Just for completeness, here is the link to the "add noise to
make D2x image more film like" post in DPreview forums:
http://forums.dpreview.com/forums....3552930I only mentioned that to my eyes the added noise made
the image look more natural. This has nothing to do
with the general quality of DPreview forum discussions,
to anyone with a sound sense of logic. At least nothing
was labeled "bull" in the DPreview forum...
Don't take me wrong that I shoot both film and digital
and I have been speaking with my experiences with
Lightjet/Chromira printing which is already more
tolerate to digital artifacts than inkjet. Raw conversion
algorithm and post processing are crutial to the image's
feel, both on screen and on prints, which makes the D2x
images much more film like than those from 1DsII.
My master images has from dozens to near hundred of
local contrast enhansing masked layers which applies
to both film and digital images, from the process I learn
the limitations of the both technology.
Clark stated clearly that there are huge resolution gap
between B&W, color negative, and pro slide films, and I
agree both the D2x and 1DsII are beyond the 645 print
film level. However for Velvia it is very different. What
made me speak was nothing but Michael's stretch that
the P45 will beat scanned 8x10 in all cases. Again this
is a discussion group of landscape photography, and
over 90% of the film based landscape photographer
shoot chromes not negatives.
Look again at Michael's 1Ds vs. Pentax 67 comparison:
http://www.luminous-landscape.com/reviews/shootout.shtmlHe first said the digital crop appears to have lower
resolution because it is enlarged too much to match the
scanned film crop. Two paragraph later he concluded
that the 1Ds has a better resolution than the scanned
chrome. Maybe this is just the logic and science of the
new age?
Drum scans emphersize film grains. Try the Imacon
FlexTight 949 where they made improvement over
848/646 to make the grains much less visible while
retain the image details. Their FlexTouch software
dust and scratch removal feature is better than
digital ICE and does not slow the scans down, based
on my experience too, so my scanned skys are almost
as clean as those from digital.
I am a medical imaging expert working in a major R&D
lab. What I learned is that any sharp cut of the long
response curve tail, be it the spatial frequency expressed
in MTF, or a natural sound's extended harmonic structure,
creates unnatural artifacts. Lens and film both have long
MTF tails, and the 10um grain size is the statistical mean
not the size smallest contributing elements. As I mentioned
it is exactly why after 20 years audio engineers are learning
the 40-80KHz components are so crutial to the base tone
definition and impact making wavefront building so that their
inclusion in SACD or DVD-A are essential -- our ear can not
hear the pure harmonics but our skin will certainly feel the
sharper rising edge of the air pressure change. The abrupt
cut of the MTF in digital capture at the Nequist frequency
(as well as the total artifacts beyond that) has a similar
effect to the normal CD's abrupt cut of the audio frequency
at 20kHz, which contributes to their harsh sounding well
known to many (not the MP3 generation).
The 30% resolution lost from Bayer interpolation is statistical,
and as with any statistics there are exceptions. For an example
of interpolation failure checkout Clark's color pattern capture
comparisons:
http://www.clarkvision.com/imagedetail/fil...xl.digital.htmlBye everyone.
Best regards,
Leping Zha, Ph.D.
www.lepingzha.com