The Radial Filter - A Most Useful Tool
In the article on Leading Light I referred to learning techniques on how to create light in your photos and referred you to the now slightly outdated YouTube video by Serge Ramelli. This video on the use of radial filters to create light is the technique I have employed the most for adjusting light in areas of my images. The radial filter is simply a mask that affects portions of your image. As used in Lightroom or Adobe Camera Raw, you don’t actually see the mask as a separate layer the way you would if you were just creating a mask on a separate layer in Photoshop. Since you don't see the mask when you are back in the layers panel in Photoshop, you will have difficulty making changes changes to the mask as you work. For this reason, it is good practice to duplicate your current layer (or copy multiple layers and merge them if the top layer isn't 100% opacity) and label the new layer with the actions you are performing on that layer each time you go back in forth from PS to ACR. Some users prefer to work solely in LR. If you do this, you will want to use the History panel in LR to keep track of your actions.
Since we have already used the radial filters in the Leading Light article, this month’s article is going to describe ways you might want to adjust your radial filters by applying additional filters (masks) to them. Next month we will cover more challenging masks and the uses of a more recent addition to Adobe’s programs, the Object Selection tool.
The image below has initial global changes performed on the RAW file in Lightroom. If you are not experienced in using the masking tool in LR or ACR, it is suggested that you work along on with the image on your computer. Find a high quality jpg here.
I generally start with a plan. There are several areas that I would like to modify where I might apply the Radial Filter in conjunction with other filters (masks). These are:
1. Accentuate the blowing rain on the right side. Since the rain crosses the horizon line, it is not will not work to separate the sky from the land using the sky selection filter.
2. Create increased warmth on the sunlit areas in the lower center.
3. Increase the luminance of the river.
4. Increase the luminance of the inversion layer clouds in the center of the image.
5. Increase the contrast of the ridges that are closest to the viewer.
If you have never used a mask in Lightroom or Adobe Camera Raw, review this section to understand the steps you will take to start with a mask. Once you have your mask placed over the image, any changes you make with the available sliders will only change the masked area.
It is common to work with the shown panel on the right side of your computer screen. The yellow numbers have been added.
(1) Shows the MASK SELECTION button. When you select this button you will open up a your mask selection choices shown in the figure below. You will then drag the mask over the image with your mouse of keypad. The selected mask will have handles that allow it to be modified in size or rotated.
(2) For the image in process the RADIAL GRADIENT has been selected. If you choose to work with multiple masks, they will show as a stack in LR. They will show as a stack in ACR also, except each time you close ACR to return to Photoshop, then return to ACR you will not have a record of your previous masks displayed.
(3) When you first drag a mask into place over an image, it will show as the color you have selected. I usually select a lime green or pink mask. You may select from any color that helps you visualize your selection area. Note that all of the sliders below are set to a zero starting point. As soon as you move a slider, the colored mask overlay will disappear so you can visualize the change you have made.
(4) The feather tool allows you to move from a very sharp edge (no feathering) to a very blended edge. In general, avoid a sharp edge and be sure to feather enough so your work does not look artificial, but not so much that you are not able to create the effect you want.
This screen will pop open when you select the MASK SELECTION button shown at #1 above. Slice the cursor over to make the desired selection. Then use you mouse to draw the mask area over your image. This will take just a small amount of practice.
We are now ready to create the mask effects described in our goals. The first mask is to increase the contrast in the blowing rain on the right center of the image. I have made a rather large mask to be sure to include all of the area I want to change. One possibility for the desired changes would be to move the Whites slider to the right and the Blacks slider to the left. With some experimenting and in combination with the contrast slider, this might work well.
Very often I will use the masks on masks, here referred to as Intersected Masks. If you place your mouse along the left side of the Mask 1 in this image, three dots will appear (yellow arrow points to the dots). By selecting those three dots, an additional drop down list will appear. I have selected Intersect Mask With. This opens up another drop down list. In this case, I have selected Luminance Range. Once that is done, an eyedropper appears. Select the lightest colors in the blowing rain.
This is the Luminance Range panel that shows up once you have selected a Luminance Range mask. The light vertical bars represent extremes of the predominant values in your radial filter. Place a cursor near the left bar and you will be able to slide it left or right. In this case, slide it to the right to reduce the number of darker values selected. You will see your mask overlay change when you do this. Slide it to position where just the brightest tones are selected for your mask.
If you don't want to adjust the brightest areas (the inversion layer clouds, which we will do in a separate step), grab the right vertical bar and slide it left to reduce their selection in the overlay.
Now that you have made these adjustments to the mask, you are ready to use the adjustments sliders. Try the Whites slider first. As soon as you move it, the overlay will disappear so you can see the effect. But the mask is still there and active. If the Whites slider is too effective, try the less sensitive Highlights slider.
Compare the windblown rain after our first masking action to our starting image.
In this image you can see the result of a mask applied to the sunlit plateaus in the lower center of the image. To accomplish this, I placed a radial filter over them, then intersected the mask with Color Range. Modifying with a color range mask is a little less predictable than modifying Luminance Range mask, but you are free to try this if you wish.
We are now ready to brighten the river. As we did before, use the Masking tool and a Radial filter. Drag it to a shape that includes all the light tones of the river. Then intersect the mask with the Luminance Range and adjust the left bar to the right until only the river is covered by the overlay. Lighten the river with the Whites or Highlights slider.
If you wish, you may also change the color of the river a bit (bluer or redder, say) by using the Color Temperature or Color Tint sliders.
You can see the brighter and slightly bluer river in the image below. Also note that a more complicated mask was emplyed to brighten the sun rays on the left side of the canyon. Because this involved separating the sky from the land, the mask was more complicated. Details on how this was done will be included in a later article.
Our final radial mask is used to brighten the inversion layer clouds. Repeat the steps we used for the rain. Again, make the clouds as bright as you can with retaining some detail. We want the clouds to demand attention and draw the viewer to the center of the image. To be sure you do not overdo it, keep an eye on the histogram at the top. If you see a red triangle (yellow arrow points to it), you have gone too far. Back off on the slider until the triangle turns black again and you will have it right.
The whites are slightly blown out as indicated by the triangle turning red (slightly blown out), yellow or white (very blown out). Note that the original RAW file had blacks blown out as indicated by the blue slider in the first image of this article. Adjustments were made to the blacks to correct this.
We have made substantial progress on this image. Once you are comfortable with masks, these steps would only take a few minutes. In the next article, we will continue with this image to demonstrate more complicated masks and the use of the recently added Object selection mask.