Fuji's DSLR killer

dj_nme wrote:
[]
> That's not the point, even at 640x480 the EVF isn't a proper
> substitute for an optical TTL viewfinder.
> The EVF image is still too coarse to manualy focus without a 4x focus
> zoom assist when the focus ring is turned.
> I had a KM A2 for a brief period before giving it to my dad and
> buying a Pentax *ist-DS instead, the improvement in the EVF in the
> Dimage A2 wasn't enough compared to that in my old 7Hi for me to put
> with for more than a few photo outings.
> It just didn't live up to the hype.

I was actually quite pleased with the A2 viewfinder I used for a short
while. I can't recall whether the A2 had the same feature as the
Panasonic FZ20 - automatic zoom of the viewfinder when the focus ring was
twisted. I agree that it's still way below the optical viewfinder in a
DSLR.

Cheers,
David
 >> Stay informed about: Fuji's DSLR killer 

David J Taylor wrote:
> dj_nme wrote:
> []
>> That's not the point, even at 640x480 the EVF isn't a proper
>> substitute for an optical TTL viewfinder.
>> The EVF image is still too coarse to manualy focus without a 4x focus
>> zoom assist when the focus ring is turned.
>> I had a KM A2 for a brief period before giving it to my dad and
>> buying a Pentax *ist-DS instead, the improvement in the EVF in the
>> Dimage A2 wasn't enough compared to that in my old 7Hi for me to put
>> with for more than a few photo outings.
>> It just didn't live up to the hype.
>
> I was actually quite pleased with the A2 viewfinder I used for a short
> while. I can't recall whether the A2 had the same feature as the
> Panasonic FZ20 - automatic zoom of the viewfinder when the focus ring was
> twisted. I agree that it's still way below the optical viewfinder in a
> DSLR.

One of the first implementations of live view on a DSLR was a Canon
model specifically for astronomy, to aid focusing, so it definitely can
work when you zoom in on full pixels though it would be awkward for
anything but tripod work. I was playing with live view on a D300 and was
rather disappointed that it did not zoom in as far as you can after
taking the photo.
 >> Stay informed about: Fuji's DSLR killer 

[A complimentary Cc of this posting was NOT [per weedlist] sent to
dj_nme
<dj_nme.TakeThisOut@iinet.net.au>], who wrote in article <479ecde8$0$9719$5a62ac22@per-qv1-newsreader-01.iinet.net.au>:
> >>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.

As I said, what is "usable" is determined by the relative sensitivity
(and exposure time) for the main sensor, and the parallax sensor.
Making a more sensitive parallax sensor would allow almost-transparent
pelicans.

> >>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.

Sure. As I said, I expect that they are very affordable today. [Did
you see tiny Sony SVGA pocket PCs?]

> Otherwise you will be sacrificing the best viewfinder (no jaggies, no
> lag, no red/green/blue speckling in low light, etc)

which is very dim, no focus assist, no instant magnification, no way
to see how the image would like when the aperture is wide open, etc...

> for a few gimmicks which don't actually require an EVF to pull off.

Yeah, this is why we see what I listed above on dSLRs so often...

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

dj_nme wrote:
> What, you mean the opposite of the grainy and slow refreshing EVFs that
> are currently in use?
> Sony has gone and made the best implementation of LCD live-view in any
> DSLR camera so far, on the Alpha 350:
> <http://www.dpreview.com/news/0801/08013003sonyalpha1st.asp>
> This seems to be the best of both worlds, optical TTL eye-level
> viewfinder and an LCD live-view which preserves AF for use out of
> position (eg: over/around obstacles) when you can't see through the
> viewfinder.

It sounds to me like Sony is starting the same marketing proposition
they use in their other product lines. Create four or five models that
are almost identical, but each one is missing a single feature. Make it
impossible to get a unit with every one of the features you want.
Install rootkit. (OK, I'm just guessing about that last one.)
 >> 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 <47a17688$0$9736$5a62ac22@per-qv1-newsreader-01.iinet.net.au>:
> >>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.

> > Get some clue! Distance meters USE parallax to measure the distance.

> There has been that "whooshing" noise of concepts flying over your head
> again!

Please do not hesitate to continue feeling that you are smarter than
the others if it makes you feel better.

> If the RF mechanism is not a TTL type (eg: phase detection or
> contrast detection), then there will definitely be parallax between
> the RF and the imaging lens.

Sure. And this parallax is what can allows the camera to find the
distance to the subject.

> Distance from RF window to taking lens equals paralax.

I think that what you are missing is the fact that there are two kinds
of parallax in this discussion. One is is parallax which is the angle
from the reference point to two sensors (e.g., one behind the lens,
one ancillary; or two ancillary sensors). It is a "good parallax",
which allows the camera to find the distance to the reference point.

Another parallax is the angle between the axis of the lens, and the
direction to the reference point (assuming "center focussing point").
It is a "bad" parallax, which one wants to avoid. Having a live
view sensor allows one to eliminate *this* "bad parallax" by knowing
the position of the reference point w.r.t. the axis.

> This proposed method would require quite complex image processing and
> would be glacially slow as a result.

Year, right. Next, you are going to tell me that autofocus
rangefinders are "glacially slow", or optical mice require "complex
image processing". [There is no much difference between the needed
algo, and what is easily done today.]

> Current pattern recognition has difficulty when faced with known objects,

Get a clue. To find parallax, all you need is correlators, not
pattern recognizers.

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

[A complimentary Cc of this posting was NOT [per weedlist] sent to
Ilya Zakharevich
<nospam-abuse.DeleteThis@ilyaz.org>], who wrote in article <fnheb6$1vai$1@agate.berkeley.edu>:
> The idea of dSLR it a zombie; it does not know it is already dead. It
> would be really dead the moment a good way to focus without a
> secondary mirror is invented. (I'm pretty sure that already today cheap
> EVFs are possible which are [in most usages] more convenient than
> reflex-viewfinders. As Minolta A2 teaches us, even 1024x786x3 with
> instant 2x/4x magnification would be better...)

Actually, these numbers (in 1024x786x3) were just "a guts feeling".
But now I looked at the angular size of viewfinder's image of a dSLR;
I checked one, and it is below 15x10 degrees. Taking 1' resolution,
this gives 900x600 pixels; this is definitely not the world's best
viewfinder, but others I saw gave image quite similar in size. I'm
surprised how good it fits the "guts feeling"...

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

[A complimentary Cc of this posting was NOT [per weedlist] sent to
Ilya Zakharevich
<nospam-abuse RemoveThis @ilyaz.org>], who wrote in article <fo1q1h$16sm$1@agate.berkeley.edu>:
> [A complimentary Cc of this posting was NOT [per weedlist] sent to
> Ilya Zakharevich
> <nospam-abuse RemoveThis @ilyaz.org>], who wrote in article <fnheb6$1vai$1@agate.berkeley.edu>:
> > The idea of dSLR it a zombie; it does not know it is already dead. It
> > would be really dead the moment a good way to focus without a
> > secondary mirror is invented. (I'm pretty sure that already today cheap
> > EVFs are possible which are [in most usages] more convenient than
> > reflex-viewfinders. As Minolta A2 teaches us, even 1024x786x3 with
> > instant 2x/4x magnification would be better...)
>
> Actually, these numbers (in 1024x786x3) were just "a guts feeling".
> But now I looked at the angular size of viewfinder's image of a dSLR;
> I checked one, and it is below 15x10 degrees. Taking 1' resolution,
> this gives 900x600 pixels; this is definitely not the world's best
> viewfinder, but others I saw gave image quite similar in size. I'm
> surprised how good it fits the "guts feeling"...

Oups, should not have postted in a middle of a night... The size is
more like 23x15 degrees; so one needs an angular resolution of 1.4' to
match about 1024x768 pixels... So in bright light, eye has a better
resolution than 1024x768 display at this angular size; in dim light,
they should be on par; and, of course, with 1024x768x4 one might be
able to play games with subpixelization to improve efficient
resolution...

Sorry for the error,
Ilya
 >> Stay informed about: Fuji's DSLR killer 

In article <47a44a4e$0$9779$5a62ac22@per-qv1-newsreader-
01.iinet.net.au>, dj_nme says...

> Sony has gone and made the best implementation of LCD live-view in any
> DSLR camera so far, on the Alpha 350:
> <http://www.dpreview.com/news/0801/08013003sonyalpha1st.asp>
> This seems to be the best of both worlds, optical TTL eye-level
> viewfinder and an LCD live-view which preserves AF for use out of
> position (eg: over/around obstacles) when you can't see through the
> viewfinder.

There are some major problems with the approach Sony chose:

1. Misalignments/mismatches are possible between the image in the
viewfinder and the image the (main) sensor really captures. With a live
video feed from the main sensor this is ruled out from the beginning.

2. No live histogram possible

3. In case the focus plane is mismatched between main sensor and AF
system (unlikely, but could happen as a result of production errors or
errors which accumulate over time), you will not see this in the live
preview.
--

Alfred Molon
------------------------------
Olympus 50X0, 8080, E3X0, E4X0, E5X0 and E3 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site
 >> Stay informed about: Fuji's DSLR killer 

mark.thomas.7.DeleteThis@gmail.com wrote:

<edited for brevity>

> 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...!


Hello, Mark:

Could OLED ("organic light-emitting diode") displays be the ultimate
solution, to the EVF resolution issues?


Cordially,
John Turco <jtur.DeleteThis@concentric.net>
 >> 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 <47a17688$0$9736$5a62ac22@per-qv1-newsreader-01.iinet.net.au>:
>
>>>>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.
>
>
>>>Get some clue! Distance meters USE parallax to measure the distance.
>
>
>>There has been that "whooshing" noise of concepts flying over your head
>>again!
>
>
> Please do not hesitate to continue feeling that you are smarter than
> the others if it makes you feel better.
>
>
>>If the RF mechanism is not a TTL type (eg: phase detection or
>>contrast detection), then there will definitely be parallax between
>>the RF and the imaging lens.
>
> Sure. And this parallax is what can allows the camera to find the
> distance to the subject.

You've (yet again) missed the point, if the RF is a seperate unit to the
imaging lens then there will be BAD parralax between the imaging lens
and the RF mechanism.
No way around it, no matter how you squirm.

This is the reason that Leica made parralax correction attachments for
clos-in/macro work, one of them are the "eyes" on the wide-angle lenses
and another type was the the VisoFlex attachment (esentially turning a
Leica RF camera into a crude SLR camera).

>>Distance from RF window to taking lens equals paralax.
>
>
> I think that what you are missing is the fact that there are two kinds
> of parallax in this discussion. One is is parallax which is the angle
> from the reference point to two sensors (e.g., one behind the lens,
> one ancillary; or two ancillary sensors). It is a "good parallax",
> which allows the camera to find the distance to the reference point.
>
> Another parallax is the angle between the axis of the lens, and the
> direction to the reference point (assuming "center focussing point").
> It is a "bad" parallax, which one wants to avoid. Having a live
> view sensor allows one to eliminate *this* "bad parallax" by knowing
> the position of the reference point w.r.t. the axis.

You have failed yet again, keep up the "good" work.
A rangefinder is a mechanism for determining distance (ie: range) to an
object, so if it is not using the imaging lens as part of it then there
will be a difference between what the RF is pointed at and what the
imaging lens is pointed at.
That is the simple fact of it.
No way around it.

>>This proposed method would require quite complex image processing and
>>would be glacially slow as a result.
>
>
> Year, right. Next, you are going to tell me that autofocus
> rangefinders are "glacially slow", or optical mice require "complex
> image processing". [There is no much difference between the needed
> algo, and what is easily done today.]

You are confusing merely looking for change with something else.
Get a clue.

>>Current pattern recognition has difficulty when faced with known objects,
>
>
> Get a clue. To find parallax, all you need is correlators, not
> pattern recognizers.

The whoshing sound yet again occurs and I get yet another laugh at your
expense.
Wonderful!
 >> Stay informed about: Fuji's DSLR killer 

[A complimentary Cc of this posting was NOT [per weedlist] sent to
dj_nme
<dj_nme.TakeThisOut@iinet.net.au>], who wrote in article <47a45001$0$9759$5a62ac22@per-qv1-newsreader-01.iinet.net.au>:

> if the RF is a seperate unit to
> the imaging lens then there will be BAD parralax between the imaging
> lens and the RF mechanism.

Not if a live view sensor behind the lens is a PART OF rangefinder.

> A rangefinder is a mechanism for determining distance (ie: range) to an
> object, so if it is not using the imaging lens as part of it then there
> will be a difference between what the RF is pointed at and what the
> imaging lens is pointed at.

Again, you missed the fact that the live view sensor may be a part of
a rangefinder.

Since all these points were already fully discussed in the preceding
part of this thread, I do not see any point in repeating the rest. If
still do not understand some parts, feel free to ask questions.

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

John Turco wrote:
> mark.thomas.7.RemoveThis@gmail.com wrote:
>
> <edited for brevity>
>
>> 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...!
>
>
> Hello, Mark:
>
> Could OLED ("organic light-emitting diode") displays be the ultimate
> solution, to the EVF resolution issues?

Ha, I'd never heard of that... imagining a bluetooth eyeglasses
viewfinder: http://www.gizmag.com/go/7379/
 >> 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 <47a44a4e$0$9779$5a62ac22@per-qv1-newsreader-01.iinet.net.au>:
<snip>
>>With a SLR you are always focusing with the apeture wide open.
>
>
> Do you change the focusing screen each time you change a lens?

This bit is non-sensical and irrelevent.

> If
> your focusing screen does not exactly match the f-stop of open lens,

A focus screen has no f-stop, it's not a lens element.

> then you either get a very dim picture, or a picture which takes light
> only from near the axis of the lens.

In that case, the image recorded on the film or sensor would be equally
dim, which is also quite non-sensical.
Open aperture composing and focusing is how it has done (and continues
to be done) with all slr cameras since it was introduced with the Contax
S in 1949.

Your wacky ideas never cease to amuse.
 >> Stay informed about: Fuji's DSLR killer