----- Original Message -----
From: "Joe Gwinn" <joegwinn@xxxxxxxxx>
>
> If all colors don't contribute equally, one gets color noise, so one
cannot just count the total pixels regardless of their color.
>
May be you are right, I have no test sample support here.
> >That is the point and I heard long ago in DC news group that some
> >professional photography (at least they said they live on this) think
> >their "new" Nikon 990 is better than their Hass for studio portrait on
> >output quality.
>
> One wonders how this can be so...
>
It was two years ago in rec.photo.digital, he did show us some stunning
portraits. I think you don't need a high resolution system for portrait.
Good skin tone, low (no) noise, right among of sharpening... that is good
enough. Instant result/re-shoot is also important, just like taking Polaroid
in MF. BTW, everyone have tried DC to inkjet will agree good quality print
is very easy to achieve.
> >The test was performed in around 1990 to test the performance of my
> >Zuikos, all shots were taken at around 1:50 or something similar. To
> >interpret it is easy, you should download it in photo editing
> >software, there should be dimension information on your software.
> >Check which point you think you can still identify the lines. I would
> >say at least the "200" position. Measure the width of this group of
> >lines, there is total 15lp and at the point "200" the width is 0.2mm,
> >so 5*15=75lp/mm.
>
> Ah. The markings are the width in microns.
>
It is just an incident, as I mentioned size information is available in
PhotoShop and other softwares, use the tool make the measurment (e.g
selecting tool). In PhotoShop you have to set the measurement unit to "cm"
first.
>
> The most basic test of resolution is to photograph a high-contrast knife
edge, and then to measure the illumination versus distance (perpendicular to
the edge) function. The film will win in the present test case, ecen though
the film is somewhat noiser (grainier).
>
Ok, even film has an edge it is very small. Also, I have to mention the test
background, I just try to use a most common good quality film with a normal
sence to simulate how we are using our equipment daily. The Zuiko I used
for the test is two very best one and they won't be poorer than fix lens in
resolution.
>
> If one reduces the exposure, the blooming should be reduced, while the
>linearity and dynamic range of the CCD allow shadow detail to be retained,
>as the theory goes. So, in the experiments, it might be useful to bracket
>by one and two stops, for the experience. I guess the problem will be the
>noise in the shadows.
Yes, you are right, reduces exposure will help and the problem will happen
in "very" strong spot light. I will try to make a comparison later. May be
I'm able to find some night scene samples shot in the pass.
C.H.Ling
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