The 7D has had a unique value proposition of having advanced specs at an affordable price.
And now that a refresh is coming, there's naturally a lot of interest in its successor.

The thing is, many tried the original 7D but weren't impressed by its image quality.
The hope is that the 7DII will address that.

If the currently rumored specs are real, though, the 7DII will have the 70D sensor.
So, not much of an improvement in image quality.

Thus, the big interest in the 7DII might not translate into big sales.

Canon supposedly knows their business.
But they will be missing a golden opportunity, IMO, if they don't put a better sensor in the 7DII.
A certain group of users are reluctant to move to FF - and yet, wold appreciate better image quality.

As a 70D owner, I'm very interested in the 7DII. So, I'm (actively) contributing to the big interest in the 7DII.
I won't actually be buying one, though, if IQ is the same as the camera that I already have.

66
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 24, 2014, 07:49:46 PM »

Let me also add, I'm not saying Canon's cameras are terrible. In fact, they're quite capable of getting good results. It's just that Canon no longer seems to care about having the best image quality (at least sub $6k) and being on the cutting edge in terms of features and sensor, and to me it's disappointing, regardless of sales figures, that other companies can offer overall better sensors AND better cameras, at a cheaper price.

If you want to measure "better" by sales figures, go ahead but I'm just talking about my subjective views of "better."

My sentiments exactly!

67
EOS Bodies / Re: Update on the EOS 7D Mark II Spec List
« on: August 24, 2014, 01:57:00 PM »
Here are the numbers (scroll down to the second table):
http://www.chipworks.com/en/technical-competitive-analysis/resources/blog/full-frame-dslr-cameras-canon-stays-the-course/

Two years old... Srsly where do you people get that fact that they don´t use 180nm or even smaller tech for new sensors? I see no hint of this or opposite....

The 1DX, 5DIII, and 6D are all made on old 500nm CMOS process - whether you like it or not.

The only newer sensor than that is the 70D sensor.
There's no publicly available info on which process it is using.
It's possible that it's made on 180nm process, considering the dual-pixel tech.
This has not been confirmed, though.

On the other hand, even the 70D is using off-sensor A/D conversion - like all other Canon sensors.
This is visible with the naked eye if you look at the 70D main circuit board.
It also explains the typical low DR score on DxO.

When Canon announces a 4K/60fps video sensor (either in a DSLR or in a Cinema camera),
this will be a sure sigh that they have moved to on-sensor ADC and newer manufacturing process.
This is when Canon's DR scores will shoot up to match/exceed the competition.

Until then, Canon will continue lagging behind Sony and Nikon in DR.
Deal with it  8).

68
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 24, 2014, 03:47:30 AM »

It is the ONLY relevant number. The definition of DR is not up for debate.

How hard you can push shadows due to noise (i.e. grain) is LATITUDE.

Look, man, call it anything you want. Here's the deal, though:

FF cameras have less noise than crop cameras. No one argues about that.
With ... ahem ... LATITUDE, it's the exact same thing: you have less noise in the shadows.

But in both cases, it's all about having less noise.

And it's very silly to argue that with some extra noise reduction, things get equalized. No, they don't.
By the same token, you can clean up an image from a crop camera and proclaim that crop is better than FF.
Would anyone take you seriously if you do that?

So, why are you doing it for DR ??

Having more DR (what you call latitude) gives you images with cleaner shadows - just like a FF camera gives you cleaner images overall.
And having cleaner shadows/images is a clear advantage. Why are you downplaying it?
What you are doing is the same as downplaying the noise advantage of FF vs crop.

It seems to me that you just can't accept that Canon, your home team, is not winning in this particular instance.

69
EOS Bodies / Re: Update on the EOS 7D Mark II Spec List
« on: August 24, 2014, 02:17:41 AM »
Really, though - How'd you find yourself (jrista and whomever else) so informed about the sensor tech and fabrication processes of the different manufacturers?

Don and Jrista are right.
For their FF sensors in particular, Canon is still using an old manufacturing process.
See the link that I posted above.

70
EOS Bodies / Re: Update on the EOS 7D Mark II Spec List
« on: August 24, 2014, 02:02:33 AM »
Ha, cheers, Don! I'm feeling thoroughly educated now ;)
Really, though - How'd you find yourself (jrista and whomever else) so informed about the sensor tech and fabrication processes of the different manufacturers? I hear people mention it on these forums all the time but is it as simple as just being in spec sheets somewhere and coming to conclude that the numbers in Panasonic's data are smaller?...
Seriously though, Canon is using old tech for their APS-C and FF sensors. I don't have the numbers in front of me ...

Here are the numbers (scroll down to the second table):
http://www.chipworks.com/en/technical-competitive-analysis/resources/blog/full-frame-dslr-cameras-canon-stays-the-course/

71
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 23, 2014, 04:20:43 PM »
Are there really that many indie movie makers that are shooting in 4K nowadays or is this just all baloney?

4K is the future-proof format. That's why it's important even now, when 4K TVs are still not the norm.

72
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 23, 2014, 04:43:48 AM »
it´s still just guesswork.

... but based on years of experience  8).

No point to argue here, as it's really guesswork on my part.
But you will be disappointed if you expect better IQ than the 70D.
Like I said, trust me on that ;).

73
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 23, 2014, 04:38:09 AM »
In Canon's product hierarchy, FF ... has better image quality than crop.

Amazing how Canon's product hierarchy aligns so well with physics (or maybe the other way around?)...   ;)

Well, physics would have been 'challenged' at the transition period, when a smaller sensor has superior tech vs the larger - but old - sensor.

But Canon is not taking this risk.

74
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 23, 2014, 04:36:38 AM »
obvious?

how can you say that?
you know nothing about the new sensor, do you?

Well, the leaks that appear two weeks before announcement are usually 100% right.
So, these latest specs are the real thing - trust me on that ;).

And then if it looks like a duck, you know it will quack like a duck too.
You will see  - trust me on that ;).

75
EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 23, 2014, 04:16:48 AM »
OK, We can expect a 1700$ for this, no more!

And why the hell, they have wait 5 full years to produce just this upgrade?

Yup. But it's clear to me now that Canon just won't make a 1.6x camera that would challenge FF in term of image quality.

A 7DII with new sensor tech would have been too close to the 5DIII and 6D in image quality (or even better?).
I was hoping for just that - but it's obviously not happening.

In Canon's product hierarchy, FF is both more expensive and has better image quality than crop.
And this obviously remains unchanged for now.

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