When will electonic viewfinders improve?

On Tue, 21 Dec 2004 09:35:13 -0000, "David J Taylor"
wrote:

John Doe wrote:
"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

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

On that camera, the 922,000 pixels is the EVF (there is no conventional
finder). It's actually not too bad to use.

David


Kind of tough to use in broad daylight.
-Rich

On Mon, 20 Dec 2004 23:07:30 -0500, Alan Browne
wrote:

RichA wrote:

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:

I won't challenge that statement as I'm more ignorant about telescope optics
than Zeiss optics... and I'm pretty ignorant there too...

The fellow below does say enough to show that even if his optics are fantastic
APO's, they cannot possibly correct every wavelength of light coming through the
pipe. There will be some perfect matches, and many-many very-very close, but
not perfect.

Cheers,
Alan

They do their best, but the fastest lens set I've seen that was
truly apochromatic was about f5. Faster than that and it's very
difficult or impossible with current technology.
-Rich



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.

In article , Alan Browne
wrote:

David J Taylor wrote:


I'm afraid I'm not familiar with "twinkies".
I sounds slightly rude, I'm sure it isn't!

Crappy chocalate cakes from a vending machine. US actually. Here it would
be
"May West" or "Joe Louis"... crap just the same. I never ate many myself,
more
coke or coffee ... not much coke actually, just too much coffee and chocolate
bars.

twinkies are the sponge cake with cream filling, not the chocolate
cakes (which are ding dongs i think).

http://www.twinkies.com/index.asp

and of course, someone is ebaying some:
http://cgi.ebay.com/ws/eBayISAPI.dll...310&item=43449
14548&rd=1

http://i23.ebayimg.com/03/i/03/0e/b0/09_1_b.JPG

RichA wrote:

Kind of tough to use in broad daylight.

You look at it via a viewfinder, like on a an SLR. eg: the camera has two
monitors, the on the back and the one in the VF. Strange, but true.

http://www.dpreview.com/reviews/koni...taa2/page2.asp


--
-- 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.

nospam wrote:


twinkies are the sponge cake with cream filling, not the chocolate
cakes (which are ding dongs i think).

Thanks for confirming my inexpertise in the matter.



--
-- 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.

RichA wrote:
[]
On that camera, the 922,000 pixels is the EVF (there is no
conventional finder). It's actually not too bad to use.

David


Kind of tough to use in broad daylight.
-Rich

Why? The EVF is something you bring eye to just like an SLR viewfinder.
It doesn't suffer from sunlight reducing the display contrast.

Cheers,
David

Alan Browne wrote:
nospam wrote:


twinkies are the sponge cake with cream filling, not the chocolate
cakes (which are ding dongs i think).

Thanks for confirming my inexpertise in the matter.

I can see we all have a lot to learn! BTW: my first job was in an
electronics factory making laser equipment - it was originally the McVitie
and Price factory where Jaffa Cakes were invented! BTW: Jaffa Cakes
created a problem for the tax man. Are they taxed as biscuits or as
cakes? Different tax rates!

http://www.bbc.co.uk/dna/h2g2/alabaster/A185104

has some (possibly incorrect) information.

I can recommend Jaffa Cakes while you are waiting for your pictures to
print!

David

On Sun, 19 Dec 2004 14:27:31 -0500, 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

Thats why I bought an SLR.... couldn't see a thing in those!!

Bob wrote:
On Sun, 19 Dec 2004 14:27:31 -0500, 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

Thats why I bought an SLR.... couldn't see a thing in those!!

Do you mean for manual focus? If so, try the scheme used in the Panasonic
FZ20 and other cameras where the centre of the finder is magnified as when
focus ring is rotated. It's not perfect, but better than plain
ground-glass (as the micro-prism and split-image focussing aids may no
longer be provided in DSLRs).

Cheers,
David

In message ,
Alan Browne wrote:

But if the sptially seperated R,G,B's in the display represented spatially
seperated information from the sensor, then the spatially seperated information
in the display would be 0.9M.

... and how then, do you represent full luminance in a blue cell?
--


John P Sheehy