Today I tried to take a picture of the strings of a grand piano,
from the back end, and got a significant moire pattern in the area
where the bass strings lie above the treble strings, but are strung
in different directions. This criss-cross area looked pretty bad.
Is there anything I can do to reduce or eliminate this effect? Any
camera setting that I could select?
Would a better camera do better in this situation, or is it just
physics? Does the A590 not have any low-pass filter to reduce this
aliasing problem?
On Wed, 04 Nov 2009 19:09:52 -0600, Peabody <waybackNO784SPAM44@yahoo.com>
wrote:
>Today I tried to take a picture of the strings of a grand piano,
>from the back end, and got a significant moire pattern in the area
>where the bass strings lie above the treble strings, but are strung
>in different directions. This criss-cross area looked pretty bad.
>
>Is there anything I can do to reduce or eliminate this effect? Any
>camera setting that I could select?
>
>Would a better camera do better in this situation, or is it just
>physics? Does the A590 not have any low-pass filter to reduce this
>aliasing problem?
Turn down the in-camera sharpening to the lowest level. Might help to turn
down contrast to lowest level too. You will also avoid that by simply
changing the angle of your sensor to the angle of the moire'-causing
subject. You can rotate later in post-processing (use Lanczos-8 resampling
algorithm if available for rotations and resizing).
Do those sharpening and contrast phases in post processing. I never let any
camera handle those to any degree if it allows for it.
Peabody <waybackNO784SPAM44@yahoo.com> wrote:
> Today I tried to take a picture of the strings of a grand piano,
> from the back end, and got a significant moire pattern in the area
> where the bass strings lie above the treble strings, but are strung
> in different directions. This criss-cross area looked pretty bad.
> Is there anything I can do to reduce or eliminate this effect? Any
> camera setting that I could select?
> Would a better camera do better in this situation, or is it just
> physics? Does the A590 not have any low-pass filter to reduce this
> aliasing problem?
You will always be able to get moire effects when viewing images at
less than the meximum size. The camera's anti-aliasing filter only
applies to its maximum resolution.
Do you still see this effect on the maximum full size image?
> You will always be able to get moire effects when
> viewing images at less than the meximum size. The
> camera's anti-aliasing filter only applies to its
> maximum resolution.
> Do you still see this effect on the maximum full size
> image?
Well, using the full 8MP, and viewing the pic on my biggest
monitor, the moire is almost completely removed. Actually,
the problem may have been more in the display medium than in
the picture itself. The smaller the display, the more
the moire shows up. Review on the camera itself is
particularly bad.
In article <wBpIm.349$Wf2.15@newsfe23.iad>, Peabody says...
> Today I tried to take a picture of the strings of a grand piano,
> from the back end, and got a significant moire pattern in the area
> where the bass strings lie above the treble strings, but are strung
> in different directions. This criss-cross area looked pretty bad.
>
> Is there anything I can do to reduce or eliminate this effect? Any
> camera setting that I could select?
>
> Would a better camera do better in this situation, or is it just
> physics? Does the A590 not have any low-pass filter to reduce this
> aliasing problem?
Canon uses too weak antialiasing filters in their cameras, to maximise
the perceived resolution in the images. Other manufacturers use stronger
AA filters to avoid this problem.
--
"Peabody" <waybackNO784SPAM44@yahoo.com> wrote in message
news:mTsIm.3249$gg6.1087@newsfe25.iad...
[]
> Well, using the full 8MP, and viewing the pic on my biggest
> monitor, the moire is almost completely removed. Actually,
> the problem may have been more in the display medium than in
> the picture itself. The smaller the display, the more
> the moire shows up. Review on the camera itself is
> particularly bad.
>
> I hope that means it won't show up in prints.
>
> Thanks for your help.
Peabody,
When displaying at less than full image resolution you really need
software which resamples the image correctly rather than using some
nearest neighbour pixel selection (exaggerating moiré). Make sure that
resampling (even upscaling) is properly carried out when you print.
Alfred Molon wrote:
> In article <wBpIm.349$Wf2.15@newsfe23.iad>, Peabody says...
>> Today I tried to take a picture of the strings of a grand piano,
>> from the back end, and got a significant moire pattern in the area
>> where the bass strings lie above the treble strings, but are strung
>> in different directions. This criss-cross area looked pretty bad.
>>
>> Is there anything I can do to reduce or eliminate this effect? Any
>> camera setting that I could select?
>>
>> Would a better camera do better in this situation, or is it just
>> physics? Does the A590 not have any low-pass filter to reduce this
>> aliasing problem?
>
> Canon uses too weak antialiasing filters in their cameras, to maximise
> the perceived resolution in the images. Other manufacturers use stronger
> AA filters to avoid this problem.
I don't think that's true for the A590 - my 8Mp
A590 is massively less sharp than my 8mp A630.
Info Man wrote:
> On Wed, 04 Nov 2009 19:09:52 -0600, Peabody <waybackNO784SPAM44@yahoo.com>
> wrote:
>
>> Today I tried to take a picture of the strings of a grand piano,
>>from the back end, and got a significant moire pattern in the area
>> where the bass strings lie above the treble strings, but are strung
>> in different directions. This criss-cross area looked pretty bad.
>>
>> Is there anything I can do to reduce or eliminate this effect? Any
>> camera setting that I could select?
>>
>> Would a better camera do better in this situation, or is it just
>> physics? Does the A590 not have any low-pass filter to reduce this
>> aliasing problem?
>
> Turn down the in-camera sharpening to the lowest level. Might help to turn
> down contrast to lowest level too.
The A590 doesn't have a contrast adjust. Indeed, I'm not aware of a camera
that does, or what it would (usefully) do.
"bugbear" <bugbear@trim_papermule.co.uk_trim> wrote in message
news:n7qdnQNnjerZBW_XnZ2dnUVZ7o5i4p2d@brightview.c o.uk...
[]
> The A590 doesn't have a contrast adjust. Indeed, I'm not aware of a
> camera
> that does, or what it would (usefully) do.
>
> Could you help out?
>
> BugBear
David J Taylor wrote:
>
> "bugbear" <bugbear@trim_papermule.co.uk_trim> wrote in message
> news:n7qdnQNnjerZBW_XnZ2dnUVZ7o5i4p2d@brightview.c o.uk...
> []
>> The A590 doesn't have a contrast adjust. Indeed, I'm not aware of a
>> camera
>> that does, or what it would (usefully) do.
>>
>> Could you help out?
>>
>> BugBear
>
> Just two examples:
>
> Nikon D5000 - compare Vivid with Natural:
> http://www.dpreview.com/reviews/nikond5000/page18.asp
>
> Nikon D700 compare Vivid with Neutral:
> http://www.dpreview.com/reviews/NikonD700/page20.asp
>
> I think that other non-DSLR cameras I've had provide similar options
> under a variety of names.
Ah - "those" - thank you.
The A590 does indeed have those, but I've never used them.
I assumed (wrongly) you meant something more
like auto-adjust levels, or contrast-stretch
as found in DeskTop packages.
Moire in Canon A590 
Linear Mode
