Strange OOF banding with 200-500 + d500.

Started Jul 4, 2017 | Discussions
SMC Natural History
SMC Natural History Forum Member • Posts: 52
Strange OOF banding with 200-500 + d500.
1

Hi All,

I've been using this combo fairly extensively with good results. Recently I noticed strange banding in the out of focus (bokeh) areas in a shot near close focus distance. I think the EXIF is scrubbed from this image but it was shot wide open at 1/500th from about 8 feet @ 500 mm. Light was good (ISO below 500). I've highlighted the strange banding in the accompanying photo. I thought it might be grass or something at first but you can see it extends all the way down and across the birds leg in the right hand arrows.

I'm curious what you think. Is it just an artifact of conditions (close focus, background relatively close to subject, max aperture only 5.6, max zoom)???

Thanks in advance for your contributions (trolls need not apply).

Cheers,

Gabriel

Nikon 200-500mm F5.6E ED VR Nikon D500
If you believe there are incorrect tags, please send us this post using our feedback form.
Marianne Oelund Veteran Member • Posts: 7,788
It's called doubling and it's normal
9

SMC Natural History wrote:

Hi All,

I've been using this combo fairly extensively with good results. Recently I noticed strange banding in the out of focus (bokeh) areas in a shot near close focus distance. I think the EXIF is scrubbed from this image but it was shot wide open at 1/500th from about 8 feet @ 500 mm. Light was good (ISO below 500). I've highlighted the strange banding in the accompanying photo. I thought it might be grass or something at first but you can see it extends all the way down and across the birds leg in the right hand arrows.

I'm curious what you think. Is it just an artifact of conditions (close focus, background relatively close to subject, max aperture only 5.6, max zoom)???

Unless the lens is intentionally designed with some under-correction of SA (spherical aberration), high-contrast lines in backgrounds will provoke this kind of detail.  It is because the edges of the blur circles are abrupt, instead of diffuse.

It is difficult to maintain a pleasing background blur across the focal range of zoom lenses, and this aspect of design usually has a low priority for telephoto zooms.

-- hide signature --

Source credit: Prov 2:6
- Marianne

Per Baekgaard Senior Member • Posts: 1,288
Re: Strange OOF banding with 200-500 + d500.

In addition to what Marianne said:

Was this shot on a warm day, with lot's of air turbulence and specular reflections? My own experience with a few of these long zooms is that I more often see this when it's warm and sunny.

Also, do you have VR engaged? It may still be a debated issue, but I also anecdotally see more of these weird oof shapes with VR than when shooting from a tripod -- although it would also be related to some other factors than VR that just happens to be coincidental to me using a tripod

- Per.

 Per Baekgaard's gear list:Per Baekgaard's gear list
Nikon D800 Nikon D500 Nikon AF-S Nikkor 70-200mm f/2.8G ED VR Nikon AF-S Nikkor 14-24mm f/2.8G ED Nikon AF-S Nikkor 24-70mm f/2.8G ED +17 more
scokill
scokill Veteran Member • Posts: 6,531
Re: It's called doubling and it's normal

Marianne Oelund wrote:

SMC Natural History wrote:

Hi All,

I've been using this combo fairly extensively with good results. Recently I noticed strange banding in the out of focus (bokeh) areas in a shot near close focus distance. I think the EXIF is scrubbed from this image but it was shot wide open at 1/500th from about 8 feet @ 500 mm. Light was good (ISO below 500). I've highlighted the strange banding in the accompanying photo. I thought it might be grass or something at first but you can see it extends all the way down and across the birds leg in the right hand arrows.

I'm curious what you think. Is it just an artifact of conditions (close focus, background relatively close to subject, max aperture only 5.6, max zoom)???

Unless the lens is intentionally designed with some under-correction of SA (spherical aberration), high-contrast lines in backgrounds will provoke this kind of detail. It is because the edges of the blur circles are abrupt, instead of diffuse.

It is difficult to maintain a pleasing background blur across the focal range of zoom lenses, and this aspect of design usually has a low priority for telephoto zooms.

Agreed.  If the background was further away from the subject I don't think you would have this rendering.  Also posting a .3MP photo makes it difficult to see exactly what is going on.

 scokill's gear list:scokill's gear list
Nikon D4 Nikon AF-S Nikkor 24-70mm f/2.8G ED Nikon AF-S 70-200mm F2.8E FL ED VR
Leonard Shepherd
Leonard Shepherd Forum Pro • Posts: 22,216
Re: It's called doubling and it's normal
1

Marianne Oelund wrote:

high-contrast lines in backgrounds will provoke this kind of detail. It is because the edges of the blur circles are abrupt, instead of diffuse.

Thanks for the explanation.

It is an issue I encounter occasionally, including with the 200 macro D.

Usually changing the shooting angle (not always possible) avoids the problem.

-- hide signature --

Leonard Shepherd
Some say if some of your photos are not good the camera you use is only a recording device.

 Leonard Shepherd's gear list:Leonard Shepherd's gear list
Nikon D500 Nikon D850 Nikon Z7 Nikon AF-S Nikkor 14-24mm f/2.8G ED Nikon AF-S Micro-Nikkor 60mm F2.8G ED +27 more
Entropius Veteran Member • Posts: 4,392
Re: Strange OOF banding with 200-500 + d500.
2

Per Baekgaard wrote:

In addition to what Marianne said:

Was this shot on a warm day, with lot's of air turbulence and specular reflections? My own experience with a few of these long zooms is that I more often see this when it's warm and sunny.

This is what I suspect as well. Refraction of light through air can cause all sorts of weirdness, and I've seen this effect -- unexpected structure in bokeh -- quite a bit in Arizona. This is much worse when you're shooting over sunlit (= warm) rocks, and the air over them has a turbulent mix of warm and cold air.

 Entropius's gear list:Entropius's gear list
Nikon D500 Sigma 18-35mm F1.8 DC HSM Art Nikkor AF-S 300mm f/4E PF ED VR
calson Forum Pro • Posts: 10,575
Re: Strange OOF banding with 200-500 + d500.

It looks like the moire effect which is more likely to present itself with the AA filters not being used in cameras like the D500.

As mentioned it is distance and direction specific so at a different distance or zoom setting it is not likely to be present. When I do get moire in a shot it is usually in at most two frames out of a sequence and it has been incredibly rare and in my own experience, the result of subjects with repeating patterns (stripped shirts and ties and lace).

I would also want to verify that this is present in the file when processed with Nikon Capture NX as I have had more problems with "banding" when using Adobe ACR to convert RAW files.

-- hide signature --

"The people can always be brought to the bidding of the leaders…tell them they are being attacked, and denounce the peacemakers for lack of patriotism and exposing the country to danger."

- Hermann Goring

 calson's gear list:calson's gear list
Nikon D5 Nikon D850
Entropius Veteran Member • Posts: 4,392
Re: Strange OOF banding with 200-500 + d500.

This isn't moire.

Moire happens because of the ambiguity between high-frequency luminance detail close to the Nyquist cutoff and low-frequency chroma information.

You only get ultra-high-frequency luminance detail in the plane of focus with a sharp lens. This artifacting is happening in the bokeh, where there is no high-frequency detail for the demosaic algorithm to mistake for color information.

Most likely, this is distortion caused by refraction through a region of air that has turbulent mixing between hot air and cold air. I often see odd texture like this in the bokeh of shots taken over sunlit rocks in Arizona.

 Entropius's gear list:Entropius's gear list
Nikon D500 Sigma 18-35mm F1.8 DC HSM Art Nikkor AF-S 300mm f/4E PF ED VR
evan47
evan47 Senior Member • Posts: 1,636
Re: Strange OOF banding with 200-500 + d500.

I noticed this kind of banding in the photos of one of my flickr followers. he was using a d7200 and tamron 150-600 g2 so I do not think it is exclusive to the d500/200-500 combo.

The shots did appear to be heavily cropped.

 evan47's gear list:evan47's gear list
Sony RX10 IV
Entropius Veteran Member • Posts: 4,392
Re: Strange OOF banding with 200-500 + d500.

evan47 wrote:

I noticed this kind of banding in the photos of one of my flickr followers. he was using a d7200 and tamron 150-600 g2 so I do not think it is exclusive to the d500/200-500 combo.

The shots did appear to be heavily cropped.

No, it's certainly not. I've seen it on superzooms, not-micro Four Thirds cameras with a cheapie 70-300, and several different Nikon and Canon lenses and cameras.

It's an optical effect happening out in the air, and thus isn't affected by cameras and lenses.

 Entropius's gear list:Entropius's gear list
Nikon D500 Sigma 18-35mm F1.8 DC HSM Art Nikkor AF-S 300mm f/4E PF ED VR
Ryan Glick New Member • Posts: 2
Re: Strange OOF banding with 200-500 + d500.

So I have the same issue how can you get around it, since most people want to use it at the 500mm mark keeping the background out of focus and wide open at 5.6. This was shot with a D850 at iso320 f5.6

Leonard Shepherd
Leonard Shepherd Forum Pro • Posts: 22,216
Re: Strange OOF banding with 200-500 + d500.

Ryan Glick wrote:

So I have the same issue how can you get around it, since most people want to use it at the 500mm mark keeping the background out of focus and wide open at 5.6. This was shot with a D850 at iso320 f5.6

Thanks for posting the image - posting an image often helps a lot.

I presume you are referring to the vertical lines, some not quite vertical, toward the top of the picture in the out of focus zone.

If I am right these seems to be a combination of strong highlight side lighting on the relatively tall vegetation combined with less than perfect lens bokeh.

Whether you would have got the "distraction" (it is a distraction) with "pro price" lenses like the 200-400 or a 400 or 500 prime at the same aperture is impossible to know, but problem either not or less so.

In theory you should not get this type of distraction in overcast lighting.

For the best shot in the sequence (assuming the stork kept reasonable still and you were able to get several) the problem can be reduced by "medium level" post processing

-- hide signature --

Leonard Shepherd
In lots of ways good photography is much more about how equipment is used rather than the equipment being used.

 Leonard Shepherd's gear list:Leonard Shepherd's gear list
Nikon D500 Nikon D850 Nikon Z7 Nikon AF-S Nikkor 14-24mm f/2.8G ED Nikon AF-S Micro-Nikkor 60mm F2.8G ED +27 more
Ryan Glick New Member • Posts: 2
Re: Strange OOF banding with 200-500 + d500.

Thanks for the info. I’m now considering buying a 200-400 f4 instead of the 200-500 but not sure if I will miss the extra 100mm. I could use it on my D500 but I really like my D850.

oh by the way just to let you know that the bird is a Great Blue Heron, I’m not being facetious  Just letting you know.

breivogel Senior Member • Posts: 2,403
Re: Strange OOF banding with 200-500 + d500.

The artifacts you see are pretty common with the 200-500.  Here is an example (another heron).  Linear features, like grass blades are the worst.  Most noticeable when they are just a bit out of focus.   I don't know if a prime  lens would be better.  I would advise renting one of the exotic  telephotos prior to purchase, though.

 breivogel's gear list:breivogel's gear list
Panasonic Lumix DMC-LX7 Sony Cyber-shot DSC-RX10 Sony RX100 III Sony RX100 IV Olympus TG-5 +19 more
DAVID MANZE Veteran Member • Posts: 6,390
It's "interference patterns"! Nisan bokeh!
2

This "interference" pattern" which it is,....... is caused by the splitting of out of focus detailed transition backgrounds, such as grass/ bushes/ scrub etc. It's called Nisan bokeh! (excuse if I miss-spelled the word)

A simple example is of a a dry blade of grass behind the point of focus, which becomes split into two hard outer edges with a softer focus between, these harder edges being far more visible than the soft inner part.

In denser backgrounds these hard outer edges mix with all the other hard outer edges of grass which there are many........and form "interference patterns" (the adding and subtracting of amassed edges), these are seen in the focus transition area behind the subject.

Telephoto lenses suffer the most in transition areas with Nisan bokeh, further behind the subject things soften beyond any bokeh splitting and become smooth, to the point where this effect disappears completely and the we are left with soft gentle back- grounds.

I indeed spent much time pondering at this "not so pleasant effect" which is often discussed on forums and I heard explanations of "uneven lens grinding and the like".

But it isn't....... it's simply interference patterns developing from Nisan bokeh in the OOF transition area!

Dave's clichés

 DAVID MANZE's gear list:DAVID MANZE's gear list
Nikon D750 Nikon D500 Nikon AF-S DX Nikkor 16-85mm f/3.5-5.6G ED VR Nikon AF Nikkor 24mm f/2.8D Nikon AF Nikkor 28mm f/2.8D +17 more
PHXAZCRAIG
PHXAZCRAIG Forum Pro • Posts: 17,962
Here's an example?

Normally I have excellent bokeh from the 200-500, but certain backgrounds at certain distances ...   Have a look at this image full-size.

-- hide signature --

Phoenix Arizona Craig
www.cjcphoto.net

 PHXAZCRAIG's gear list:PHXAZCRAIG's gear list
Nikon D80 Nikon D200 Nikon D300 Nikon D700 Nikon 1 V1 +37 more
DAVID MANZE Veteran Member • Posts: 6,390
Re: Here's an example?

PHXAZCRAIG wrote:

Normally I have excellent bokeh from the 200-500, but certain backgrounds at certain distances ... Have a look at this image full-size.

I'm not sure if you are happy or not?........

........but the stones don't show up the effect as much as grass/straw would do (less edges and more surface).....however the splitting of the edges is clear to see.......

.....but it still looks a little harsh though not so bad..........in situations like that I reduce sharpness in the background with the adjustment brush (ACR)......smooths it over nicely!

-- hide signature --

Dave's clichés

 DAVID MANZE's gear list:DAVID MANZE's gear list
Nikon D750 Nikon D500 Nikon AF-S DX Nikkor 16-85mm f/3.5-5.6G ED VR Nikon AF Nikkor 24mm f/2.8D Nikon AF Nikkor 28mm f/2.8D +17 more
beatboxa Veteran Member • Posts: 7,962
Apodization filters (DIY?)

Ryan Glick wrote:

how can you get around it

One potential remedy would be to create a front filter that slowly diffuses from clear in the middle to darker on the outside, along the lines of this:

These are called "apodization" filters. Some portrait lenses have these built into the internal elements. For example, Fuji has 2 different versions of its 56mm F/1.2 portrait lens: (Right = embedded APD filter)

One problem with this approach will be in (potentially) significantly worse autofocus performance. This approach darkens the outer parts of the lens, which is where the samples for phase-detect autofocus are taken--if they're too dark too far center, AF will fail completely. Example: the Fuji APD lens doesn't support PDAF.

In addition, the image will be darker--this will give less priority to the light samples from the outside of the lens by reducing its intensity.

These filters don't have to be exact or perfectly smooth. You can try experimenting by getting a cheap, clear/UV filter, and trying to shade it yourself with markers or a series of layered ND filters. The speed and distance from center of transitions will make the biggest difference.

I tried searching for a few online: here are a few examples I came across to give you some ideas:

These could lead to other strange artifacts, but could be a fun experiment that works for certain situations.

Otherwise, you'll need to get a new lens.

Marianne Oelund Veteran Member • Posts: 7,788
Apodization vs AF
1

beatboxa wrote:

One potential remedy would be to create a front filter that slowly diffuses from clear in the middle to darker on the outside, along the lines of this:

These are called "apodization" filters. Some portrait lenses have these built into the internal elements. For example, Fuji has 2 different versions of its 56mm F/1.2 portrait lens: (Right = embedded APD filter)

Such filters are only fully effective when the lens is used wide open.  Much of the bokeh edge softness in the Fuji lens is already lost when stopped down to f/1.8.

One problem with this approach will be in (potentially) significantly worse autofocus performance. This approach darkens the outer parts of the lens, which is where the samples for phase-detect autofocus are taken--if they're too dark too far center, AF will fail completely.

Usually, I find your posts to be well-considered and accurate, but this is a definite exception.  AF works just fine - even better in some cases - when the perimeter portions of the lens exit pupil are filtered or blocked.  The light paths used by Nikon PDAF are constrained to the central f/5.6 (or even f/8) portion of the exit pupil.

Example: the Fuji APD lens doesn't support PDAF.

If that's true, it is probably due to some linear polarization properties of the filter.

In addition, the image will be darker--this will give less priority to the light samples from the outside of the lens by reducing its intensity.

These filters don't have to be exact or perfectly smooth. You can try experimenting by getting a cheap, clear/UV filter, and trying to shade it yourself with markers or a series of layered ND filters. The speed and distance from center of transitions will make the biggest difference.

You can get away with this if the image only contains diffuse light sources - however, if there are specular highlights or small, intense sources, the pattern and shape of such filters will appear in the blur circles.

A better solution, although limited to slow to moderate shutter speeds and steady light sources (no flash), is to motorize these discs so that they are spinning.

-- hide signature --

Source credit: Prov 2:6
- Marianne

beatboxa Veteran Member • Posts: 7,962
Re: Apodization vs AF

Marianne Oelund wrote:

beatboxa wrote:

One potential remedy would be to create a front filter that slowly diffuses from clear in the middle to darker on the outside, along the lines of this:

These are called "apodization" filters. Some portrait lenses have these built into the internal elements. For example, Fuji has 2 different versions of its 56mm F/1.2 portrait lens: (Right = embedded APD filter)

Such filters are only fully effective when the lens is used wide open. Much of the bokeh edge softness in the Fuji lens is already lost when stopped down to f/1.8.

One problem with this approach will be in (potentially) significantly worse autofocus performance. This approach darkens the outer parts of the lens, which is where the samples for phase-detect autofocus are taken--if they're too dark too far center, AF will fail completely.

Usually, I find your posts to be well-considered and accurate, but this is a definite exception. AF works just fine - even better in some cases - when the perimeter portions of the lens exit pupil are filtered or blocked. The light paths used by Nikon PDAF are constrained to the central f/5.6 (or even f/8) portion of the exit pupil.

Example: the Fuji APD lens doesn't support PDAF.

If that's true, it is probably due to some linear polarization properties of the filter.

In addition, the image will be darker--this will give less priority to the light samples from the outside of the lens by reducing its intensity.

These filters don't have to be exact or perfectly smooth. You can try experimenting by getting a cheap, clear/UV filter, and trying to shade it yourself with markers or a series of layered ND filters. The speed and distance from center of transitions will make the biggest difference.

You can get away with this if the image only contains diffuse light sources - however, if there are specular highlights or small, intense sources, the pattern and shape of such filters will appear in the blur circles.

A better solution, although limited to slow to moderate shutter speeds and steady light sources (no flash), is to motorize these discs so that they are spinning.

Fair criticisms, and agreed on all points you raised.

I had assumed that the darker contrast from outer PDAF samples would have a greater effect on AF performance; but in retrospect, extending the comment to "failure" (or even 'significant' wouldn't apply since it's a front-filter, well before the aperture. D'oh!

Fuji's AF constraint may be different, since it's based on an internal apodization filter (rather than front)--and since it may well simply be an electronically enforced manufacturer constraint.

Keyboard shortcuts:
FForum MMy threads