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So how good is 36 megapixels?



 
 
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  #41  
Old March 23rd 13, 12:26 AM posted to rec.photo.digital.slr-systems
Wolfgang Weisselberg
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Posts: 5,285
Default So how good is 36 megapixels?

Alan Browne wrote:
On 2013.03.20 22:16 , Doug McDonald wrote:
On 3/20/2013 6:34 PM, Alan Browne wrote:
The pictures show CONCLUSIVELY that the lens is fully adequate to
resolve adjacent pixels, and that the AA filer is NOT seriously

smearing
out the image enough to stop moire.


If the AA smeared it enough to remove the moiré that you captured in
your contrivation, then you would be just as happy with the detail of a
6 Mpix camera. Probably not even then.


I never said that I wanted no moire in this absolutely
utterly
worst case moire test. What makes you think I did? I LIKE the camera
the way it is. I just pointed out that if one tried to get it
to generate moire, it will do so.


Your "absurd" declaration did not, in any way, disprove what I said
about lens MTF softening as desired sampling (sensor density) goes up.


I thought the point was not that Doug diusputed that.

I thought the point was that Doug said that with his camera
and lens the point of lens MTF softening was not reached.

Further, what I said above wrt to AA filters was not meant to be what
you desire, just to illustrate the sort of heavy AA filter that would be
required to tame the moiré in your high school lab experiment.


(Another way of showing the irrelevancy of your examples if I have to
make that plain to you.)


The tactic of misunderstanding the point and ignoring
experiments and facts that collide with one's world view is
well used by fundamentalists and radicals everywhere.

Doug made it clear that under normal circumstances such moire
didn't happen.

Of course a lens with a crappy MTF will reduce moire. But my
trusty 24-105 f/4L zoom, not exactly the best L glass ever,
still generates some moire.


In summary, you retract what you said about my statement of lens mtf
acting as a softening filter where ever increasing sensor densities are
occurring.


Thought so. Next time just keep your hands off the keyboard and save
everyone some bandwidth.


Next time you take down your own strawmen, try not to gloat
so much.

-Wolfgang
  #42  
Old March 23rd 13, 12:58 PM posted to rec.photo.digital.slr-systems
David Taylor
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Posts: 1,068
Default So how good is 36 megapixels?

On 18/03/2013 14:15, Doug McDonald wrote:
[]
OK, I've posted the seriously moired pictures from a Canon 7D photographing
"Cupcake Wars" on FoodTV network on an LED TV. This used a Canon 50 mm
f/1.7 lens at
either f/4.5 or f/5.6, if you care, look at the EXIF. There are two scenes,
the version beginning in an underscore was "developed" from raw with
Digital Photo Professional
and is full frame. The ones beginning with A are developed with
Photoshop and are
cropped quite a bit. Be sure to view them blown up to at least 100% or
200%. The ones
done in Photoshop have very low sharpening done to them.

https://dl.dropbox.com/u/5310360/_MG_3388.JPG
https://dl.dropbox.com/u/5310360/_MG_3391.JPG
https://dl.dropbox.com/u/5310360/AMG_3388.jpg
https://dl.dropbox.com/u/5310360/AMG_3390.jpg

Note that the distance to the screen is very critical to get the full
disastrous moire effect, as is focus. I focused using the Live View.
The camera was on a tripod.

Amazing, isn't it! These pictures are truly unusable.

YET ... I've never photographed a real scene, even with that or my even
better
100mm f/2.8 Macro lens where I saw any problem at all.

People here have asked for moired pictures ... here they are!

Doug McDonald


Thanks for posting those, Doug. What immediately strikes me is how much
worse the "A" images are, converting a relatively gentle patterning on
the horizontal part of the arm into a series of nasty-looking pink
splodges! Around X:661 Y:1718 in AMG_3388. I therefore discount these
photoshopped images.

Considering the _MG_3388 image, yes, there is moir visible, but you
would expect some moir as the simple AA filters used in cameras are not
perfect, and are not the "brick-wall" filters used in audio.

Of course, the TV image should have an optical low-pass filter in front
to the display in any case, to ensure that only optical frequencies up
to those contained in the source signal are displayed. This is normally
achieved by viewing the image at a distance where you cannot see the
dots - the MTF of your eye and brain filter out the dots and lines.

Your later comment about the quality of the TV image itself - the
artefacts caused by compression for transmission - are quite valid. We
do not notice then partially because the image is moving and we don't
have time to concentrate of the errors, perhaps sometimes because we
expect a particular channel to have a low-bandwidth low-quality signal,
but perhaps mainly because we are interested in the content of the image
(and the accompanying sound) rather than in its technical quality.
Those who view testcards all day may have a different opinion!

Will there still be testcards anywhere on the UK broadcast network after
next Tuesday?
--
Cheers,
David
Web: http://www.satsignal.eu
  #43  
Old March 23rd 13, 05:08 PM posted to rec.photo.digital.slr-systems
Robert Coe
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Posts: 4,901
Default So how good is 36 megapixels?

On Sat, 23 Mar 2013 00:26:25 +0100, Wolfgang Weisselberg
wrote:
: Alan Browne wrote:
: On 2013.03.20 22:16 , Doug McDonald wrote:
: On 3/20/2013 6:34 PM, Alan Browne wrote:
: The pictures show CONCLUSIVELY that the lens is fully adequate to
: resolve adjacent pixels, and that the AA filer is NOT seriously
: smearing
: out the image enough to stop moire.
:
: If the AA smeared it enough to remove the moir that you captured in
: your contrivation, then you would be just as happy with the detail of a
: 6 Mpix camera. Probably not even then.
:
: I never said that I wanted no moire in this absolutely
: utterly
: worst case moire test. What makes you think I did? I LIKE the camera
: the way it is. I just pointed out that if one tried to get it
: to generate moire, it will do so.
:
: Your "absurd" declaration did not, in any way, disprove what I said
: about lens MTF softening as desired sampling (sensor density) goes up.
:
: I thought the point was not that Doug diusputed that.
:
: I thought the point was that Doug said that with his camera
: and lens the point of lens MTF softening was not reached.
:
: Further, what I said above wrt to AA filters was not meant to be what
: you desire, just to illustrate the sort of heavy AA filter that would be
: required to tame the moir in your high school lab experiment.
:
: (Another way of showing the irrelevancy of your examples if I have to
: make that plain to you.)
:
: The tactic of misunderstanding the point and ignoring
: experiments and facts that collide with one's world view is
: well used by fundamentalists and radicals everywhere.
:
: Doug made it clear that under normal circumstances such moire
: didn't happen.
:
: Of course a lens with a crappy MTF will reduce moire. But my
: trusty 24-105 f/4L zoom, not exactly the best L glass ever,
: still generates some moire.
:
: In summary, you retract what you said about my statement of lens mtf
: acting as a softening filter where ever increasing sensor densities are
: occurring.
:
: Thought so. Next time just keep your hands off the keyboard and save
: everyone some bandwidth.
:
: Next time you take down your own strawmen, try not to gloat
: so much.

Does anyone else appreciate the hilarity of this situation? Wolfgang
Weisselberg, of all people, trying to mediate a catfight of the sort he often
seems to relish as a participant! ;^)

Bob
  #44  
Old March 23rd 13, 11:06 PM posted to rec.photo.digital.slr-systems
Robert Coe
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Posts: 4,901
Default So how good is 36 megapixels?

On Sat, 23 Mar 2013 11:58:53 +0000, David Taylor
wrote:
: Will there still be testcards anywhere on the UK broadcast network
: after next Tuesday?

Why? What happens then?

Bob
  #45  
Old March 23rd 13, 11:15 PM posted to rec.photo.digital.slr-systems
Robert Coe
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Posts: 4,901
Default So how good is 36 megapixels?

On Mon, 18 Mar 2013 09:18:48 -0500, Doug McDonald
wrote:
: On 3/17/2013 9:25 PM, Doug McDonald wrote:
:
:
:
: I have the pictures. No, I', not so stupid as to not check for moire at
: 100% or 200% view. They are absolutely hilarious.
:
: One more comment: what is even more hilarious, if you look closely,
: are the truly horrendous, disastrous, amazingly ugly, MPEG artifacts
: introduced into the TV image by, presumably, Comcast. Look for the
: amazing bad blocking. Yes, this is visible watching TV.

I'd have pooh-poohed that; but earlier this afternoon I was watching CNN
(their hi-def channel via Comcast), and the motion was jerky and there was no
discernible connection between what the people in the scene were saying and
how their lips were moving. No matter how many "improvements" come to TV, I
guess "technical difficulties" will be with us always.

Bob
  #46  
Old March 24th 13, 12:50 AM posted to rec.photo.digital.slr-systems
Robert Coe
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Posts: 4,901
Default So how good is 36 megapixels?

On Fri, 22 Mar 2013 12:06:28 +1100, "Trevor" wrote:
:
: "Floyd L. Davidson" wrote in message
: ...
: "David J. Littleboy" wrote:
: "Wolfgang Weisselberg" wrote in message
: ...
: Trevor wrote:
:
: No, it also depends on how much improvement can be
: made in lens design, or
: it's just a number for the sake of a number. Sensor design is already
: outstripping lens capability,
:
: For mobile phone 41 MPix sensors, yes.
: For the tele end of superzoom 16 M Pix cameras, yes.
: For some kit lenses, especially outside their best
: performance, yes.
:
: Right, and for most available lenses once you get to 50mp and beyond
: in 35mm format. Which was my point.
: We should see a return in development and sales toward prime lenses,
: as zooms certainly won't cut it, and many of the primes will need
: improving to do so as well.

I doubt that we'll see that. The ongoing takeover of serious photography by
zooms has been largely unaffected by improvements in sensor resolution.
Instead, better sensors have been accompanied by better zooms. Though new,
better prime lenses are still being developed, they don't seem to be
reclaiming much market share. Primes have become a curiosity in most circles,
including this one, except for increasingly specialized purposes. There's
probably no going back.

Bob
  #47  
Old March 24th 13, 02:13 AM posted to rec.photo.digital.slr-systems
David J. Littleboy
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Posts: 2,618
Default So how good is 36 megapixels?

"Robert Coe" wrote:
On Fri, 22 Mar 2013 12:06:28 +1100, "Trevor" wrote:
:
: Right, and for most available lenses once you get to 50mp and beyond
: in 35mm format. Which was my point.
: We should see a return in development and sales toward prime lenses,
: as zooms certainly won't cut it, and many of the primes will need
: improving to do so as well.

I doubt that we'll see that. The ongoing takeover of serious photography by
zooms has been largely unaffected by improvements in sensor resolution.
Instead, better sensors have been accompanied by better zooms. Though new,
better prime lenses are still being developed, they don't seem to be
reclaiming much market share. Primes have become a curiosity in most
circles,
including this one, except for increasingly specialized purposes. There's
probably no going back.


I found that the lenses that were somewhat iffy (Canon 17-40, original 24
TSE) on the 12MP 5D were absolute dogs on the 21MP 5DII, and some lenses
that were OK (Tamron 28-75/2.8) became iffy.

So my 5DII kit was the Zeiss 21/2.8, Voightlander 40/2.0, and Stigma 70/2.8
macro. All of these (and the Canon 24 TSE II) cough up corner-to-corner
pixel sharp images. Every time, all the time. (OK, at sensible f stops, and
my tripod is heavier than yours.)

Now, it's the same story with the Canon 24-70/2.8 II.

I find it hard to imagine that any of these will have trouble on 36MP (7360
x 4912); although it may require using a narrower range of f stops. These
lenses are better on the 5DII than the old lenses were on the 5D.

Sure, there will be some diminishing returns: it won't be the whole 30%
improvement. But there's also an _increasing returns_ factor from larger
prints: People who come in for a closer look won't get as close to a 20x30
print as they do to an 11x14.

So if you like 12x18 prints (300 ppi) from the 5DII, you'll love 16x24
prints (also 300 ppi) from the D800. Ditto for 16x24 5DII (230 ppi) prints
vs. 20x30 D800 (240 ppi).

Of course, who knows if Canon will ever get off their duffs and cough up an
affordable 36MP camera...

--
David J. Littleboy
Tokyo, Japan

  #48  
Old March 24th 13, 06:33 PM posted to rec.photo.digital.slr-systems
David Taylor
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Posts: 1,068
Default So how good is 36 megapixels?

On 23/03/2013 22:06, Robert Coe wrote:
On Sat, 23 Mar 2013 11:58:53 +0000, David Taylor
wrote:
: Will there still be testcards anywhere on the UK broadcast network
: after next Tuesday?

Why? What happens then?

Bob


BBC-HD (which does broadcast testcards) is replaced by BBC2-HD (which
does not).
--
Cheers,
David
Web: http://www.satsignal.eu
  #49  
Old March 25th 13, 10:24 AM posted to rec.photo.digital.slr-systems
Trevor[_2_]
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Posts: 874
Default So how good is 36 megapixels?


"Robert Coe" wrote in message
...
No matter how many "improvements" come to TV, I
guess "technical difficulties" will be with us always.


Or because of it. Big delays when I saw "the Hobbit" at the cinema, as they
struggled to get things right.
3D-4k was just something new to go wrong as far as they were concerned.

Trevor.


  #50  
Old March 25th 13, 10:29 AM posted to rec.photo.digital.slr-systems
Trevor[_2_]
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Posts: 874
Default So how good is 36 megapixels?


"Robert Coe" wrote in message
news
: Right, and for most available lenses once you get to 50mp and beyond
: in 35mm format. Which was my point.
: We should see a return in development and sales toward prime lenses,
: as zooms certainly won't cut it, and many of the primes will need
: improving to do so as well.

I doubt that we'll see that. The ongoing takeover of serious photography
by
zooms has been largely unaffected by improvements in sensor resolution.
Instead, better sensors have been accompanied by better zooms.


Better yes, good enough for 50 mp true resolution, NO.


Though new,
better prime lenses are still being developed, they don't seem to be
reclaiming much market share. Primes have become a curiosity in most
circles,
including this one, except for increasingly specialized purposes. There's
probably no going back.


Agreed, and as I already said, people won't care because the 50mp is for
boasting rights, even if the real data resolution with lens is half that.
Just as well hard drives are cheap now though! :-)

Trevor.


 




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