Please check out my image "Enjoying Lunch" in the Wildlife Gallery. How do I eliminate the halos caused by selective darkening or lightening around a subject ? I know I could go in an use the brush tool but that would take off the edge of the bear's hair. Any input or Photoshop tricks appreciated !!!
Thanks in advance
Andrew
Posted by John Mumaw on September 9, 2011 at 8:41 PM
On a duplicate image, select enough of the water around the bear's head and back to encompass the haloed areas using the Quick Selection tool. Before you begin, choose a smallish selector brush (20px +/-), set the Hardness to 100% and the Spacing to 0 and check the AutoEnhance box.
Make the selection, and then click on the Refine Edge button. In the dialog box that appears, check the Smart Radius box and move the Radius slider 2 or 3 px. This will help tighten up the selection around the hair.
When you have the area selected, start cloning in from other areas of the water. No need to worry about the hair, as the Clone tool will only work in the selected area (the water).
Posted by David Bostedo on September 10, 2011 at 12:26 PM
Rather than ask how to "fix" the halo, I would like to know what caused it in the first place. I think avoiding the creation of it will be MUCH better than trying to fix it now.
Posted by Richard Ditch on September 10, 2011 at 12:52 PM
David has expressed my thoughts as well.
Halos as in the referenced image often come from quick attempts to change tomes - most often to lighten under-exposed parts of the image or to darken over-exposed parts. Those problems are best addressed by getting the exposure correct at the time the image is made.
When exposure is off a bit and the image needs some modest fine tuning then other factors come into play. A tempting but dangerous tool is the shadow/highlight adjustment in photoshop. Duplicate the layer, then make a careful selection of the area needing work. Keep the sliders of S/H to the left and don't try to make big tonal changes. Toggle the duplicate layer on/off to judge the effect, and use the layer mask to fine tune the edges.
For burning or dodging, add a new layer and fill it with 50% gray set to soft light. Set the FG/BG colors to default B&W. Then use a soft edged brush at low intensity (10-20%) and paint on the new layer with black to darker and white to lighten the underlying image. Toggle the layer on/off to judge progress. Switch colors to fix spillovers or reduce spots where the correction went too far.
Thanks for all the great tips. I was trying to adjust the color tone of the water behind the bear with the lasso tool as I put my efforts on getting the bear exposure perfect as shot.
I do appreciate all the knowledge shared.
Andrew
Posted by David Bostedo on September 10, 2011 at 3:41 PM
Andrew - I thought it was likely because of wanting to darken the water. There are plenty of ways to do it without using the lasso tool or causing halos. I agree the the exposure of the bear is most important.
Posted by Richard Ditch on September 10, 2011 at 3:41 PM
Andrew:
Sounds like your issue then is in making a proper selection of the water for the tonal change. I'm no fan of the lasso tool; I prefer to use the Quick Select or Magic Select (not sure what it is called in various releases of photoshop), or I make a selection using color.
Posted by Andreas Resch on September 15, 2011 at 7:58 AM
To be able to nicely remove the halos you definitely should isolate the bear with a mask. Cosidering the fact that each image has 10 channels (RGBCMYKLab) you can dig into them to see which one will give you the best mask. You can do that by hovering over adjacent areas and checking the color values in the "Info" palette of Photoshop. There you easily switch between the color modes and see in which one a certain channel value jumps most when you move from the background to the bear in this case.
For this one it looks as if the "a" channel of the Lab color mode might be a good choice. The "a" value of the background is mostly negative due to it's green hue and the warm tones of the fur contain quit a bit of magenta which is positive in the "a" channel. So you best create a duplicate of the image and convert it to Lab mode. From there you process the "a" channel with levels or curves and then bring that channel back to the original image to use as a mask (simple copy/paste). There you duplicate the layer containing the complete image and apply the just created alpha channel to it so that all modifications you make just affect the background and leave the bear unharmed. Due to the indestructive nature of the mask you can even adjust the mask if needed.
I hope this wasn't too much info ... you might find some tutorials if you google for "create mask from Lab mode channel" or something. Sometimes you can even find little tutorial on Youtube. Good luck.
Discussion
7 repliesThanks in advance
Andrew
Make the selection, and then click on the Refine Edge button. In the dialog box that appears, check the Smart Radius box and move the Radius slider 2 or 3 px. This will help tighten up the selection around the hair.
When you have the area selected, start cloning in from other areas of the water. No need to worry about the hair, as the Clone tool will only work in the selected area (the water).
Halos as in the referenced image often come from quick attempts to change tomes - most often to lighten under-exposed parts of the image or to darken over-exposed parts. Those problems are best addressed by getting the exposure correct at the time the image is made.
When exposure is off a bit and the image needs some modest fine tuning then other factors come into play. A tempting but dangerous tool is the shadow/highlight adjustment in photoshop. Duplicate the layer, then make a careful selection of the area needing work. Keep the sliders of S/H to the left and don't try to make big tonal changes. Toggle the duplicate layer on/off to judge the effect, and use the layer mask to fine tune the edges.
For burning or dodging, add a new layer and fill it with 50% gray set to soft light. Set the FG/BG colors to default B&W. Then use a soft edged brush at low intensity (10-20%) and paint on the new layer with black to darker and white to lighten the underlying image. Toggle the layer on/off to judge progress. Switch colors to fix spillovers or reduce spots where the correction went too far.
I do appreciate all the knowledge shared.
Andrew
Sounds like your issue then is in making a proper selection of the water for the tonal change. I'm no fan of the lasso tool; I prefer to use the Quick Select or Magic Select (not sure what it is called in various releases of photoshop), or I make a selection using color.
For this one it looks as if the "a" channel of the Lab color mode might be a good choice. The "a" value of the background is mostly negative due to it's green hue and the warm tones of the fur contain quit a bit of magenta which is positive in the "a" channel. So you best create a duplicate of the image and convert it to Lab mode. From there you process the "a" channel with levels or curves and then bring that channel back to the original image to use as a mask (simple copy/paste). There you duplicate the layer containing the complete image and apply the just created alpha channel to it so that all modifications you make just affect the background and leave the bear unharmed. Due to the indestructive nature of the mask you can even adjust the mask if needed.
I hope this wasn't too much info ... you might find some tutorials if you google for "create mask from Lab mode channel" or something. Sometimes you can even find little tutorial on Youtube. Good luck.