"Moire Effect" - Camera to Offset Lithography - Important Defect?

In article , G.T.
wrote:

b) People competent in digital imaging risk high blood pressure by
reading his explanations of how things work. Among the
risks associated with high blood pressure are stroke, heart
attack, acid reflux disease, and shortened life span.

sigh In my initial post in this thread, I informed everyone that I
was a beginner.

They all know what they are getting into when they read a beginner's
posts, as all beginners are bound to have wrong ideas about how things
work.

I posted all my beliefs about "how things work" up front, which is lot
better than keeping those wrong beliefs bottled up and under wraps,
where they can bite me later, and bite all the people who rely on me.

They constructively and without ridicule, changed my mind about "how
things work".

Sure, they had to put up with my wrong ideas for a period of time,
which was no fun. It placed a burden upon them, but they persisted
and actually did some good in this world.

I am sure this gave them a sense of accomplishment, a euphoria which
released life prolonging hormones in their systems.

You on the other hand, deal in disruption, ridicule, off-subject
trolling, false accusations, and myriad other negative things, which
will shorten your life and the lives of all the people who believe the
one-sided poison you spread.

Mark-

Mark Conrad wrote:
In article , G.T.
wrote:


b) People competent in digital imaging risk high blood pressure by
reading his explanations of how things work. Among the
risks associated with high blood pressure are stroke, heart
attack, acid reflux disease, and shortened life span.


sigh In my initial post in this thread, I informed everyone that I
was a beginner.

Yes, it is just a beginning in a way. The beginning of driving everyone
on r.p.d.s-s. insane, just like on comp.sys.mac.system.


They all know what they are getting into when they read a beginner's
posts, as all beginners are bound to have wrong ideas about how things
work.

I posted all my beliefs about "how things work" up front,

Why? Why not keep it to a simple question without introducing your
"wrong ideas"?

which is lot
better than keeping those wrong beliefs bottled up and under wraps,

How is that?

where they can bite me later, and bite all the people who rely on me.

Well, if you read and comprehend the responses here then they won't bite
you later.


They constructively and without ridicule, changed my mind about "how
things work".

Well, like you said, you're a beginner. After you incessantly post your
misinterpretations and refuse to understand people who are trying to
help you then I'm sure you'll start receiving curt replies like from
those on c.s.m.s. who have grown weary of you.


Sure, they had to put up with my wrong ideas for a period of time,
which was no fun. It placed a burden upon them, but they persisted
and actually did some good in this world.

Yes, there is a lot to learn from good folks like JPS and Gisle and
others here.


I am sure this gave them a sense of accomplishment, a euphoria which
released life prolonging hormones in their systems.

I wouldn't go that far.


You on the other hand, deal in disruption, ridicule, off-subject
trolling, false accusations, and myriad other negative things, which
will shorten your life and the lives of all the people who believe the
one-sided poison you spread.


Hey, I'm not the one that created the FAQ nor have I contributed to it.

Greg

--
"All my time I spent in heaven
Revelries of dance and wine
Waking to the sound of laughter
Up I'd rise and kiss the sky" - The Mekons

In article , G.T.
wrote:

sigh In my initial post in this thread, I informed everyone that I
was a beginner.

Yes, it is just a beginning in a way. The beginning of driving everyone
on r.p.d.s-s. insane, just like on comp.sys.mac.system.

Your ridiculous opinion, your trolling insult to me, off topic and a
waste of everyone's time in this thread.


I posted all my beliefs about "how things work" up front,

Why? Why not keep it to a simple question without introducing your
"wrong ideas"?

Read the thread instead of going off half-cocked.

The responders to my initial post maintained that patterns had to be in
the scene to trigger the Moire effect.

At the time I thought they were not correct, which is _why_ I posted
my ideas about how the Moire effect worked.

The Moire effect is difficult to understand, especially for a beginner
in digital photography like me.

Any Google search for "Moire effect" will turn up a lot of high powered
scientists who try to explain the effect in their own language.

I read that stuff, and thought I understood how Moire worked.

I posted how I thought it worked. None of the followup responders had
Moire bother them in the plain non-pattern areas of their scenes, areas
like a clear blue sky.

That response from them caused me to doubt my understanding, so I went
back to my Google sources and re-read them. It is not easy to
comprehend that stuff, try it yourself if you don't believe me.

It appeared I was wrong, so I apologized to all.

If I had not posted my ideas, some of the followup posts might never
have been posted. My ideas about how Moire works would remain flawed,
and my attempts to eliminate Moire defects by buying the right hardware
and software would be doomed to failure.

Posting my beliefs here, and the good responses here, eliminated the
bad things that would likely have happened if I had _not_ posted my
beliefs, and asked questions.


I would not have to waste my time and everyone else's time here, if you
could figure that out for yourself.



which is lot better than keeping those wrong beliefs
bottled up and under wraps,

How is that?

Because like I posted to you earlier, wrong ideas can hurt the person
who has them, and also hurt the people who interact with the guy with
the wrong beliefs, that _you_ advocate be kept under wraps.

A good illustration of this are the "wrong beliefs" that arabs have.

They obviously share your idea that "wrong beliefs" should be kept
under wraps, never exposed to the light of day.

Their "wrong beliefs" certainly have caused us a lot of misery.



where they can bite me later, and bite all the people who rely on me.

Well, if you read and comprehend the responses here
then they won't bite you later.

I _did_ read and comprehend their responses, as is obvious by my
re-checking of the Google sources, changing my beliefs, and posting
that my initial beliefs were wrong - - - so what are you bellyaching
for, other that to raise another straw man and waste everyone's time.
Is that your intent?



They constructively and without ridicule, changed my mind about "how
things work".

Well, like you said, you're a beginner. After you incessantly post
your misinterpretations and refuse to understand people who are
trying to help you then I'm sure you'll start receiving curt
replies like from those on c.s.m.s. who have grown weary of you.

Yep, that answers my own previous question, you _do_ intend to troll
here and waste everyone's time.


Yes, there is a lot to learn from good folks like JPS and Gisle and
others here.

Yes, and that compliment shows you are not all bad.



I am sure this gave them a sense of accomplishment, a euphoria which
released life prolonging hormones in their systems.

I wouldn't go that far.

I would. Whenever I help people, I get a good feeling. Others here
get that same good feeling, otherwise they would not take the time and
trouble to help me.



You on the other hand, deal in disruption, ridicule, off-subject
trolling, false accusations, and myriad other negative things, which
will shorten your life and the lives of all the people who believe the
one-sided poison you spread.


Hey, I'm not the one that created the FAQ nor have I contributed to it.

What's the difference, you spread that misleading FAQ around every
chance you get. You "contribute to it" every time you post that crap.

Mark-

Mark Conrad wrote:
In article , G.T.
wrote:


sigh In my initial post in this thread, I informed everyone that I
was a beginner.

Yes, it is just a beginning in a way. The beginning of driving everyone
on r.p.d.s-s. insane, just like on comp.sys.mac.system.


Your ridiculous opinion, your trolling insult to me, off topic and a
waste of everyone's time in this thread.



I posted all my beliefs about "how things work" up front,

Why? Why not keep it to a simple question without introducing your
"wrong ideas"?


Read the thread instead of going off half-cocked.

The responders to my initial post maintained that patterns had to be in
the scene to trigger the Moire effect.

At the time I thought they were not correct, which is _why_ I posted
my ideas about how the Moire effect worked.

Yep, same old "Mark Conrad", never satisfied the first time someone
tries to explain something to you. How many years did it take those on
c.s.m.s. to explain SSH to you?


The Moire effect is difficult to understand, especially for a beginner
in digital photography like me.

Yes, it is. So why pollute Usenet with your misconceptions?


Any Google search for "Moire effect" will turn up a lot of high powered
scientists who try to explain the effect in their own language.

I read that stuff, and thought I understood how Moire worked.

I posted how I thought it worked. None of the followup responders had
Moire bother them in the plain non-pattern areas of their scenes, areas
like a clear blue sky.

That response from them caused me to doubt my understanding, so I went
back to my Google sources and re-read them. It is not easy to
comprehend that stuff, try it yourself if you don't believe me.

Gisle's sample quite clearly shows it's pattern related. You seriously
think that if you simply asked "What is moire?" or "When does moire show
up?" that people would mislead you and not answer the question
correctly? Are you that paranoid?


It appeared I was wrong, so I apologized to all.

If I had not posted my ideas, some of the followup posts might never
have been posted. My ideas about how Moire works would remain flawed,
and my attempts to eliminate Moire defects by buying the right hardware
and software would be doomed to failure.

Posting my beliefs here, and the good responses here, eliminated the
bad things that would likely have happened if I had _not_ posted my
beliefs, and asked questions.

Nothing wrong with questions, I still don't understand why you need to
elaborate on your misconceptions.



I would not have to waste my time and everyone else's time here, if you
could figure that out for yourself.


which is lot better than keeping those wrong beliefs
bottled up and under wraps,

How is that?


Because like I posted to you earlier, wrong ideas can hurt the person
who has them, and also hurt the people who interact with the guy with
the wrong beliefs, that _you_ advocate be kept under wraps.

So, now, like in c.s.m.s. we're going to have to post "Mark Conrad"
disclaimers so that people Googling about moire don't take your
misconceptions as truth?


A good illustration of this are the "wrong beliefs" that arabs have.

They obviously share your idea that "wrong beliefs" should be kept
under wraps, never exposed to the light of day.

Their "wrong beliefs" certainly have caused us a lot of misery.


Nice tangent.



where they can bite me later, and bite all the people who rely on me.

Well, if you read and comprehend the responses here
then they won't bite you later.


I _did_ read and comprehend their responses, as is obvious by my
re-checking of the Google sources, changing my beliefs, and posting
that my initial beliefs were wrong - - - so what are you bellyaching
for, other that to raise another straw man and waste everyone's time.
Is that your intent?


No, just a warning to the others.


They constructively and without ridicule, changed my mind about "how
things work".

Well, like you said, you're a beginner. After you incessantly post
your misinterpretations and refuse to understand people who are
trying to help you then I'm sure you'll start receiving curt
replies like from those on c.s.m.s. who have grown weary of you.


Yep, that answers my own previous question, you _do_ intend to troll
here and waste everyone's time.



Yes, there is a lot to learn from good folks like JPS and Gisle and
others here.


Yes, and that compliment shows you are not all bad.

You on the other hand, deal in disruption, ridicule, off-subject
trolling, false accusations, and myriad other negative things, which
will shorten your life and the lives of all the people who believe the
one-sided poison you spread.


Hey, I'm not the one that created the FAQ nor have I contributed to it.


What's the difference, you spread that misleading FAQ around every
chance you get. You "contribute to it" every time you post that crap.

Actually that is the very first time I have ever referenced that FAQ.
Anywhere.

I'm sure in another week you'll buy a 5D, and the week after that you'll
make a post here claiming that you're seeing moire in the skies of
your shots while twisting the words of one of the previous posters in
this thread to support your position. In fact I'll put money down on it.

Cheers,
Greg

--
"All my time I spent in heaven
Revelries of dance and wine
Waking to the sound of laughter
Up I'd rise and kiss the sky" - The Mekons

"Peter A. Stavrakoglou" wrote in message
news SNIP
The fabric example used to show the moire artifacts on Foveon's site
is almost identical to a shirt I have - even the color. I could not
reproduce much of any moire artifacts using my shirt and a Nikon
D50.

Which is to show that their representation of an issue is blown way
out of proportion, so they can offer a solution. It's a cheap
marketing trick.

How much of a real probelm is this for most DSLRs anyway?

It varies by model and by Raw-converter used. I've seen some nasty
examples from regular users on DPReview, with most examples being
fabric related and an occasional one with man-made repetitive
structures like picket fences or a mesh of some kind.

The type of color moire as sometimes seen from Bayer CFA sensors
(almost all DSLRs) can often be made somewhat less 'eye-catching' in
postprocessing. The simplest being a masked blend between the original
and a color noise removed version if the Raw converter allows to
produce that.

Bart

In article , G.T.
wrote:

Nothing wrong with questions, I still don't understand why you need to
elaborate on your misconceptions.

I was going to ignore you, because I still think of you as a disruptive
troll, with nothing constructive to bring to this thread.

However this time you raised a good issue with your statement, namely:
I still don't understand why you need to elaborate on your ...

Elaborate on my whatever.....

Misconceptions or non-misconceptions




I, and others, often "elaborate" because some things can not be
conveyed in 25 words or less.

Getting ideas across is often difficult and lengthy, due to the
limitations of language. (no graphics here, etc.)

So, because I have no tolerance for your trolling, I am going to
"elaborate" onto you, here and now.

Consider the Moire Effect, the subject of this thread.

If I use a 35mm digital camera to photograph a one-inch square
backlighted grid comprised of one-million tiny squares,
1,000 x 1,000 tiny squares on a side....

....and each of those tiny backlighted squares are alternately red,
green, blue, etc. in a regular pattern...

....and the one-inch square is 4 feet away and is being photographed
with a regular lens, _not_ a telephoto...

....well then the one-inch square object appears as a white square in
the finished photograph, assuming the exposure is adjusted to favor the
accurate rendition of the square.

The camera can not resolve the images of the individual colored
one-million tiny squares, so the net effect is that it is a
"one-inch-white-square-object", according to both the camera and your
eyes.



I now understand the Moire Effect, due mainly to the efforts of the
good people in this thread, except you of course...

The described situation changes radically, due to the Moire effect,
when a 1:1 macro lens is used to photograph the backlighted square at
life size.

If the photographer is "lucky", the individual one-million colored
squares will line up inside the camera, on the one-inch square CCD
detector, such that the image of each tiny red, green, blue, square
will precisely line up with the corresponding red, green, blue,
detector cells of the CCD.

In that happy case, the photographer will wind up with an image that
can be enlarged to accurately display all the tiny red, green, blue,
squares in their natural color. No Moire effect evident at all.

....assuming the exposure is adjusted to accurately display the
backlighted colors in the square.

However, if either the camera or the one-inch square backlighted object
were moved sidewise one-thousanths of an inch, there would no longer be
an accurate lining-up of the tiny colored squares with the sensor cells
of the CCD.

i.e., a red image would no longer fall on a red cell of the CCD,instead
it would fall on a green cell of the CCD for example, where the red
light could not be detected.

The net result in the final photograph would be that the colors would
not be detected, therefore the colors would not be displayed correctly
in an enlarged final photo'

The enlarged photo' would show very dark muddy colors of the individual
tiny colored squares.

The Moire effect struck, lousing up the final photo'


Now the above explanation of one example of how the Moire effect works,
could not be explained in much lesser detail, and still get across the
idea to anyone not familar with the Moire effect.

A different example could be used to explain the Moire banding defects,
but in that case the explanation using words would be much longer.


Nothing wrong with questions, I still don't understand why you need to
elaborate on your misconceptions.

All this _should_ contribute to your understanding of why elaboration
is necessary, when discussing complex subjects like the Moire effect.

I will grant that my initial idea of how Moire works was wrong, I
already admitted that in a previous post.

None of the respondents decided to tear into my initial wrong
explanation and show me in excruciating detail just where I was wrong
in my "logic" - - - or ridicule me for having the wrong idea, like you
would likely do.

Instead, they gently and with tact kept insisting that the Moire effect
was pattern related, causing me to doubt my logic enough to re-check my
(complicated) sources on Google, which _did_ change my mind.

If I had not posted my original wrong ideas about the Moire effect,
eventually those same wrong ideas would have caused a large waste of my
money trying to defeat Moire.

The people helping me here did good.

At the worst, others might have believed my wrong ideas about Moire,
causing _them_ to waste large amounts of money trying to defeat it.

The people helping me here did a _lot_ of good, thanks people.

(everyone except you did good. You did bad, negative, destructive
things as usual in your dealings with me)

I do not much care _why_ you act as you do, but be assured that your
goofy actions will not affect my behavior one iota. I will keep
posting detailed lengthy posts whenever I think they are needed.

Gadd, it is fun to dump this lengthy post on a destructive troll, I
hope he wasted his time reading every word,g

Mark-

Quick Input,

Nikon D70s CCD sensor is a "bayer-type" meaning the type of filter over the
photosites. This causes each photosite to capture one specific color in
alternating patterns. For a much better explaination, please read "Thom
Hogan - Complete guide to the Nikon D70 and D70s Cameras. It explains that
each photosite is capable of a differenc color rendition in an alternating
pattern. Not row by row if I read it correctly.

If Canon does the row by row photosites, this might account for the morie.
It might be present in my picutes, but I don't know what to look for and I
am just a novice anyway, so I either think a picture is good or not.

Old Man River


"Mark Conrad" wrote in message
...

I am seriousely contemplating buying a new 12.8 MP Canon.

Would appreciate advice from actual owners of that camera.

Contemplated usage will be mainly for producing offset lithography
phamplets and possibly larger 8 x 11 inch "slick" brochers.

My setup will be an Intel-based Mac using Photoshop (or other raw
editor) for editing the raw digital image from the Canon.

I have heard that the Canon has a fairly bad Moire effect, but I guess
all digital cameras in that price range are afflicted with the
Moire-effect problem, when offset lithography is used.
(colored bands in areas that should be plain, like flesh tones)

According to Hassleblad press releases, their newest 39 MP camera will
incorporate Moire-effect reduction techniques, however that camera will
be too costly for most users. I heard $43,000 (US).

I am essentially new to digital photography. The Canon 12.8-MP might
be my first digital camera of any kind.


Mark-