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A future technology for dSLRs?

 
 
Wolfgang Weisselberg
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      11-22-2009
David J Taylor <(E-Mail Removed)-this-bit.nor-this-part.co.uk.invalid> wrote:

> .. and probably something which could be easily added to any sensor-shift
> camera at little cost, perhaps providing /some/ image quality improvement.


why not go the whole nine yards, use a monochrome sensor (no bayer
pattern at all) and a slew of filters? In that way you'd not
only have some broad filters which sort-of center on red, green
and blue --- you could use narrow spectrum filters in addition
and IR-pass and UV-pass filters and cyan, yellow, magenta and
emerald and filters for all the difficult to resolve colours, too.

Works perfectly well in our remote probes, in space, currently
on Mars, too --- even worked on the hot and inhospitable Venus.

It doesn't need a sensor shift mechanism but uses well known and
time-tested methods. It also offers much higher effective ISO
values for monochrome shots when used with a clear or missing
filter, as no Bayer filter reduces the passing light.

But if you insist on a sensor shift, make it shift sub-pixel
distances ... 16 (i.e. 4x4) images could quadruple the resolution.
The software to do so is already available, look e.g. here
http://auricle.dyndns.org/ALE/gallery-auto/

In addition, you can use it for many scientific tasks by just
choosing the correct set of filters.

> Whether there are many lenses that would justify the potential quadrupling
> of the resolution is another question.


You get close to quadrupling as often as you win the national
lottery. It *could* happen, theoretically ...
The average case would be about 30-50% more resolution.

Remember that the green filter is broad, and records also red
and blue light, just weaker.

-Wolfgang
 
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nospam
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      11-22-2009
In article <(E-Mail Removed)>, Alfred
Molon <(E-Mail Removed)> wrote:

> > since bayer cameras have as much as 5 times as many pixels (in the same
> > 35mm form factor), you can make substantially bigger enlargements than
> > with foveon. if you step up to medium format backs, it's over 12 times
> > as many pixels.

>
> What are you talking about? 5 times as many pixels compared to what?


all of sigma's current cameras (including the vaporware sd15) have the
same 4.7 megapixel sensor they introduced a few years ago. meanwhile,
nikon, canon and sony have sensors as high as 24 megapixels. dividing,
24 by 4.7 is 5.11 times as many pixels.

phase one has a 60 megapixel medium format back. 60/4.7 = 12.77 times
as many pixels.
 
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nospam
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      11-22-2009
In article <(E-Mail Removed)>, Alfred
Molon <(E-Mail Removed)> wrote:

> > of course it would be preferable *if* you could do it without
> > compromising anything else. unfortunately, there's no free lunch.
> >
> > the reality is you end up compromising on things which are far more
> > important than having higher colour resolution. you *will* see higher
> > noise and colour casts, but you won't see the added colour resolution
> > and a slow frame rate is not desirable for some types of photography,
> > such as sports.

>
> There is a free lunch and no compromising with this piezo actuator
> system, if the scene is static.


that's hardly a free lunch. it's only free if you aren't moving, which
rules out just about everything other than still life with the camera
on a tripod.

> In any case, with a Bayer system you throw away 2/3 of the light with
> the colour filters. It's just a matter of finding a way to use all
> incoming light, then there will be no performance degradation.


and that 2/3 is regenerated with excellent accuracy. that's why it's so
clever.
 
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Ray Fischer
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      11-22-2009
Wolfgang Weisselberg <(E-Mail Removed)> wrote:
>David J Taylor <(E-Mail Removed)-this-bit.nor-this-part.co.uk.invalid> wrote:
>
>> .. and probably something which could be easily added to any sensor-shift
>> camera at little cost, perhaps providing /some/ image quality improvement.

>
>why not go the whole nine yards, use a monochrome sensor (no bayer
>pattern at all) and a slew of filters?


Too slow.

--
Ray Fischer
http://www.velocityreviews.com/forums/(E-Mail Removed)

 
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nospam
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      11-22-2009
In article <(E-Mail Removed)>, Alfred
Molon <(E-Mail Removed)> wrote:

> > > Hasselblad are not quadrupling the resolution, they are just achieving
> > > the full nominal resulution of the sensor (as opposed to Bayer sensors,
> > > where the effective resulution is somewhere between ~ 30-100% of the
> > > pixel count, depending on the scene captured).

> >
> > completely wrong.

>
> True instead.


nope. it's completely wrong. bayer resolution is *not* dependent on the
scene in normal situations. in synthetic situations, such as a colour
res chart, it does degrade, but so does the human eye. not much point
in capturing what you can't see.
 
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Ray Fischer
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      11-22-2009
nospam <(E-Mail Removed)> wrote:
>In article <(E-Mail Removed)>, Alfred
>Molon <(E-Mail Removed)> wrote:
>
>> > > Hasselblad are not quadrupling the resolution, they are just achieving
>> > > the full nominal resulution of the sensor (as opposed to Bayer sensors,
>> > > where the effective resulution is somewhere between ~ 30-100% of the
>> > > pixel count, depending on the scene captured).
>> >
>> > completely wrong.

>>
>> True instead.

>
>nope. it's completely wrong. bayer resolution is *not* dependent on the
>scene in normal situations. in synthetic situations, such as a colour
>res chart, it does degrade, but so does the human eye.


When you insist that he's wrong and then proceed to describe how he is
right it makes you look like an argumentative asshole

--
Ray Fischer
(E-Mail Removed)

 
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Ray Fischer
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      11-22-2009
nospam <(E-Mail Removed)> wrote:
>In article <(E-Mail Removed)>, Alfred
>Molon <(E-Mail Removed)> wrote:
>
>> > of course it would be preferable *if* you could do it without
>> > compromising anything else. unfortunately, there's no free lunch.
>> >
>> > the reality is you end up compromising on things which are far more
>> > important than having higher colour resolution. you *will* see higher
>> > noise and colour casts, but you won't see the added colour resolution
>> > and a slow frame rate is not desirable for some types of photography,
>> > such as sports.

>>
>> There is a free lunch and no compromising with this piezo actuator
>> system, if the scene is static.

>
>that's hardly a free lunch. it's only free if you aren't moving, which
>rules out just about everything other than still life with the camera
>on a tripod.


One need only look at any catalog to see all of the many photos taken
of still objects.

>> In any case, with a Bayer system you throw away 2/3 of the light with
>> the colour filters. It's just a matter of finding a way to use all
>> incoming light, then there will be no performance degradation.

>
>and that 2/3 is regenerated with excellent accuracy.


But not as good as it could be.

--
Ray Fischer
(E-Mail Removed)

 
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nospam
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      11-22-2009
In article <4b09ca66$0$1666$(E-Mail Removed)>, Ray Fischer
<(E-Mail Removed)> wrote:

> >> There is a free lunch and no compromising with this piezo actuator
> >> system, if the scene is static.

> >
> >that's hardly a free lunch. it's only free if you aren't moving, which
> >rules out just about everything other than still life with the camera
> >on a tripod.

>
> One need only look at any catalog to see all of the many photos taken
> of still objects.


there are many more photos of moving objects, namely people, who often
are holding the objects in the catalogues you mention.

> >> In any case, with a Bayer system you throw away 2/3 of the light with
> >> the colour filters. It's just a matter of finding a way to use all
> >> incoming light, then there will be no performance degradation.

> >
> >and that 2/3 is regenerated with excellent accuracy.

>
> But not as good as it could be.


with today's technology it is.
 
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nospam
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      11-22-2009
In article <4b09ca19$0$1666$(E-Mail Removed)>, Ray Fischer
<(E-Mail Removed)> wrote:

> >nope. it's completely wrong. bayer resolution is *not* dependent on the
> >scene in normal situations. in synthetic situations, such as a colour
> >res chart, it does degrade, but so does the human eye.

>
> When you insist that he's wrong and then proceed to describe how he is
> right it makes you look like an argumentative asshole


read it again. it's *only* an issue with artificial scenes that don't
occur in the real world. it's *not* a problem in normal usage,
especially since the eye can't see the difference.

nothing is perfect and *any* camera is going to have an edge case where
it falls apart.
 
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Wolfgang Weisselberg
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      11-23-2009
Alfred Molon <(E-Mail Removed)> wrote:

> In any case, with a Bayer system you throw away 2/3 of the light with
> the colour filters.


How do you calculate 2/3rds? Have you counter-checked that with
absorbtion curves from real filters used for that purpose?

And how does that stop and a bit compare to the approximately
two stops you throw away by using a front-lit sensor? And what
about the light loss in the optics --- every glass-glass and
every glass-air surface costs light!

And finally, when you need every photon, how comes that Foveon
suffers so badly in high ISO settings compared to Bayer pattern
sensors?

-Wolfgang
 
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