Ad
Ad
Ad
Pages: « 1 2 3 [4]   Bottom of Page
Print
Author Topic: Halo problem when darkening blue skies  (Read 15777 times)
Rory
Full Member
***
Offline Offline

Posts: 195


« Reply #60 on: August 17, 2013, 11:49:30 AM »
ReplyReply

Well that makes several people that have this problem, Rory.

Is that useful information in getting it solved? No.

Does your input prove it's wide spread? No.

In an attempt to draw useful information out of you I have to ask you did anyone at Adobe or anyone else offer any causes or solutions in those past discussions?

So far from this discussion it appears the solution as Stephane has demonstrated is to use Nik Silver Efex Pro as a Smart Object or use another Raw converter.

I'm just saying it is easy to replicate this behavior, even if not apparently by you.  I am also saying it is a widely known issue even if you were not aware of it.  I do not have the time to search to find the relevant threads, but it is mentioned (at least the auto mask component) in Jeff's digital negative book.  It is not a really big deal and other software, as mentioned, does not create the halos. I find it is more of an issue for creative editing rather than normal photo editing and takes a fairly extreme adjustment to manifest.
Logged
StephaneB
Jr. Member
**
Offline Offline

Posts: 69


WWW
« Reply #61 on: August 17, 2013, 11:58:12 AM »
ReplyReply

Just for the Record Tim, I have been seeing this halo behavior since Lr 1.0.  It has been discussed in the past.  It takes a fairly extreme adjustment to manifest.  It is particularly problematic using an adjustment brush in auto mask mode.

Rory

Thanks Rory. I'd only add that I understand it takes extreme adjustments in color, but in B&W mode, just replicating the effect of a red filter on a blue sky will make it appears nearly every time. Before knowing how to avoid it, I stuck to film.
Logged


Stéphane

My Webpage

Arlen
Full Member
***
Offline Offline

Posts: 151


« Reply #62 on: August 17, 2013, 07:53:37 PM »
ReplyReply

I don't know about Capture One, but in LR/ACR getting halos when darkening selections like skies is definitely an issue--especially with the Auto Masked adjustment brush. But that's true for any commonly used edge-bounded method that I've tried, including Photoshop's selection tools such as Magic Wand or Color Range. I've been checking out other techniques to get around those limitations.

The problem is made harder though in the example presented to us by Redcrown because of the nature of the image file. The image is a little too overexposed for easy post processing to a good blue sky. The white flowers are blown out. I would have preferred an exposure about 1 stop less to allow for easier sky recovery. Also, in the original file presented to us, the custom WB has added a yellowish cast, greatly warming the sky and rendering it less blue—making the job of recovering the blue color much more difficult. Those factors force us to make radical adjustments to recover the sky, which accentuate any artifacts.

Lots of you have taken a shot at processing Redcrown's file, and it has been fun and informative to read through. Let me add some remarks about my own attempt, which I think was successful. I stuck with LR4.4 and PS CS6, since that's what most of us use.

I processed first through LR, beginning by resetting Redcrown's dng file adjustments back to default. That included setting the WB to "As Shot", which removes the yellow cast and gives us a good start on that blue sky. Then I optimized various other settings to get the whole image looking as good as possible (to me), without pushing any parameter so far as to cause artifacts. I think the resulting image from LR looks fine, with no halos that will be noticeable in a moderately sized print.

But to get the sky a little darker yet, I took it into CS6 and used a couple of luminosity and gradient masks, together with Levels adjustments, to modestly darken just the brightest tones (sky) in the upper part of the frame. A major advantage of luminosity masks is their ability to automatically feather between contrasting objects in a smooth, natural way. If you don't know about luminosity masks, do a search for them to get to Tony Kuyper's tutorials. He a master of luminosity masking.

Attachments showing the full images are at the bottom of this post, and I would suggest looking at them first.

The following embedded images are 100% crops of the leaves, which to my eye show no artifacts induced by the processing, but as others have noted there are some specular reflections on the edges of some leaves present even in the unadjusted file.

Redcrown's original DNG


LR4.4


LR4.4 + Luminosity Masking in CS6



The first attachment below is a jpeg of the full image generated in LR from Redcrown's "original" dng file, with his settings exactly as I received them. No output sharpening was applied to it or to any of the other attached or embedded images here. Redcrown's file included some capture sharpening, and my versions modified that down to default sharpening settings, which seemed more appropriate to me.

The second attachment is the full image adjusted in LR only, by me.

The third attachment is the full image adjusted in LR plus Luminosity Masking in CS6.

The fourth attachment is a text file describing the steps that were taken in LR and CS6, for anyone interested.

I also have a screen capture of the LR settings that were used, that I can post if requested.

Logged
Fine_Art
Sr. Member
****
Offline Offline

Posts: 1157


« Reply #63 on: August 18, 2013, 01:59:26 PM »
ReplyReply

I often try to darken the blue in landscape skies. I've tried several techniques to darken the blue, but all leave halos around tree leaves, branches, and other hard edges. I know the halos are the result of natural light diffraction around edges. I've tried various techniques to remove the halos after the fact, but can't find anything that works well, other than tedious pixel level cloning. Wondering if anybody has a good method.

Here is a recent example, full frames on top, 200% crops on the bottom to show halos. The images on the left are before darkening the blues. The ones on the right are the result of using the HSL tab in ACR and dragging the blue luminosity slider all the way to the left.

Sometimes I try a B&W adjustment layer in luminosity mode and drag its blue/cyan sliders. Sometimes I try a Selective Color adjustment layer. All give similar results and halos.



Anybody wants to play, here is the raw/dng file.

https://dl.dropboxusercontent.com/u/62166185/ANwedding040v0.dng

It seems like most white sky fringing is a byproduct of sharpening methods.
Logged
StephaneB
Jr. Member
**
Offline Offline

Posts: 69


WWW
« Reply #64 on: August 20, 2013, 02:49:12 PM »
ReplyReply

Quote from: Fine_Art
It seems like most white sky fringing is a byproduct of sharpening methods.

Actually no. They appear even in the absence of sharpening.
Logged


Stéphane

My Webpage

Fine_Art
Sr. Member
****
Offline Offline

Posts: 1157


« Reply #65 on: August 20, 2013, 10:09:47 PM »
ReplyReply

Actually no. They appear even in the absence of sharpening.

What software are you using?
Logged
StephaneB
Jr. Member
**
Offline Offline

Posts: 69


WWW
« Reply #66 on: August 21, 2013, 12:23:51 AM »
ReplyReply

Quote from: Fine_Art
What software are you using?

I suggest your read the thread.
Logged


Stéphane

My Webpage

Fine_Art
Sr. Member
****
Offline Offline

Posts: 1157


« Reply #67 on: August 21, 2013, 10:58:18 PM »
ReplyReply

Ok, I have read the rest that I skipped before (P 2,3). I just dont have this problem with my software. Maybe because any time I am making adjustments that start to trash the image with strange effects I back it off to where I was before. I Do remember having some trouble with some images of very golden leaves in the fall. Maybe try bracketing 1ev the use the sky from the darker shot. Just using the shot in the original post putting the image to -1.2 exposure did not create any problem at 400% view. If you have only 1 shot try -1ev exposure slider then layer that sky with the rest of the shot as normal.
Logged
Rory
Full Member
***
Offline Offline

Posts: 195


« Reply #68 on: August 22, 2013, 09:50:41 AM »
ReplyReply

I found this thread in Adobe feedback that I started over 2 years ago.  Here are a couple of excerpts of examples I posted to the thread:

Quote
When painting with the adjustment brush with a exposure change along a high contrast boundary a halo is created. Eliminating this behavior, or a "halo cleanup" tool would be very helpful.

Here is an example:


Quote
Here is an example, where I painted in a bright color to illustrate the effect on tree branches. I also filled in the area with a color using Nik Color Efex Pro to show that it can be done properly.



So, until Adobe fixes this issue one alternative is to use NIK filters and U-point masking.
Logged
Kirk Gittings
Sr. Member
****
Offline Offline

Posts: 1553


WWW
« Reply #69 on: August 22, 2013, 02:15:25 PM »
ReplyReply

Can the NIK program do this on related colors though like green leaves and blue skies?
Logged

Thanks,
Kirk

Kirk Gittings
Architecture and Landscape Photography
WWW.GITTINGSPHOTO.COM

LIGHT+SPACE+STRUCTURE (blog)
Rory
Full Member
***
Offline Offline

Posts: 195


« Reply #70 on: August 22, 2013, 07:11:24 PM »
ReplyReply

Can the NIK program do this on related colors though like green leaves and blue skies?

Yes.

Logged
smahn
Full Member
***
Offline Offline

Posts: 132


« Reply #71 on: August 22, 2013, 11:21:06 PM »
ReplyReply

In the Nik shot it appears to be overlaying the branch with color too, IOW not even attempting to find and work within boundaries.
Logged
Rory
Full Member
***
Offline Offline

Posts: 195


« Reply #72 on: August 23, 2013, 10:01:45 AM »
ReplyReply

In the Nik shot it appears to be overlaying the branch with color too, IOW not even attempting to find and work within boundaries.

I see that too, but the NIK is still much better.  I think there is room for optimism that Adobe will tweak this in the future.
Logged
Arlen
Full Member
***
Offline Offline

Posts: 151


« Reply #73 on: August 23, 2013, 10:07:22 AM »
ReplyReply

With the NIK software, you can put negative control points on the branches, or other areas you want to exclude, and that will usually do a good job of preventing spillover of the effect into those areas.
Logged
StephaneB
Jr. Member
**
Offline Offline

Posts: 69


WWW
« Reply #74 on: August 23, 2013, 11:40:46 AM »
ReplyReply

@StephaneB. My virus scanner tells me that there is a virus at your website. Maybe you want to check that.

Thanks. It is now fixed.
Logged


Stéphane

My Webpage

Pages: « 1 2 3 [4]   Top of Page
Print
Jump to:  

Ad
Ad
Ad