Aliasing and moire problem on d610

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Nikola

New member
Hi to all of you guys,
I'm new here so as first I wanted to say hello :D

As I said on the heading: I have a aliasing and moire problem on my d610! As first I notice it on the videos but I guess these is how it is, and the real problems actually begin when I notice the same issues when shooting stills!
I'm sending some samples of what I'm talking about so you can see how does it look like.

Does anyone have the same problem like me, or is it something wrong with my camera?

Thanks, and best...
Nikola
 

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Blade Canyon

Senior Member
I see moire in the first pic and aliasing in the third pic, but what's in the middle pic? I see nothing wrong there.

Honestly, there's probably nothing wrong with your camera. This is just a fact of life with digital sensors. Do you see the moire if you look at the pic at 100%?
 
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Nikola

New member
Sorry for the late reply...

Thanks both of you!

Yes, I can see the moire all the way; It's happening two often in similar situations!
Did you had a moire problem with your camera?

Best, Nikola
 
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WayneF

Senior Member
Moire in the sensor is basically when the detail in the image (the size of the closely spaced stripes) are finer detail than the pixel spacing of the sensor can resolve. Hence alaising, false detail that we call moire.

Size depends on distance, stripes appear larger when up closer.

Anti-aliasing filters on sensors just blur the image a little bit, not enough to much matter, but just a bit so to eliminate finer detail than the sensor cannot resolve, hence no alaising. Today some 24 megapixel cameras are omitting the AA filter, being assumed enough resolution, sufficient to not be a problem ... very often. Not fail safe.

How does the original size image look at 100% size? See moire there?

Resampling high resolution images to be smaller can in some cases cause moire, containing detail finer than the resampling of the smaller image can show. In such cases, very slightly blurring the image (about the slightest amount) before resampling can prevent the moire. That blurring does not hurt anything, an image 1/8 the size only contains 1/8 the detail anyway.

Also showing the image on the LCD monitor can in a few cases show moire, due to the matrix spacing of the screen. As we zoom to change size, we might sometimes go through a zone that shows moire (a few images might).


Probably the worst cases are when scanning magazine images (typically 150 dot per inch halftone images) with scan resolutions not exceeding the 150 dpi. It really needs 2x or 4x sampling (300 dpi or 600 dpi) to prevent the moire then.
 
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Nikola

New member
Hi WayneF,
Thanks for your replay; I did not try blurring the image...; but I will!
So you think it is normal? Did you have any of these problem with your d800?

Best, Nikola
 
W

WayneF

Senior Member
Nikola said:
Hi WayneF,
Thanks for your replay; I did not try blurring the image...; but I will!
So you think it is normal? Did you have any of these problem with your d800?

Best, Nikola
Click to expand...

Not "normal", but I think aliasing is always possible, in rare events. We do sometimes see it in men's coats in TV news (notice that the anchor guy will never wear a patterned coat). It is just something that happens in digital images sometimes, when the subject detail is finer than the camera sensor can resolve.

No, I have not had much trouble with the D800 (it has 36 megapixels, a little higher resolution sampling). A few cameras have no anti-alaising filter now (D810 36 mp FX or D7200 24 mp DX, both a little higher resolution sampling than 24mp FX). It was more problem when we had 12 megapixels or less. The D610 has a filter, but I have heard it's a little "weaker anti-aliasing filter, but I know no details.

I cannot say that I see the aliasing in your first two pictures.

It can also happen in the computer, so I still wonder if you can see this in the original image from the camera, when viewed at 100% size (zoomed to 100%).

If you don't (which I think it is very possible that you don't), then it is not at all an issue with the camera sampling, but instead due to later sampling. If concerned, that's the first thing to check.
 
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Nikola

New member
WayneF said:
Not "normal", but I think aliasing is always possible, in rare events. We do sometimes see it in men's coats in TV news (notice that the anchor guy will never wear a patterned coat). It is just something that happens in digital images sometimes, when the subject detail is finer than the camera sensor can resolve.

No, I have not had much trouble with the D800 (it has 36 megapixels, a little higher resolution sampling). A few cameras have no anti-alaising filter now (D810 36 mp FX or D7200 24 mp DX, both a little higher resolution sampling than 24mp FX). It was more problem when we had 12 megapixels or less. The D610 has a filter, but I have heard it's a little "weaker anti-aliasing filter, but I know no details.

I cannot say that I see the aliasing in your first two pictures.

It can also happen in the computer, so I still wonder if you can see this in the original image from the camera, when viewed at 100% size (zoomed to 100%).

If you don't (which I think it is very possible that you don't), then it is not at all an issue with the camera sampling, but instead due to later sampling. If concerned, that's the first thing to check.
Click to expand...

I previously had D200, it was really a DX beast of a camera - never had these kind of problems (slightly more than 10mp); it actually looks like I didn't know about aliasing and moire before - not from today's point of view, anyway!

I wanted to check with my friend before answer you...; how do you don't see aliasing?... I'm posting first photo in full resolution so you can check again. About 100% zoom...; it's still there! check for you self.
_DSC4362.jpg

Hm, I just realized...: could it be of the importance the fact that I use DX crop mode on my D610 (a have a 35 DX lens mounted on my camera)? It's in a camera crop, so the 24mp sensor stays the same but I wanted to mention.

Hey, and thank a lot for wanted to bother with my problem; Best, Nikola
 
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WayneF

Senior Member
Yes, it does not show up well, but I do see it in the blue shirt. But that is not near the 100% size that I meant. That might be 100% of the processed and resampled small final copy, but I am speaking of the original image size from the camera. I fear what you might mean is that if you overwrote the original image file with the processed copy, the small copy might be all you have left now? (in which case, there is no answer left to find... maybe next time?)

The D610 image is much larger than your computer monitor screen. D610 FX is 6016x4016 pixels, and DX is 3936x2624 pixels. I don't know your monitor screen size, but almost all are not larger than 1920x1080 pixels, if that. So 100% is much larger than our monitor screen. We can only see a small part of the image then (at 100%).

In your photo editor, when showing the original image from the camera (NOT a resampled smaller copy of it), just Zoom your editor view to 100% Actual size. I have not stopped to compute numbers, but that will be so big that about all you can see is maybe like the mans arm and elbow (from the center) Then scroll over to see the shirt, and decide if you see the moire then (at 100% in the original camera image).

If you do, it is aliasing in the image, and the camera sampling did it. If you don't, it's not in the image, and subsequent resampling did it. The slight blurring technique works in the second case, and probably not in the first case (although resampling small can help hide it).

The D200 at 10mp is about the same sampling susceptibility to moire as the D610 (but their anti-aliasing filters may be different strength). DX in the D610 is 3936x2624 pixels, or also about 10 mp. But that DX size is still at least twice larger than your computer monitor screen, and possibly even larger than that in your editors window. Look at it that large. The editor will specifically call that zoomed view as 100% size, or Actual size.
 
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Nikola

New member
WayneF said:
Yes, it does not show up well, but I do see it in the blue shirt. But that is not near the 100% size that I meant. That might be 100% of the processed and resampled small final copy, but I am speaking of the original image size from the camera. I fear what you might mean is that if you overwrote the original image file with the processed copy, the small copy might be all you have left now? (in which case, there is no answer left to find... maybe next time?)

The D610 image is much larger than your computer monitor screen. D610 FX is 6016x4016 pixels, and DX is 3936x2624 pixels. I don't know your monitor screen size, but almost all are not larger than 1920x1080 pixels, if that. So 100% is much larger than our monitor screen. We can only see a small part of the image then (at 100%).

In your photo editor, when showing the original image from the camera (NOT a resampled smaller copy of it), just Zoom your editor view to 100% Actual size. I have not stopped to compute numbers, but that will be so big that about all you can see is maybe like the mans arm and elbow (from the center) Then scroll over to see the shirt, and decide if you see the moire then (at 100% in the original camera image).

If you do, it is aliasing in the image, and the camera sampling did it. If you don't, it's not in the image, and subsequent resampling did it. The slight blurring technique works in the second case, and probably not in the first case (although resampling small can help hide it).

The D200 at 10mp is about the same sampling susceptibility to moire as the D610 (but their anti-aliasing filters may be different strength). DX in the D610 is 3936x2624 pixels, or also about 10 mp. But that DX size is still at least twice larger than your computer monitor screen, and possibly even larger than that in your editors window. Look at it that large. The editor will specifically call that zoomed view as 100% size, or Actual size.
Click to expand...

Hi WayneF,

I upload the file with full resolution but I don't know why it didn't show like that?! Never the less, I know what 100% is but it still have the same issue
(I Zoom my editor view to 100% Actual size at the first time I look in to it)!
Thanks a lot...; I really am grateful for your replies - but I guess it doesn't look like having in mind my late replies : )

Thanks again; Nikola
 
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WayneF

Senior Member
Nikola said:
Hi WayneF,

I upload the file with full resolution but I don't know why it didn't show like that?!
Click to expand...

I assume the forum resamples uploaded large images smaller, to not save it larger than 1024 pixels? Cannot zoom it any larger here now. The image still shows well enough, but the moire is harder to see than at 100%. :)
 
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Nikola

New member
Yes, I suppose :)
So what do you think: is that moire shit something I have to live with, or should I check with Nikon authorized service?
 
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WayneF

Senior Member
I doubt there is anything Nikon can do to fix moire, it is caused by subject detail resolution exceeding what the camera sensor can resolve. With a good lens in good conditions, that is not impossible in some cases (but maybe not a common scene occurrence). The anti-aliasing filter is there to help prevent moire (to blur away finer detail than the sensor can resolve). The D610 is said to implement a weaker filter than before, but that does not describe details.

This is the fourth time I have asked, but I am not aware that you have ever answered "Can you see the moire when viewing the original camera image at 100% size?"

If you cannot, the camera sensor did not do it, subsequent resampling did it, either resampling it smaller, or the video screen viewing it smaller. If you can, then it sounds like one of those things that just happens sometimes (but I'm not sure these images really are special cases?)

I am guessing that you may not be able to see these moire cases in the camera original images at 100%. Possibly you may not still have the original camera image if you resampled JPG and overwrote it.
 
N

Nikola

New member
WayneF said:
This is the fourth time I have asked, but I am not aware that you have ever answered "Can you see the moire when viewing the original camera image at 100% size?"
Click to expand...

Yes; as I said:"Never the less, I know what 100% is but it still have the same issue (I Zoom my editor view to 100% Actual size at the first time I look in to it)!" - I did it with the RAW file, which I don't have any more, but it was there!



​
 
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WayneF

Senior Member
OK, sorry, my mistake, I didn't understand. So then it does sound like regular sensor moire. You can contact Nikon, but there is nothing they can do.

How often do you see this happen? Regularly, or was this the first time?

Previously, Nikon designed the D800E camera without any anti-aliasing filter at all. It is 36 megapixels, which is greater resolution and so less susceptible to moire, so moire was considered not a likely problem. A few users did report they sometimes see it, but it seems not to trouble most users.

Here is a Nikon article about it:

Moire and False Color | The Role of the OLPF in D-SLRs from Nikon

It offers a tip or two.
 
N

Nikola

New member
No prob. ...

WayneF said:
How often do you see this happen? Regularly, or was this the first time?
Click to expand...

From time to time. Not very often, but it can be bad in case I have to shoot some one who is wearing a clothes with "just the right" pattern! : )


Thanks a lot again...


Best, Nikola
 
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