Halo on edge of selections

[Ian Homewood]

Hi

I know this has been asked before, but I have just spent the past two hours dredging the forums and have not found a practical answer to my problem.

I have a photo of the Quiraing, on the Isle of Skye.  I need to separate foreground from sky, so that I can tweak their respective brightnesses.  Selecting and separating the sky is no problem, but when I apply the brightness adjustment to the foreground I get a really noticable halo along the edge of the selection area.

I have tried all sorts of different settings in the 'Refine' dialogue, but nothing seems to get rid of the halo.  I've tried some of the techniques listed on here, but they are hit and miss because of the mountainous terrain in this image.

I have also tried creating a sky layer, a foreground layer and leaving the original image ticked, but that makes no difference either.

I'm sure there must be a way to do it but I'm fairly new to Affinity and cannot find it.

I've attached the file if anybody is willing to take a look.

Thanks in advance

Ian

[v_kyr]

Did you already tried what is shown as selection refinement and masking in this one from the online tutorials?

• Sky replacement (Updated: 24/10/2020)
• Selection refinement
• Masking adjustment layers

[Ian Homewood]

Yes thanks, I have used selection refinement, as per my original post.  I've tried reducing the border to 0% but it still leaves a border.  I've tried selecting the foreground instead of the sky, which produces a different appearance on the halo.

I know that I could use a small adjustment brush on the halo, to reduce or remove it, but that would be extremely time-consuming given that the halo is right the way across the frame.

I have used this process a lot, but the brightness adjustment on other photos has always been fairly small.  This time I need to brighten the foreground a good couple of stops and that is when the halo appears.  I cannot work out though, why there should be a halo even when there is no feathering, smoothing or border width.  It seems to make no sense.

Thanks

Ian

[Marina2020]

Hello Ian. 

I see I am not alone... I am trying to take a photo of a beer bottle with a backlight bouncing on the wall and with a diffusion between bottle and flash. Everything is ok until I cut out the bottle. Then it appears a halo in white all around the edges of the bottle. I als have tried the refine tool to remove it but nothing happens. I'm also wondering if I am missing something or if Affinity has no tool for this...

I´ve attached the image so that you can take a look. Of course when the background is white you don't see the halos. I don't know, maybe I am becoming crazy, but I see other photos of beer bottles with black background and this halos are not there... I know Photoshop has also the refine tool and in some Youtube-Videos you can see it works. There is a function (I don't know the name in englisch) but it makes the bottle a bit thinner, so that the halo is gone. 

What do you think? 

[John Rostron]

On 12/30/2020 at 5:18 PM, Ian Homewood said:

I've attached the file if anybody is willing to take a look.

We may be able to help futher if you attach the file as promised.

John

[Chris26]

Might Help: Note that Halos are easily removed but can be prevented if you do not employ heavy editing techniques in shadows and highlights, maybe adopt gentler techniques for highlights and shadows such as the Lumnosity mask or the use of LAB colour space, even unsharp mask cn be used for increasing contrast without actually sharpening anything,  But generally Halos are a result of heavy editing,

https://www.photocascadia.com/easily-fix-edge-halos-with-darker-color-cloning/

https://www.australianphotographer.com/tip-22-halo-removal

[Ian Homewood]

1 hour ago, John Rostron said:

We may be able to help futher if you attach the file as promised.

John

Hi John

I definitely attached the file and have no idea why it isn't visible, I'll try again. 

Ian 

[Ian Homewood]

43 minutes ago, Chris26 said:

Might Help: Note that Halos are easily removed but can be prevented if you do not employ heavy editing techniques in shadows and highlights, maybe adopt gentler techniques for highlights and shadows such as the Lumnosity mask or the use of LAB colour space, even unsharp mask cn be used for increasing contrast without actually sharpening anything,  But generally Halos are a result of heavy editing,

https://www.photocascadia.com/easily-fix-edge-halos-with-darker-color-cloning/

https://www.australianphotographer.com/tip-22-halo-removal

Thanks. In this instance I need to increase exposure quite a lot. However what I don't understand is why there is any halo at all. The halo is brighter than the selection which makes no sense, especially when feathering, smoothing and border are all set to zero. 

Ian 

[Chris26]

2 hours ago, Marina2020 said:

What do you think? 

As for the Bottle man here is your solution:

[Chris26]

29 minutes ago, Ian Homewood said:

In this instance I need to increase exposure quite a lot.

I need see your image, otherwise I can not do anything.  If you look at the video above I have solved hs issue, but I really need to see your image.

[Ian Homewood]

I have just found out why the file is not available. Apparently a 200mb limit is being applied, even though the dialogue says 2gb.

I'll see if there is any way I can reduce the size. 

[Ian Homewood]

I'm not at home at the moment, will look at the video when I get back. 

Thanks

Ian 

[Ian Homewood]

Okay.  I've had to get rid of the original background layer to get the file to upload, but you should be able to see it now.  I'm home so will take a look at the video.

I have also uploaded the original as a separate file.

If I could understand where the halo comes from it may help.  If I set feather, smooth and border to zero I would expect the selection to have an absolutely hard edge, but the halo still appears.  I'm stumped.

Thanks for your help.

Ian

Quiraing_sml.afphoto

Quiraing_original.afphoto

[Ian Homewood]

Just been having another play.  There seem to be ways to reduce the halo, by doing the adjustments in small bites, though not to totally eliminate them.

Can anybody explain exactly what the halo is please?  I understand sharpening halos, but not why there should be a halo at the edge of a selection when the exposure or brightness is changed.  In this image it appears as a green halo, which tends to suggest that it is something to do with the content of the selection.  Does the selection brush do something to the edges?

Still confused.

Ian

[Chris26]

1 hour ago, Ian Homewood said:

Okay.  I've had to get rid of the original background layer to get the file to upload, but you should be able to see it now.  I'm home so will take a look at the video.

I have also uploaded the original as a separate file.

If I could understand where the halo comes from it may help.  If I set feather, smooth and border to zero I would expect the selection to have an absolutely hard edge, but the halo still appears.  I'm stumped.

Thanks for your help.

 

If this is the original no adjustments file (I switched them off) and I notice your aperture was an F11 which is reasonably wide, then all this is Chromatic aberation.  Mostly Blue.  If you take a look a look at the screen shot I took you will notice that there is no fringing between the two hills where I put the black arrow, but only where the light is hitting the mountains.  Wide aperatures tend to do this in these conditions, although not with every lens I imagine.  I have not looked but you should be able to get rid of this in the DNG when you first load it into A.photo.  And to my utter shock and horrow, I see no options for eliminating chromatic aberation in affinity, so I guess you have to do it the long way in photo itself.  I have not looked into this but there are plenty of youtubers who might have done this already in affinity  Photo.

EDIT:  may I suggest you consider using a neutral grey filter in these conditions, where the darker part of the filter would be positioned over the sky and the lighter part over the land.  You will be surprised at how much less editing you will need to do with also a polarising filter. Also I always OVER expose my images even in bright conditions, a rule of thumb is that the camera always lies, in other words it attempts to reduce everything to neutral grey.  In film photography we UNDER expose, in digital, We OVER expose by at least 2/3 of a stop, check your histogram and get as much information as possible to fall all the way to the right of the histogram, it then becomes a simple matter of pulling back the highlights in the RAW editing stage.  You can not add information but you can always remove some is a rule of thumb.

 

[John Rostron]

4 minutes ago, Chris26 said:

And to my utter shock and horrow, I see no options for eliminating chromatic aberation in affinity, so I guess you have to do it the long way in photo itself.  I have not looked into this but there are plenty of youtubers who might have done this already in affinity  Photo.

You should be able to do it if you start with a raw file. Use the defringe option (Lens > Chromatic Abberation Reduction). It will also work if you go to the Develop Persona from the original background layer (not the separations).

John

[Ian Homewood]

Thanks Chris.  I'm surprised if it is CA, as I don't normally get that with this lens.

I think I have answered my own question about the green halo.  In that experiment I had been adjusting the contrast, so the halo was probably edge detection for that adjustment.

In my latest experiment I have done away with the selection brush.  Instead, I adjusted the exposure of the entire image and then used the paintbrush to remove the adjustment from the sky area.  In close up there is no halo, though there is the tiniest purple fringe along the top of the ridge on the right.  Maybe that file I sent you wasn't the original original.  I've been going around with this for so long it's possible I saved a copy with some initial adjustments made.

I've uploaded the current version, so you can see the difference.  IMHO the halo is definitely to do with the selection brush, when one or both areas need more than a slight adjustment to the brightness and/or contrast.

Thanks for all of your help.

Ian

Quiraing_adj_brush.afphoto

[Chris26]

7 minutes ago, John Rostron said:

You should be able to do it if you start with a raw file. Use the defringe option (Lens > Chromatic Abberation Reduction). It will also work if you go to the Develop Persona from the original background layer (not the separations).

John

Ah thanks John, yes I was hoping that, I did not have his DNG.  And I hope that the OP has the originl in DNG then he can start again.

[Ian Homewood]

5 minutes ago, John Rostron said:

You should be able to do it if you start with a raw file. Use the defringe option (Lens > Chromatic Abberation Reduction). It will also work if you go to the Develop Persona from the original background layer (not the separations).

John

Thanks John I'll take a look

[Chris26]

4 minutes ago, Ian Homewood said:

Thanks John I'll take a look

I edited my original message just in case you missed something.

[Ian Homewood]

4 minutes ago, Chris26 said:

Ah thanks John, yes I was hoping that, I did not have his DNG.  And I hope that the OP has the originl in DNG then he can start again.

Yes I always keep my raw files thanks.

[Chris26]

13 minutes ago, Ian Homewood said:

Instead, I adjusted the exposure of the entire image and then used the paintbrush to remove the adjustment from the sky area.

A little tip here.  No Need at all to do any selections and masking.  Watch the video, this saves time and is more efficient, I have not done it precisely because I just wanted to give you an insight.  Notice how none of the adjustments have affected the sky.

 

[Ian Homewood]

Thanks, I'll take another look, but that last attempt didn't use selections or masking.

[user_0815]

On 1/2/2021 at 2:16 PM, Marina2020 said:

Hello Ian. 

I see I am not alone... I am trying to take a photo of a beer bottle with a backlight bouncing on the wall and with a diffusion between bottle and flash. Everything is ok until I cut out the bottle. Then it appears a halo in white all around the edges of the bottle. I als have tried the refine tool to remove it but nothing happens. I'm also wondering if I am missing something or if Affinity has no tool for this...

I´ve attached the image so that you can take a look. Of course when the background is white you don't see the halos. I don't know, maybe I am becoming crazy, but I see other photos of beer bottles with black background and this halos are not there... I know Photoshop has also the refine tool and in some Youtube-Videos you can see it works. There is a function (I don't know the name in englisch) but it makes the bottle a bit thinner, so that the halo is gone. 

What do you think? 

In this case I think it's less a halo. What I see here is a reflection of the bright background.