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Author Topic: Halo problem when darkening blue skies  (Read 31522 times)

32BT

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Re: Halo problem when darkening blue skies
« Reply #20 on: August 12, 2013, 10:45:22 am »

Have you also tried to adjust the whitebalance? For optimal separation of sky and foliage?

As in:
1. set the HSL for blue to excessively dark
2. adjust the whitebalance temp until the halo disappears
3. reset the HSL for blue to something believable.

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Bart_van_der_Wolf

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Re: Halo problem when darkening blue skies
« Reply #21 on: August 12, 2013, 11:55:04 am »

Thanks, Bart.

The first crop of the straight ACR conversion looks the best to me. No halos at all.
It seems you've used Topaz Clarity and Focus Magic to darken the sky, sharpen the leaves which don't seem to benefit from sharpening, and produce halos which are not as obvious as in Redcrown's version, but still noticeable.

Hi Ray,

There are no halos, just luminance differences between leaf edges  and sky, and branch edges and sky. Topaz Clarity was only used to darken the L in HSL blue. The reflection edges are not the same color blue, therefore they don't darken by that HSL tweak. One could select other bluish tones and darken them, but then one really needs to do some advanced masking to avoid other image colors from being affected.

A simple way to do some crude edge darkening is by using the PS Select|Color range tool and click on the edge detail that you want to darken (it will have a mixed leaf/sky color), adding more to the selection with each click, subtracting if too much is added. Use a smallish range setting like 4 or thereabouts so you can be very selective. Then use that edge selection to create a mask on a duplicate layer, and darken that layer. You can dial in the amount of darkening in real time, so its not to difficult to judge how far to go. See attached example of what that can do in relatively little time. It's not perfect, but using a Polarization filter would have been a better approach if no wide angle lens is used. Prevention is still better than cure.

Quote
What I'd like to see is the first version with no halos at all, but with a darker sky as in the second and third versions. I guess this isn't possible. Right?

Well, not with a simple recipe, but with clever masking one can come a long way. Whether that is really making a better image is another question.

Cheers,
Bart
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Redcrown

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Re: Halo problem when darkening blue skies
« Reply #22 on: August 12, 2013, 01:27:13 pm »

OP here, and thanks again for all the effort and input. I think we're getting somewhere. Some comments and observations:

Kirkt said move the ACR Aqua slider to -100. I don't get that. When I do that I see no effect on the sky but some strange artifacts around the edges.

Paul2660's sample using C1 Pro is very impressive, but I don't have C1 and don't understand what technique he used after doing a "better selective color".

Some seem to think that the halos are the result of sharpening. I see halos with zero sharpening in ACR or Photoshop.

BartcanderWolf turned me on to Topaz Clarity for HSL adjustments. I have Clarity, but had used it only for the contrast enhancements. Never touched its HSL before. Some interesting potential there.

David Eichler thinks the halo effect is not in the original. I disagree. Blow up a leaf to 1000% and look closely at the edge. There is a definite change in luminosity and color in the 2 to 3 pixels at the edge. Almost always the case in bright sunlit scenes (due to diffraction).

Most interesting to me is the late comment by opgr, suggesting an adjustment of white balance in addition to darkening blue with HSL. I tried that and was amazed how the WB adjustment can actually change the white halos to black.

I did two ACR conversions, one normal, and one with a very bizzare and heavy handed darkening of blues with a WB that made dark halos. I layered the bizzare version on top of the normal one, changed it's blend mode to multiply or darken, then lowered its opacity until I got a sky and leaves I liked. That destroyed the rest of the image, but adding a simple channel mask easily fixed that. I just used a quickly tweaked blue channel from the normal conversion. I encourage others to play with that technique and see what you think.
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Kirk Gittings

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Re: Halo problem when darkening blue skies
« Reply #23 on: August 12, 2013, 02:29:09 pm »

This halo problem from darkening blue skies for b&w conversion is one of the reasons I stick with film and contrast filters for b&W landscape.
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Bart_van_der_Wolf

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Re: Halo problem when darkening blue skies
« Reply #24 on: August 12, 2013, 05:58:08 pm »

Most interesting to me is the late comment by opgr, suggesting an adjustment of white balance in addition to darkening blue with HSL. I tried that and was amazed how the WB adjustment can actually change the white halos to black.

I did two ACR conversions, one normal, and one with a very bizzare and heavy handed darkening of blues with a WB that made dark halos. I layered the bizzare version on top of the normal one, changed it's blend mode to multiply or darken, then lowered its opacity until I got a sky and leaves I liked. That destroyed the rest of the image, but adding a simple channel mask easily fixed that. I just used a quickly tweaked blue channel from the normal conversion. I encourage others to play with that technique and see what you think.

Hi,

Okay, in the category of extremely out of the box thinking:
1. Do a regular Raw conversion,
2. Create a duplicate layer, with Darker Color Blending mode
3. On that layer, apply a Topaz Black and White Effects filtering with the following settings:
3.1 Reset everything
3.2 Go to 3.Local Adjustments and select the Color adjustment type and the Color brush
3.3 Use a large brush and maximum Opacity and Hardness, with zero Edge Awareness
3.4 Now brush over the entire image, which replaces the B/W conversion with the original color
3.5 Now go to the 1. Conversion panel and only select the color filter
3.6 Select a yellow hue and a high strength which darkens the blue of the sky and brightens the leaves
3.7 Click OK to apply the filter.

Now you can adjust the opacity a bit, or play with the Blend-if layer blending options, and apply a coarse mask to avoid blue land-based colors from being affected.

Cheers,
Bart

P.S. A similar effect can be achieved within Photoshop. Create A duplicate layer in Luminosity Blending mode. Convert it to Black and White where you pull the blues and push the yellows and greens. Now create a composite layer with a Darker color blending mode, and eliminate the B/W conversion layer. Voila!
« Last Edit: August 12, 2013, 06:23:33 pm by BartvanderWolf »
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Ray

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Re: Halo problem when darkening blue skies
« Reply #25 on: August 13, 2013, 03:11:40 am »

Hi Ray,

There are no halos, just luminance differences between leaf edges  and sky, and branch edges and sky.......

.....Well, not with a simple recipe, but with clever masking one can come a long way. Whether that is really making a better image is another question.

Cheers,
Bart

Hi Bart,

As I recall, the introduction of the Shadows/Highlights tool in Photoshop, some years ago, was a major feature which made darkening highlights, and lightening shadows, much less complicated. One just moves the sliders back and forth till one gets the combination that produces the desired effect.

Likewise, I find that the 'blacks', 'shadows' and 'highlight recovery' sliders in the latest version of ACR 7 seem to produce a greatly improved effect. With this in mind, I thought it should be possible using these basic tools in ACR and Photoshop, to get the desired effect of a significantly darker sky without halos around the leaves.

I think I've achieved this effect using these basic tools. The attached images show the result. They have an embedded sRGB profile. Hope the colors appear as they do on my monitor.

Cheers!
« Last Edit: August 13, 2013, 04:17:25 am by Ray »
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32BT

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Re: Halo problem when darkening blue skies
« Reply #26 on: August 13, 2013, 06:07:23 am »

@Bart
You have exceeded your monthly quotum of the word "Topaz". In fact, when coming from you, combining "Topaz" with "out-of-the-box-thinking" is seriously stretching it.

@Ray
HDR look plus yellow cast??? You've been sucked into the instagram vortex, i take?
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32BT

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Re: Halo problem when darkening blue skies
« Reply #27 on: August 13, 2013, 06:23:26 am »

I keep wondering what OP is really trying to achieve. It could be a combination of these:

1. Create a deeper looking sky reminiscent of a clear, sunny day.

2. Add a ND grad effect for toning down the brightness of the sky.

3. Add a vignette effect for emphasizing the cart and flowers.

Depending on the needs, I believe that applying a simple ND grad effect in LR might proof very effective in achieving a desired result. I will also mention once more that a different choice of white balance would help the image in several ways.
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Bart_van_der_Wolf

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Re: Halo problem when darkening blue skies
« Reply #28 on: August 13, 2013, 06:40:59 am »

@Bart
You have exceeded your monthly quotum of the word "Topaz". In fact, when coming from you, combining "Topaz" with "out-of-the-box-thinking" is seriously stretching it.

Hi Oscar,

In that case, attached the step-by-step Action recipe as I recorded it with only Photoshop functionality, no T***z Labs plugins required. The Merge Visible with Duplicate step is achieved by holding down the ALT (OPTION on a Mac) key when selecting the layer palette menu option. I end the action with an 80% opacity step, but that's on the extreme side for my taste, around 50% would be more digestible. The 80% is chosen to avoid dark halos, and could be seen as the upper side of the opacity range one can use.

With extreme darkening, the sky blue may become a bit noisy, so either a simple Gaussian blur at e.g. 0.4 (we're only blending blue color back in, so we won't lose significant resolution), or a separate noise reduction on the new layer may be in order.

By also darkening the blue reflections on land-based surface areas and shadows, the whole effect looks a bit like using a polarizing filter. Of course, Blue objects in the scene need to be masked to avoid their color changing as well, but that mask can be very crude. Another nice side-effect is that the a*b* channel balance in L*a*b* coordinates is mostly unchanged (no magenta shift), because we only worked with the Luminosity, just as it should be before we decide to e.g. specifically change the blue saturation or vibrance.

Cheers,
Bart
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Ray

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Re: Halo problem when darkening blue skies
« Reply #29 on: August 13, 2013, 11:24:43 am »


@Ray
HDR look plus yellow cast??? You've been sucked into the instagram vortex, i take?

Oscar,
The purpose of the exercise was to create a dark sky without causing halos around the leaves and without causing blocked shadows. Whether or not the overall color balance and contrast is preferred, is another matter.
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Tim Lookingbill

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Re: Halo problem when darkening blue skies
« Reply #30 on: August 13, 2013, 03:56:58 pm »

And to be actually honest about this no one is showing their results at the OP's zoom view reference of 300% view where the halos are most pronounced, so no one is comparing apples to apples here.

At that zoom view a print's stochastic dithering is going to conceal that sliver of halo to the point it won't be seen at normal viewing distances including arm's length.

All in all too much time and work put into a problem that won't even be noticed, but at least we all got to see what can be accomplished with different editing approaches and software.
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Peterretep

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Re: Halo problem when darkening blue skies
« Reply #31 on: August 13, 2013, 04:46:11 pm »

When I first responded to this question I felt that the halos were the result of a a problem with a selection, that the selection was not encompassing the sky areas right adjacent to the leaves and branches, thus those unselected areas of sky remained undarkened and appearing as halos. Is this not the cause?

Peter

Tim Lookingbill

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Re: Halo problem when darkening blue skies
« Reply #32 on: August 13, 2013, 05:18:11 pm »

When I first responded to this question I felt that the halos were the result of a a problem with a selection, that the selection was not encompassing the sky areas right adjacent to the leaves and branches, thus those unselected areas of sky remained undarkened and appearing as halos. Is this not the cause?

Peter

All you have to do is zoom the edited version that show the halos most pronounced to where you can see individual pixels like maybe 600% view in Photoshop. Sample the RGB readings of the white within the halos to see if there's enough blue. HSL in ACR/LR smoothly tapers off the area of selection in gradual manner. If it was too precise noise would start to kick up along lens induced edge aberrations similar to leaf halos.

Something I hadn't consider might work better and that is to use the saturation/hue sliders in the Camera Calibration panel of ACR/LR. It might offer a more refined gradualness that reaches farther into the white of the halos if they really are completely R=G=B. They might just be greenish white. Hard to tell.
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Ray

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Re: Halo problem when darkening blue skies
« Reply #33 on: August 13, 2013, 08:45:41 pm »

And to be actually honest about this no one is showing their results at the OP's zoom view reference of 300% view where the halos are most pronounced, so no one is comparing apples to apples here.

At that zoom view a print's stochastic dithering is going to conceal that sliver of halo to the point it won't be seen at normal viewing distances including arm's length.

All in all too much time and work put into a problem that won't even be noticed, but at least we all got to see what can be accomplished with different editing approaches and software.

Good point! Here's my 300% crop showing negligible halo effects.

No fancy third-party programs required, and no fancy layering techniques, other than basic ACR adjustments, Shadows/Highlights tool in Photoshop, and a couple of selections with Magic Wand and Quick Selection tool. Oh! And a click on the Auto Contrast button.

What do you think?
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Ray

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Re: Halo problem when darkening blue skies
« Reply #34 on: August 13, 2013, 09:27:50 pm »

If anyone is interested, attached are the basic adjustments I started from. In ACR, three moves to the right and three moves to the left. In Shadows/Highlights, four moves to the right. After that, I selected the flowers to brighten them, and clicked on the Auto Contrast button. I also selected the sky with the Magic Wand, feathered by 2 pixels, and applied a little Gaussian Blur to soften the grain in the sky which was noticeable at 300%. If I were processing the image for sale or for print I would make other adjustments, but as I mentioned, this was just an exercise using PS6, to see how I might overcome this halo problem that I've experienced in the past when trying to do this sort of thing.
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Tim Lookingbill

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Re: Halo problem when darkening blue skies
« Reply #35 on: August 14, 2013, 12:27:08 am »

Good point! Here's my 300% crop showing negligible halo effects.

No fancy third-party programs required, and no fancy layering techniques, other than basic ACR adjustments, Shadows/Highlights tool in Photoshop, and a couple of selections with Magic Wand and Quick Selection tool. Oh! And a click on the Auto Contrast button.

What do you think?

I think that's a phenomenal job on that 300% zoomed section of the image, but not so good for the rest of the image which is quite dark and dim for a shot of a cloudless, midday sunlit scene which should look bright.

Is eliminating thin halos on some leaves that aren't an integral part of the image and won't be seen on a print worth making the rest of the image look like that? Sometimes you just have take what you got and move on to better shots.

From my editing around 3000 6MP Raws primarily of similarly lit landscapes I never gave white leaf halos any thought of concern. And the OP is working with much higher resolution images.

First there were Pixel Peepers which I am a member of that club and now with this image...Picky Pixel Pickers™ ;D
« Last Edit: August 14, 2013, 12:30:12 am by Tim Lookingbill »
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Ray

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Re: Halo problem when darkening blue skies
« Reply #36 on: August 14, 2013, 09:29:51 am »

I think that's a phenomenal job on that 300% zoomed section of the image, but not so good for the rest of the image which is quite dark and dim for a shot of a cloudless, midday sunlit scene which should look bright.

Is eliminating thin halos on some leaves that aren't an integral part of the image and won't be seen on a print worth making the rest of the image look like that? Sometimes you just have take what you got and move on to better shots.

From my editing around 3000 6MP Raws primarily of similarly lit landscapes I never gave white leaf halos any thought of concern. And the OP is working with much higher resolution images.

First there were Pixel Peepers which I am a member of that club and now with this image...Picky Pixel Pickers™ ;D

Tim,
I agree. The image is too dark for a sunny day. But as I mentioned, those adjustments in ACR and Shadows/Highlights were the starting point. I was just trying to see how much of a difference in luminance between the sky and the foliage I could get, using basic techniques that anyone could use, before halos became obvious. I've gone back to the image and lightened it, by special request.  ;D

Is this better?
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Tim Lookingbill

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Re: Halo problem when darkening blue skies
« Reply #37 on: August 14, 2013, 06:00:00 pm »

Tim,
I agree. The image is too dark for a sunny day. But as I mentioned, those adjustments in ACR and Shadows/Highlights were the starting point. I was just trying to see how much of a difference in luminance between the sky and the foliage I could get, using basic techniques that anyone could use, before halos became obvious. I've gone back to the image and lightened it, by special request.  ;D

Is this better?

Much better on the brightness end, Ray, but there's a heavily saturated yellow cast on almost every element that's not sky. The yellow pine wagon seat doesn't look real.

I don't know if that effect is a result of using S/H or maybe our monitor calibration/profiling are not showing what you intend. I'll show a screen shot off my calibrated 27" LG LED next to what new yellow pine should look like on a wagon.
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Ray

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Re: Halo problem when darkening blue skies
« Reply #38 on: August 14, 2013, 08:44:56 pm »

Much better on the brightness end, Ray, but there's a heavily saturated yellow cast on almost every element that's not sky. The yellow pine wagon seat doesn't look real.

Ah! Tim, but that pine wagon seat has been triple-coated with the best quality polyurethane varnish. It's brand new. Compare it with the rest of the wagon which is very dull and weather beaten.

Nevertheless, I agree that the image has a yellow overcast, so I've tweaked the color a bit using  Hue/Saturation and Color Balance sliders. I've also taken the gloss off the seat, to make it more in character with the rest of the wagon.

Better?  ;D
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Tim Lookingbill

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Re: Halo problem when darkening blue skies
« Reply #39 on: August 14, 2013, 09:13:00 pm »

Ah! Tim, but that pine wagon seat has been triple-coated with the best quality polyurethane varnish. It's brand new. Compare it with the rest of the wagon which is very dull and weather beaten.

Nevertheless, I agree that the image has a yellow overcast, so I've tweaked the color a bit using  Hue/Saturation and Color Balance sliders. I've also taken the gloss off the seat, to make it more in character with the rest of the wagon.

Better?  ;D


Oh yeah, much better. I like the way you brought out all the detail in the wagon undercarriage that was completely obscured in shadow.

Hey, I guess we're a PP team.  ;D
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