When will electonic viewfinders improve?

Right now, in some instances using non-autofocusing long lenses,
they are very poor for trying to focus. What is needed are
finer pixels in these things. I'm wondering if they've reached
a wall since I've seen no improvement in viewscreens in five years.
-Rich

RichA wrote:

Right now, in some instances using non-autofocusing long lenses,
they are very poor for trying to focus. What is needed are
finer pixels in these things. I'm wondering if they've reached
a wall since I've seen no improvement in viewscreens in five years.
-Rich

Monitors are poor ways to focus a shot, and on most (all?) SLR's you can't
anyway as the scene is directed up to the optical viewfinder. This has always
been the great advantage with SLR: the viewfinder shows you the scene as it will
be recorded including focus and DOF (if DOF preview equipped).

Optical viewfinders since AF came along have become a little bit less accurate
than the 70's ish split prism manual focus which is very accurate.

The viewscreen on the Maxxum 7D is 207,000 pixels, but also larger. IAC, there
is no way to image the scene with the shutter closed and mirror down.

The EVF on the Dimage A2 is about 922,000 pixels, so perhaps focus is possible
there to greater accuracy.

http://www.dpreview.com/news/0402/04...tadimagea2.asp

Cheers,
Alan

--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: there's no such thing as a FreeLunch.

On Sun, 19 Dec 2004 15:49:03 -0500, Alan Browne
wrote:

RichA wrote:

Right now, in some instances using non-autofocusing long lenses,
they are very poor for trying to focus. What is needed are
finer pixels in these things. I'm wondering if they've reached
a wall since I've seen no improvement in viewscreens in five years.
-Rich

Monitors are poor ways to focus a shot, and on most (all?) SLR's you can't
anyway as the scene is directed up to the optical viewfinder. This has always
been the great advantage with SLR: the viewfinder shows you the scene as it will
be recorded including focus and DOF (if DOF preview equipped).

Optical viewfinders since AF came along have become a little bit less accurate
than the 70's ish split prism manual focus which is very accurate.

The viewscreen on the Maxxum 7D is 207,000 pixels, but also larger. IAC, there
is no way to image the scene with the shutter closed and mirror down.

The EVF on the Dimage A2 is about 922,000 pixels, so perhaps focus is possible
there to greater accuracy.

http://www.dpreview.com/news/0402/04...tadimagea2.asp

Cheers,
Alan

Interesting looking new camera. The "apochromatic" lens is a
question. True apochromatism means three primary colours infocus
at one point = no colour error, but I'll believe it when I see it
as all these prosumers have noticeable chromatic aberration.
-Rich

Alan Browne wrote:
[]
The EVF on the Dimage A2 is about 922,000 pixels, so perhaps focus is
possible there to greater accuracy.

Be aware that these are Sigma-Pixels (TM)! Each RGB is counted
separately. It's actually a 640 x 480 VGA display - just 307200 RGB
pixels.

David

David J Taylor posted:
Dimage A2

Like to confirm that with a link?

--
Petros
Ap' ola prin ipirche o Logos

David J Taylor posted:
Alan Browne wrote:
[]
The EVF on the Dimage A2 is about 922,000 pixels, so perhaps focus is
possible there to greater accuracy.

Be aware that these are Sigma-Pixels (TM)! Each RGB is counted
separately. It's actually a 640 x 480 VGA display - just 307200 RGB
pixels.

David

Sorry for the previous post, my bad.

--
Petros
Ap' ola prin ipirche o Logos

RichA wrote:



Interesting looking new camera. The "apochromatic" lens is a
question. True apochromatism means three primary colours infocus
at one point = no colour error, but I'll believe it when I see it
as all these prosumers have noticeable chromatic aberration.


APO does not mean eliminates chromatic aberation, but it does of course reduce
it significantly. There are many APO lenses out there, I have three (1 prime, 2
zooms).

Cheers,
Alan


--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: there's no such thing as a FreeLunch.

David J Taylor wrote:

Alan Browne wrote:
[]

The EVF on the Dimage A2 is about 922,000 pixels, so perhaps focus is
possible there to greater accuracy.


Be aware that these are Sigma-Pixels (TM)! Each RGB is counted
separately. It's actually a 640 x 480 VGA display - just 307200 RGB
pixels.


Good point. I've go to read the fine print!

I wonder why the claim 922K pixels then? The Minolta site says:

"The A2’s 922,000-pixel TFT LCD delivers clear images and sharp, contoured
information."

Are the R,G,B's spatially separated? If so, then it is little different than
calling an 8MPix R,G,B sensor 8 Mpix.

Cheers,
Alan


--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: there's no such thing as a FreeLunch.

But that isn't the viewfinder that is the LCD screen. The viewfinder is the
thing you put your eye up to and look through. Not all of them are LCD
screens, very few of dSLR are. The ones I have seen (point and shoot) are
pretty sucky. But one should not confuse the viewfinder with the LCD screen.

John


"Alan Browne" wrote in message
...
David J Taylor wrote:

Alan Browne wrote:
[]

The EVF on the Dimage A2 is about 922,000 pixels, so perhaps focus is
possible there to greater accuracy.


Be aware that these are Sigma-Pixels (TM)! Each RGB is counted
separately. It's actually a 640 x 480 VGA display - just 307200 RGB
pixels.


Good point. I've go to read the fine print!

I wonder why the claim 922K pixels then? The Minolta site says:

"The A2’s 922,000-pixel TFT LCD delivers clear images and sharp, contoured
information."

Are the R,G,B's spatially separated? If so, then it is little different
than calling an 8MPix R,G,B sensor 8 Mpix.

Cheers,
Alan


--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: there's no such thing as a FreeLunch.

On Mon, 20 Dec 2004 13:51:04 -0500, Alan Browne
wrote:

RichA wrote:



Interesting looking new camera. The "apochromatic" lens is a
question. True apochromatism means three primary colours infocus
at one point = no colour error, but I'll believe it when I see it
as all these prosumers have noticeable chromatic aberration.


APO does not mean eliminates chromatic aberation, but it does of course reduce
it significantly. There are many APO lenses out there, I have three (1 prime, 2
zooms).

Cheers,
Alan

This guy sells telescope optics that make Zeiss camera lenses look bad
by comparision:

Defining Apochromatism
by Thomas Back

Updated 6-29-03

With the proliferation of apochromatic refractors that are available
to the amateur astronomer, it is time to define the parameters of a
true apochromatic objective lens. The modern definition of
"apochromat" is the following: An objective in which the wave
aberrations do not exceed 1/4 wave optical path difference (OPD) in
the spectral range from C (6563A - red) to F (4861A - blue), while the
g wavelength (4358A - violet) is 1/2 wave OPD or better, has three
widely spaced zero color crossings and is corrected for coma.