Fuji's DSLR killer

[A complimentary Cc of this posting was sent to
Alfred Molon
<alfred_molon.DeleteThis@yahoo.com>], who wrote in article <MPG.22072e8216876d0798b92b.DeleteThis@news.supernews.com>:
> In article <fnivuv$2egb$1@agate.berkeley.edu>, Ilya Zakharevich says...
>
> > There are other ways than phase-detection. TODAY these other ways are
> > not as convenient as phase-detection. But now, with live view, there
> > is a MAJOR incentive to investigate these alternative ways; when it
> > succeeds, dSLRs are dead.
>
> Other ways as good as phase detection? Can you make some examples?

Hmm??? Do you want me make some examples of the ways which are not
yet implemented, or what? As I said, TODAY the phase-detection is the
best of widely used TTL focussing methods.

[Without TTL, you might be able to use, e.g., laser distance meters
together with a well-calibrated lens capable of reporting the
position of its focussing ring.]

In Sci-Fi department: essentially, what phase-detection is doing is
parallax metering, using the parallax between the left and right
halves of entry pupil. In principle, one could do the same with the
existing life-view sensor, but putting a suitable microlens array in
front of the sensor. It would decrease the horizontal resolution
2x, and will duplicate the image, so the sensels mean

Rl Gl Rr Gr
Gl Bl Gr Bl

with Xl/Xr meaning X-color using the left/right halves of the lens.

[There may be "some" problems with alignment of the microlenses...]

But all this is a speculation...

Hope this helps,
Ilya
 >> Stay informed about: Fuji's DSLR killer 

dj_nme <dj_nme.TakeThisOut@iinet.net.au> wrote:

> If the resolution of an EVF was good enough to not require focus
> magnification, then it should be considered a true and viable
> alternative to an optical TTL viewfinder.
> Not before.

What about all those optical TTL viewfinders which needed the special
assistance of split images etc. for focussing?

--
Chris Malcolm cam.TakeThisOut@infirmatics.ed.ac.uk DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]
 >> Stay informed about: Fuji's DSLR killer 

Alfred Molon wrote:
> In article <fnivuv$2egb$1@agate.berkeley.edu>, Ilya Zakharevich says...
>
>
>>There are other ways than phase-detection. TODAY these other ways are
>>not as convenient as phase-detection. But now, with live view, there
>>is a MAJOR incentive to investigate these alternative ways; when it
>>succeeds, dSLRs are dead.
>
>
> Other ways as good as phase detection? Can you make some examples?

There are various other focusing mechanisms, but I'm not sure that they
could really be considered "better" than phase detection.
* Manual rangefinder focusing (as in Leica M, Konica Hexar, Contax I &
II, Zorki 4 & 4K and so on), but this requires an optical viewfinder,
mirrors/prisms for the rangefinder and masking (or accessory
viewfinders) to show focal length views in the viewfinder other than the
"standard" lens the designers chose.
* UltraSonic RF, the most famous brand to use this was Polaroid (on
their instant cameras), but ISTR that it's fooled into focusing on the
glass if shooting through a window.
* IR rangefinder focusing (quite a few AF P&S film cameras used this
method) and is quite fast. There must be some reason that it isn't used
on P&S digicams, perhaps it isn't accurate enough or only suitable for
close objects?
All of the above suffer from parralax at close distances, simply because
they aren't TTL focus methods, with US and IR you can't tell what you
they're focused on (only they've focused on "something") and are also
limited in accuracy so there is a only so long a focal length lens which
can be used (eg: Leica RF is limited to about 130mm FL as a maximum for
acceptable RF accuracy).

You could use Laser rangefinding, but perhaps there is eye safety to
worry about: you really don't want to blind your photographic subjects
or passers-by.

It might be possible to have phase detection mirrors which are in front
of the imaging sensor (they only take up a fraction of the image and
could use translucent mirrors to not degrade the live-view too much) and
have these little mirrors flip out of the way when a picture is taken.
The only problem I can forsee is that it would only be possible to put
sensors to detect focus around the edge of the image, otherwise you'd
have to put up with a focus mirror which is as large as the relfex
mirror in a SLR and has to flip out of the way for taking a picture just
the same.
 >> Stay informed about: Fuji's DSLR killer 

[A complimentary Cc of this posting was NOT [per weedlist] sent to
dj_nme
<dj_nme.DeleteThis@iinet.net.au>], who wrote in article <479d38c6$0$9764$5a62ac22@per-qv1-newsreader-01.iinet.net.au>:
> All of the above suffer from parralax at close distances, simply because
> they aren't TTL focus methods, with US and IR you can't tell what you
> they're focused on (only they've focused on "something") and are also
> limited in accuracy so there is a only so long a focal length lens which
> can be used (eg: Leica RF is limited to about 130mm FL as a maximum for
> acceptable RF accuracy).

With film cameras, parallax is not avoidable. With live-view, and
optical distance-meter, you/the-camera can see the point of focusing,
and tilt the distance-meter accordingly.

> You could use Laser rangefinding, but perhaps there is eye safety to
> worry about: you really don't want to blind your photographic subjects
> or passers-by.

IR is not very blinding...

> It might be possible to have phase detection mirrors which are in front
> of the imaging sensor (they only take up a fraction of the image and
> could use translucent mirrors to not degrade the live-view too much) and
> have these little mirrors flip out of the way when a picture is taken.
> The only problem I can forsee is that it would only be possible to put
> sensors to detect focus around the edge of the image, otherwise you'd
> have to put up with a focus mirror which is as large as the relfex
> mirror in a SLR and has to flip out of the way for taking a picture just
> the same.

Nope. The secondary mirror is really tiny, so its replacement does
not need to be larger. Moreover, the major problem with primary
mirror - that it needs to cover the focussing glass - is not present
with secondary one. Therefore, no "mirror flap noise", and WAYS
smaller vibration.

Yours,
Ilya
 >> Stay informed about: Fuji's DSLR killer 

In article <fnk3u1$2rcj$1@agate.berkeley.edu>, Ilya Zakharevich
<nospam-abuse RemoveThis @ilyaz.org> wrote:

> With film cameras, parallax is not avoidable. With live-view, and
> optical distance-meter, you/the-camera can see the point of focusing,
> and tilt the distance-meter accordingly.

With all of my film SLRs, what I see is what I get...no parallax.
 >> Stay informed about: Fuji's DSLR killer 

Ilya Zakharevich wrote:
> [A complimentary Cc of this posting was NOT [per weedlist] sent to
> dj_nme
> <dj_nme.RemoveThis@iinet.net.au>], who wrote in article <479d38c6$0$9764$5a62ac22@per-qv1-newsreader-01.iinet.net.au>:
>
>>All of the above suffer from parralax at close distances, simply because
>>they aren't TTL focus methods, with US and IR you can't tell what you
>>they're focused on (only they've focused on "something") and are also
>>limited in accuracy so there is a only so long a focal length lens which
>>can be used (eg: Leica RF is limited to about 130mm FL as a maximum for
>>acceptable RF accuracy).
>
>
> With film cameras, parallax is not avoidable. With live-view, and
> optical distance-meter, you/the-camera can see the point of focusing,
> and tilt the distance-meter accordingly.

You've missed the point, anything other than contrast detection focusing
currently requires either secondary mirrors or a seperate RF mechanism.
There is no avoiding it.

>>You could use Laser rangefinding, but perhaps there is eye safety to
>>worry about: you really don't want to blind your photographic subjects
>>or passers-by.
>
>
> IR is not very blinding...

That an emoticon is of you with one eye burnt out fom an IR laser, isn't it?
What you can't see can still damage your eyes, that is why commercial
laser pointers and laser sights (visibel and IR) are limited to below
5mW in power.

>>It might be possible to have phase detection mirrors which are in front
>>of the imaging sensor (they only take up a fraction of the image and
>>could use translucent mirrors to not degrade the live-view too much) and
>>have these little mirrors flip out of the way when a picture is taken.
>>The only problem I can forsee is that it would only be possible to put
>>sensors to detect focus around the edge of the image, otherwise you'd
>>have to put up with a focus mirror which is as large as the relfex
>>mirror in a SLR and has to flip out of the way for taking a picture just
>>the same.
>
>
> Nope. The secondary mirror is really tiny, so its replacement does
> not need to be larger. Moreover, the major problem with primary
> mirror - that it needs to cover the focussing glass - is not present
> with secondary one. Therefore, no "mirror flap noise", and WAYS
> smaller vibration.
>
> Yours,
> Ilya

Again you missed the point.
To have phase detection sensors for the centre of the image, you will
need a mirror which covers the centre of the imaging sensor to direct
that part of the image into the phase detection sensors and that
couldn't be any smaller than a reflex mirror for a DSLR (because it's
doing the same job, except to a phase detection sensor rather than to a
viewfinder) and would have to flip out of the way when a picture is
taken just the same as a reflex mirror in SLR camera would.
Or, you could have a pelical mirror (look up the Canon Pelix or EOS RT)
for your phase detection sensors and put up with losing at least 1 stop
of brightness at the imaging sensor.
I don't see the point of going to all this complexity and not having an
optical TTL viewfinder.
 >> Stay informed about: Fuji's DSLR killer 

[A complimentary Cc of this posting was NOT [per weedlist] sent to
dj_nme
<dj_nme RemoveThis @iinet.net.au>], who wrote in article <479dc5b7$0$10796$5a62ac22@per-qv1-newsreader-01.iinet.net.au>:
> > With film cameras, parallax is not avoidable. With live-view, and
> > optical distance-meter, you/the-camera can see the point of focusing,
> > and tilt the distance-meter accordingly.

> You've missed the point, anything other than contrast detection focusing
> currently requires either secondary mirrors or a seperate RF mechanism.
> There is no avoiding it.

You've missed the point. What I'm discussing is PARALLAX. With
live-view, auxiliary distance-meter can operate with no parallax -
meaning it can measure distance to the "marked point" in viewfinder.

> > IR is not very blinding...
>
> That an emoticon is of you with one eye burnt out fom an IR laser, isn't it?
> What you can't see can still damage your eyes, that is why commercial
> laser pointers and laser sights (visibel and IR) are limited to below
> 5mW in power.

I'm puzzled; why do you think anything more than 1/10th of this is
needed? 0.5mW is a mighty beam (for focussing purposes)...

> > Nope. The secondary mirror is really tiny, so its replacement does
> > not need to be larger. Moreover, the major problem with primary
> > mirror - that it needs to cover the focussing glass - is not present
> > with secondary one. Therefore, no "mirror flap noise", and WAYS
^^^^
slap
> > smaller vibration.

> Again you missed the point.

Same works for you again...

> To have phase detection sensors for the centre of the image, you will
> need a mirror which covers the centre of the imaging sensor to direct
> that part of the image into the phase detection sensors and that
> couldn't be any smaller than a reflex mirror for a DSLR (because it's
> doing the same job, except to a phase detection sensor rather than to a
> viewfinder)

Did you ever see the mechanics of a mirror? The focussing mirror IS
much much smaller than the main one. It is NOT doing the same job.

Reflecting away the center 30% of the image is NOT the same as
reflecting away 99% of the image; so the secondary mirror may be about
2x smaller. Moreover, the secondary mirror does not need to cover the
focusing screen, which is yet another restriction on the size of the
primary mirror.

> Or, you could have a pelical mirror (look up the Canon Pelix or EOS RT)
> for your phase detection sensors and put up with losing at least 1 stop
> of brightness at the imaging sensor.

There is no hard limit on transparency of a pelican. So it may be 1
stop, or 0.1 stop lost. The minimal eV would depend on the design of
the focussing system; with better design, you can have better
transparency with the same minimal-eV-of-focussing.

> I don't see the point of going to all this complexity and not having an
> optical TTL viewfinder.

LOL! Of course, if you forget about inferior optic, no way to take
movies, no tilt-screen focussing, no convenient low-light view,
weight, cost, the vibration-blur, (etc?) then there may be no point
indeed...

Yours,
Ilya
 >> Stay informed about: Fuji's DSLR killer 

Chris Malcolm wrote:

> dj_nme <dj_nme.RemoveThis@iinet.net.au> wrote:
>
>
>>If the resolution of an EVF was good enough to not require focus
>>magnification, then it should be considered a true and viable
>>alternative to an optical TTL viewfinder.
>>Not before.
>
>
> What about all those optical TTL viewfinders which needed the special
> assistance of split images etc. for focussing?

They don't really _require_ focus aides, they just make it easier to
manually focus.
It's not very hard to manually focus (for example) a Pentax K10D, you
can actually see were/when it is in focus on the matte focusng screen
supplied as origianl equipment.
 >> Stay informed about: Fuji's DSLR killer 

dj_nme <dj_nme.RemoveThis@iinet.net.au> wrote:
> Chris Malcolm wrote:

>> dj_nme <dj_nme.RemoveThis@iinet.net.au> wrote:
>>
>>
>>>If the resolution of an EVF was good enough to not require focus
>>>magnification, then it should be considered a true and viable
>>>alternative to an optical TTL viewfinder.
>>>Not before.
>>
>>
>> What about all those optical TTL viewfinders which needed the special
>> assistance of split images etc. for focussing?

> They don't really _require_ focus aides, they just make it easier to
> manually focus.
> It's not very hard to manually focus (for example) a Pentax K10D, you
> can actually see were/when it is in focus on the matte focusng screen
> supplied as origianl equipment.

What was the effective resolution of the matte screen?

--
Chris Malcolm cam.RemoveThis@infirmatics.ed.ac.uk DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]
 >> Stay informed about: Fuji's DSLR killer 

"Chris Malcolm" <cam DeleteThis @holyrood.ed.ac.uk> wrote:
> dj_nme <dj_nme DeleteThis @iinet.net.au> wrote:
>> Chris Malcolm wrote:

>> They don't really _require_ focus aides, they just make it easier to
>> manually focus.
>> It's not very hard to manually focus (for example) a Pentax K10D, you
>> can actually see were/when it is in focus on the matte focusng screen
>> supplied as origianl equipment.
>
> What was the effective resolution of the matte screen?

FWIW, I A/B compared my F707 EVF with the Canon 300D screen. Looking at the
same scene, the 300D completely blows the F707 away in terms of detail
that's clearly visible. And the F707 was one of the better EVFs. My estimate
is that the F707 would need at least 4 if not 9 times the pixels to compete.

And, of course, the 5D (which is no better than any generic 35mm SLR of the
OM-1n class) is significantly better than the 300D.

As has been pointed out, though, digital EVF camera can play magnification
games, so they don't need to complete in overall resolution, and are nowhere
as bad as the above comparisons imply. But...

For manual focus, the F707's magnification feature wasn't all that great.
For starters, the camera operates in "permanent DOF preview mode", that is,
the aperture is always stopped down to the taking f stop (it opens
automatically for in-camera AF and then stops down again), so you have to do
manual stop-down games in aperture priority mode to allow you to manually
focus with the lens wide open. Making manual focus almost useless.

I'd hope that other EVF P&S cameras aren't so dumb.

David J. Littleboy
Tokyo, Japan
 >> Stay informed about: Fuji's DSLR killer 

On Jan 24, 7:05 pm, Alfred Molon <alfred_mo....DeleteThis@yahoo.com> wrote:
> http://www.dpreview.com/news/0801/08012410fujifS100FS.asp
>
> 2/3" sensor, 11MP, IS, 28-400mm zoom, compact and lightweight
> --
>
> Alfred Molon
> ------------------------------
> Olympus 50X0, 8080, E3X0, E4X0, E5X0 and E3 forum athttp://tech.groups.yahoo.com/group/MyOlympus/http://myolympus.org/photo sharing site

Getting back on topic... one of the most interesting things I spotted
is that this camera is using real *optical* image stabilisation, via
floating lens element/s instead of a moving sensor. Theoretically
that may give it a slight advantage, but we all know how theories
sometimes turn out in practice...

As to the potential of the sensor, Fuji have in the past offered a
surprise or two - it would be nice to dream that the sensor will be
the sort of jump in technology that the F10 was in its day.

If they can get those areas working well, that pretty much just leaves
the EVF... when are bridge camera makers going to listen to all the
suggestions to supply a high-res EVF? I'd happily sacrifice a little
weight and bulk for a better viewfinder, even if monochrome...!
 >> Stay informed about: Fuji's DSLR killer 

Ilya Zakharevich wrote:
> [A complimentary Cc of this posting was NOT [per weedlist] sent to
> dj_nme
> <dj_nme DeleteThis @iinet.net.au>], who wrote in article <479dc5b7$0$10796$5a62ac22@per-qv1-newsreader-01.iinet.net.au>:
>
>>>With film cameras, parallax is not avoidable. With live-view, and
>>>optical distance-meter, you/the-camera can see the point of focusing,
>>>and tilt the distance-meter accordingly.
>
>
>>You've missed the point, anything other than contrast detection focusing
>>currently requires either secondary mirrors or a seperate RF mechanism.
>>There is no avoiding it.
>
>
> You've missed the point. What I'm discussing is PARALLAX. With
> live-view, auxiliary distance-meter can operate with no parallax -
> meaning it can measure distance to the "marked point" in viewfinder.

You don't seem to understand what causes parallax.
It is (with cameras) described the distance between a non-TTL viewfinder
and the imaging lens, causing a difference between what's seen in the
viewfinder and caputured on film/sensor.
In the case of external (non-TTL) rangefinders/focusing mechanisms, it
is the distance from the focus sensor to the imaging lens which will
cause parallax.
The amount of parallax is dependent on the distance to the subject: the
closer it is the more parallax is evident.
So you cannot just "put a mark in the viewfinder" as you so quaintly
insist, it won't remove the difference between what the RF is pointed at
and what the imaging lens is pointed at, especially at close ranges.

>>>IR is not very blinding...
>>
>>That an emoticon is of you with one eye burnt out fom an IR laser, isn't it?
>>What you can't see can still damage your eyes, that is why commercial
>>laser pointers and laser sights (visibel and IR) are limited to below
>>5mW in power.
>
>
> I'm puzzled; why do you think anything more than 1/10th of this is
> needed? 0.5mW is a mighty beam (for focussing purposes)...
>
>
>>>Nope. The secondary mirror is really tiny, so its replacement does
>>>not need to be larger. Moreover, the major problem with primary
>>>mirror - that it needs to cover the focussing glass - is not present
>>>with secondary one. Therefore, no "mirror flap noise", and WAYS
>
> ^^^^
> slap
>
>>>smaller vibration.
>
>
>>Again you missed the point.
>
>
> Same works for you again...
>
>
>>To have phase detection sensors for the centre of the image, you will
>>need a mirror which covers the centre of the imaging sensor to direct
>>that part of the image into the phase detection sensors and that
>>couldn't be any smaller than a reflex mirror for a DSLR (because it's
>>doing the same job, except to a phase detection sensor rather than to a
>>viewfinder)
>
>
> Did you ever see the mechanics of a mirror? The focussing mirror IS
> much much smaller than the main one. It is NOT doing the same job.

You will require more than one and for the complexity of using the
fastest AF focusing method in all lighting conditions and having more
than just a single AF point, you will have one for each sensor

> Reflecting away the center 30% of the image is NOT the same as
> reflecting away 99% of the image; so the secondary mirror may be about
> 2x smaller. Moreover, the secondary mirror does not need to cover the
> focusing screen, which is yet another restriction on the size of the
> primary mirror.

You have failed yet again to comprehend what I've written.
It you insist on having PD sensor mirrors, then they will obscure part
of the imaging sensor (which is why all of the DSLR cameras with
live-view must lower their reflex mirror to focus)

>>Or, you could have a pelical mirror (look up the Canon Pelix or EOS RT)
>>for your phase detection sensors and put up with losing at least 1 stop
>>of brightness at the imaging sensor.
>
>
> There is no hard limit on transparency of a pelican. So it may be 1
> stop, or 0.1 stop lost. The minimal eV would depend on the design of
> the focussing system; with better design, you can have better
> transparency with the same minimal-eV-of-focussing.

If you want a usable amount of light to go anywhere other than the
imaging sensor, you will be losing a considerable amount of brightness
in the image focused onto the imaging sensor.
There is (as yet) no way around the physics of it.

>>I don't see the point of going to all this complexity and not having an
>>optical TTL viewfinder.
>
>
> LOL! Of course, if you forget about inferior optic, no way to take
> movies, no tilt-screen focussing, no convenient low-light view,
> weight, cost, the vibration-blur, (etc?) then there may be no point
> indeed...

Of course, this would only be valid for your mythical multi-megapixel EVF.
Otherwise you will be sacrificing the best viewfinder (no jaggies, no
lag, no red/green/blue speckling in low light, etc) for a few gimmicks
which don't actually require an EVF to pull off.
 >> Stay informed about: Fuji's DSLR killer 

mark.thomas.7 DeleteThis @gmail.com wrote:
>
> If they can get those areas working well, that pretty much just leaves
> the EVF... when are bridge camera makers going to listen to all the
> suggestions to supply a high-res EVF? I'd happily sacrifice a little
> weight and bulk for a better viewfinder, even if monochrome...!

My D300 has a 1920x480 dot EVF....
 >> Stay informed about: Fuji's DSLR killer