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03-06-2016, 01:25 PM   #766
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QuoteOriginally posted by falconeye Quote
Wrt the discussion started by @Simen1 ...

His arguments are all sound and valid.

Speaking generally however, there is, for any given image quality and any given moment in time, a sweet spot (for sensor size) which delivers this image quality in the most cost-effective way (read, at the lowest possible price).

I tried to elaborate a bit about this topic in my blog.

Two things to observe:
  1. The sweet spot wanders towards larger sensor sizes over time.
  2. The sweet spot wanders towards larger sensor sizes when increasing the given image quality.
The reason for #2 is that beyond some point, the cost of implementing the lens grows much faster than the cost of implementing the sensor. Think of the cost of f/0.5 lenses ...

The reason for #1 is that cost of silicon decreases over time, while the cost of glass does decrease less rapidly or does even increase.

To make things worse, #1 and #2 combine to yield a cummulative effect to favor larger sensor sizes over time, more rapidly than some people believe.

This is a general fact which can't be denied as it can be proven rigorously.

There are a few intersting corrolars to the above:
  • Pentax would vanish in the enthusiast market if they don't upgrade to FF at some moment in time (one may still argue about the correct moment in time though -- for many it is just right now, for some, too early, for some including myself, it is about 4 years too late).
  • FourThirds will be adopted by smaller image quality standards (such as compacts) and will become extinct in the enthusiast market.
  • Because small lenses (and small cameras) are a most-wanted item, there will be such lenses for, e.g., full frame, in the future. Just like professional-grade F/4 primes and F/5.6 zooms. This is still a large gap in the market and IMHO, one of a few ways Pentax could differentiate and gain market share. That's also one of the strengths of the Leica line-up.
  • As the difference between FF and cropped 44x33 medium format is so little (0.8x crop factor), all current medium format vendors will have to provide an upgrade path to full medium format, at an affordable price. Except maybe Leica, which replaces Leica S by Leica SL.
  • A fixed lens 44x33 medium format mirrorless camera must be imminent. The question is who delivers it first ...
  • There is an option ... that Canon and/or Nikon, when eventually jumping to professional-grade mirrorless, do this with cropped 44x33 medium format. As it would be affordable enough, saves their DSLR business from cannibalism, allows them to introduce a new mount with no questions asked, and bridges AF performance until multi-pixel AF has achieved professional tracking performance (which it eventually will -- btw, Sony just delivered a Dual-Pixel AF sensor to Samsung ...).
  • ... many more corrolars exist, think about it for a few minutes ...
I agree 100% with your analysis.

03-06-2016, 01:54 PM   #767
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The problem that I have with equivalence (which is what we are talking about in veiled terms here) is that it tends to emphasize wide open performance to the exclusion of everything else. If you happen to be someone who shoots at f2.8 or f4 on APS-C most of the time and doesn't really want to shoot f1.4 on full frame, much less the same thing on medium format, then it doesn't really matter if you can get a 35mm f1 lens or not.

On the other hand, if the value of a system comes down to which one has the fastest lenses available, then Leica probably wins hands down.

I would just say that when I look at medium format photos, I see a couple of things that stand out. They have really nice transitions from in focus to out of focus and they have an awful lot of detail without looking over processed. Now, some of that is attributable to the excellent skills of those who purchase Medium Format cameras, some is attributable to the excellent glass (few of these images if any are shot at f4 or wider), and some is attributable to the quality of the sensors. I have a hard time sorting how much is how much, but I would say that those who purchase medium format know what they are getting into and tend to have good skills prior to getting such a camera and they get it more for the glass than for the sensors, even though those are excellent.
03-06-2016, 01:56 PM   #768
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QuoteOriginally posted by thibs Quote
Ever looked through a 645Z VF? No? Then you can't understand (this is serious and not trying to insult you or something). Do it but you'll cry looking in any other VF then
No, I haven’t, but I have been looking trough the VF of a Pentax 6x7, a Bronica 6x7, a Hasselblad D3..something and a few more film based medium format cameras. Its quite a view! Just for the curiosity of it, I also tried a few large format cameras 4x5, 8x10 inch and a gigantic camera where I sat in a sofa inside the camera. Picture here.
03-06-2016, 03:38 PM - 1 Like   #769
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QuoteOriginally posted by biz-engineer Quote
As far as cost / image quality, I think Falc is right. But he does not comment about the size and weight of the glass to put in front of a larger sensor.
A statement about that was implied in my post.
Because size and weight of the glass to put in front of a sensor is (as a first order approximation) independend of the sensor size (assuming a given image quality), I focussed on the cost of said glass. And that's decreasing with increasing sensor size.

QuoteOriginally posted by Nicolas06 Quote
Outside of a few areas (graphics, scientific computations) general purpose program don't gain much with this approach.
...
So I stand my point. We stagnate.
Even though this doesn't effect my argument, I disagree.

I agree that Moore's law does no longer apply. Point taken.

But Moore's law never was a law, it was a stupid extrapolation from observation. Unlike the laws of physics.

As long as no law of physics needs be broken though (which has never been possible and never will be), there is no direct limit for technological progress and no reason either why it should happen in a linear (or exponential) fashion.

And there fortunately is no law of physics which sets a lower limit for the space-time volume or energy required to do a computation. Even quantum physics sets no such barrier.

Which btw is unlike photography because physics does indeed set a hard barrier how the best possible camera (in a given space-time volume) can perform.

So, there will be progress in computational hardware. But nobody said it will be easy. Maybe, some new materials need be researched, maybe, it is sufficient to further miniaturize volume and power consumption of the current technology.

IMHO, drastically reducing power consumption alone will do the trick. Because wrt all other parameters, we already beat the humain brain made from organic materials. But we are still way below its processing power (*) resulting from its 0.15 quadrillion synapses [http://postcog.ucd.ie/files/Pakkenberg%202003.pdf] (~300 Petaflops). CMOS has the same processing density but it would simply melt down if scaled to the capacity of our brain (which is no lightweight construction either, with its separate circuitry for cooling and fuel) ...

Once that problem is solved though, we can leave all other problems to them (i.e., those artificial brains). No way the progress could stop there

___
(*) The current #1 supercomputer (33 Petaflops or 1/10 the speed of a single human brain) consumes 18 MW or what 1 million brains consume, leaving a gap of 1:10,000,000 wrt energy efficiency ...


Last edited by falconeye; 03-06-2016 at 03:56 PM.
03-06-2016, 04:01 PM   #770
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QuoteOriginally posted by falconeye Quote
A fixed lens 44x33 medium format mirrorless camera must be imminent. The question is who delivers it first ...
There is an option ... that Canon and/or Nikon, when eventually jumping to professional-grade mirrorless, do this with cropped 44x33 medium format. As it would be affordable enough, saves their DSLR business from cannibalism, allows them to introduce a new mount with no questions asked, and bridges AF performance until multi-pixel AF has achieved professional tracking performance (which it eventually will -- btw, Sony just delivered a Dual-Pixel AF sensor to Samsung ...).
Two very good points. A couple of years ago I thought Samsung was going to mass produce MF mirrorless cameras, with or without a mount. Now it could be many others, maybe even Pentax.

QuoteOriginally posted by Nicolas06 Quote
Only partially. People don't buy MF for high iso, they don't even buy necessarily for more MP and they don't buy neither for the max apperture / shallow deph of field.
So, they are buying MF because of they have the money and like large viewfinders? I just feel more sure that Pentax will release a full frame medium format camera soon, probably with the same 100Mp sensor as Phase One.

QuoteOriginally posted by Rondec Quote
The problem that I have with equivalence (which is what we are talking about in veiled terms here) is that it tends to emphasize wide open performance to the exclusion of everything else. If you happen to be someone who shoots at f2.8 or f4 on APS-C most of the time and doesn't really want to shoot f1.4 on full frame, much less the same thing on medium format, then it doesn't really matter if you can get a 35mm f1 lens or not.
I'm sorry If I contributed to that impression. I use the equivalency term more widely. I.E. when carefully trying to get the same large enough DoF at the same distance and field of view on different formats. When I claimed two stops larger apertures available for FF then MF, it was meant in the context "even at the ends of the aperture and ISO scales, this holds true".
03-06-2016, 04:01 PM   #771
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--- please delete duplicate ---

Last edited by Simen1; 03-06-2016 at 04:30 PM.
03-06-2016, 04:15 PM   #772
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Speaking of lens weight, size and cost, its been a public fact that sensors should always be larger then the image circle of the indented optics, and not the other way around. But a few m43 cameras and a Nokia phone did come with a slightly larger sensor then image circle. They called it multi aspect sensor and crop away the corners. I think thats a great idea because they effectively increases the sensor without increasing the size, weight and cost of the lens. A larger portion of the image circle is used. The mentioned products don’t offer a full readout of all the pixels, but if they did, you could choose aspect ratio in post processing. With ASP-C lenses on K-1 you effectively have a multi aspect sensor with more freedom to choose. You could even make almost circular 180 degrees fisheye images with a fisheye lens made for rectangular APS-C with 180 degree diagonal. Quadratic images could use a lot more of the APS-C image circle area, compared to using a APS-C camera. Most lenses have a variable image circle. In some cases a FF lens might actually cover a 33x44mm MF sensor.

What I'm trying to say here is that I can easily see the sensors grow more then the image circles, because the latter drives size and weight more then the former. If lets say a 33x44mm sensor gets cheap enough It can replace a FF sensor even without changing the mount. A K mount camera with a 33x44mm multi aspect sensor could actually have meaningful advantages over FF, worth paying extra for. Likewise, having a FF camera with only APS-C lenses can prove to give meaningful advantages over having a APS-C camera with the exact same APS-C lenses.

Last edited by Simen1; 03-06-2016 at 04:54 PM.
03-06-2016, 04:41 PM   #773
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QuoteOriginally posted by falconeye Quote
...
And there fortunately is no law of physics which sets a lower limit for the space-time volume or energy required to do a computation. Even quantum physics sets no such barrier.
...
Not that it matters at all for the discussion or cameras at the moment, but doesn't thermodynamics and entropy laws set those limits? =) (Like the ones mentioned in https://en.wikipedia.org/wiki/Limits_to_computation)

03-06-2016, 07:06 PM   #774
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QuoteOriginally posted by Igor123 Quote
Not that it matters at all for the discussion or cameras at the moment, but doesn't thermodynamics and entropy laws set those limits? =) (Like the ones mentioned in https://en.wikipedia.org/wiki/Limits_to_computation)
There of course are limits at a finite temperature.
And there also is a lower limit for energy required per computation per second.
The black hole limits are pseudo-science as no theory for quantum gravity is established. None of which is in contradiction with my previous statement.
03-06-2016, 11:12 PM   #775
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QuoteOriginally posted by Simen1 Quote
They called it multi aspect sensor and crop away the corners.
Yep and Panasonic does just that on their LX serie. Quite nice IMO: whatever aspect (4:3, 3:2, 16:9) you get almost same pixel amount.

---------- Post added 07-03-16 at 07:16 ----------

QuoteOriginally posted by falconeye Quote
I agree that Moore's law does no longer apply. Point taken.

But Moore's law never was a law, it was a stupid extrapolation from observation. Unlike the laws of physics.
...
I'm often desperate reading the other way around. Thank you.
03-07-2016, 12:56 AM   #776
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QuoteOriginally posted by thibs Quote
Yep and Panasonic does just that on their LX serie. Quite nice IMO: whatever aspect (4:3, 3:2, 16:9) you get almost same pixel amount.
On average, it is not as good as if they had put an m4/3 capable lens and you cropped when creativity call for another aspect ratio. Worse, if you don't get the aspect ratio right at shooting time, then you are penalized 2 time. You start from 12MP only that you need to crop.

The only true benefit for me is that it allowed to keep the optics lighter/smaller. Look like you get an f/2.8-4 18-50 APSC equivalent
03-07-2016, 01:11 AM   #777
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QuoteOriginally posted by Simen1 Quote
I'm sorry If I contributed to that impression. I use the equivalency term more widely. I.E. when carefully trying to get the same large enough DoF at the same distance and field of view on different formats. When I claimed two stops larger apertures available for FF then MF, it was meant in the context "even at the ends of the aperture and ISO scales, this holds true".
But reality is a bit different. Only at the end of appertures and ISO scale does it truely matter.

Noise levels of APSC, m4/3 or APSC are so good at low iso that it doesn't matter. When I take a landscape at f/8 iso 100 with DA15 or a portrait at f/2.8 iso 100 with FA77 I don't feel like I would absolutely need an FF or MF body for the terrible noise I get.

I understand I could get less noise on FF with a 22mm at f/11 or 115mm at f/4, but this doesn't really matter because the picture I good enough to be printed quite large.

You'd need go past 30x40" to really see an issue and only looking from near distance.

It does only matter if I need to shoot past iso800 on APSC or if I need an apperture larger than my FA77 can handle (f/1.8). And even I'd find a 85mm f/1.4 if I wanted so...

Biggest gain for me with FF is the constant f/2.8 zoom behemoh that give lot of deph control, great AF capabilities and light gathering all with the conveniance of zoom. At the expense of price, weight and size.
03-07-2016, 01:23 AM   #778
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Nicolas06: If they did put a m43 capable lens in the LX100, it would work against its mission on being small and light. And If they did, they could have upgraded it to a APS-C sensor also, to bring back the multi aspect functionality.

The only thing I don’t like about multi aspect sensors is that current implementations takes away the freedom to choose aspect ratio in the post process (without unnecessary cropping)
03-07-2016, 03:25 AM   #779
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QuoteOriginally posted by falconeye Quote
Because size and weight of the glass to put in front of a sensor is (as a first order approximation) independend of the sensor size
yes, if glass is independent of sensor size => larger sensor with the lens equivalent of the one use on the smaller sensor => that mean longer and slower lens on FF. Ok , I see.

Last edited by biz-engineer; 03-07-2016 at 03:59 AM.
03-07-2016, 03:55 AM   #780
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QuoteOriginally posted by falconeye Quote
There of course are limits at a finite temperature.
And there also is a lower limit for energy required per computation per second.
The black hole limits are pseudo-science as no theory for quantum gravity is established. None of which is in contradiction with my previous statement.
Don't use that word. Psuedo science. It is theoretical physics

Last edited by D1N0; 03-07-2016 at 04:34 AM.
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