How to Use The ‘Cookie Cutter’ Approach to Extending Dynamic Range
This is a pretty cool technique for those needing to extend image latitude or dynamic range. I tried it on several images and it worked well on some and not at all on others. It is certainly worth a try before moving on to HDR or other methods.
This technique is from Ellon Anon’s great book: Photoshop for Nature Photographers and its titled: The Cookbook Approach to Expanding Latitude. This is a very good book by the way, specifically aimed at nature photographers and you can buy it here.
To start, open two images in Photoshop, a dark one which has the perfect exposure for the sky or clouds or any areas that are important. Then open the bright one image which has detail for areas that were to dark in the other image.
I opened these two images from Arches National Park: one is the main exposure which has good detail throughout and is what could be considered the perfect exposure for the image. The second image is for the shadow areas and is a good exposure for those areas. There is a two stop difference between the two images: 1/8th second and 1/30 second.
With both images open, follow these steps:
- Using the Move Tool in PS and holding down the Shift key, drag the darker image on top of the lighter image. Holding the shift key keeps both images in perfect registration.
- Next, add a layer mask to the top/darker image.
- Select the background image by clicking on the image then Ctrl/Cmd: click to select the entire image.
- Now hit Ctrl/Cmd-C to copy the selection to the clipboard.
- Highlight the darker layer and then hold Alt/Option and click on the mask. This makes the mask appear over the image.
- Hit Ctrl/Cmd-V and the contents are pasted into the mask creating a contrast mask.
- Now click on the contrast mask and it will return to the main image and shows a reduction in contrast.
- Next, apply a Gaussian Blur to the contrast mask to allow the images to blend for a natural look. (Results of my blending are below.)
- Based on how blur is applied and the resulting contrast, you may want to apply a Curves Adjustment Layer to enhance contrast.
Here are my screen captures showing each step:
The dark and light original images.
Then highlight the background image, Select All, and Copy.
Click the layer mask again and you return to the image.
Here is the image after dynamic range has been extended. It lacks contrast.
This image sets the Gaussian Blur to 5 and it helped contrast slightly.
Here I increased the blur to 20 and the halos are starting to really show.
This image has Gaussian Blur all the way at 250. Contrast is much better but the halos are so large it looks like a bad burn and dodge effort.
So I reset the blur to 5 since anything higher began the create the halos. Next I added a Curves Adjustment Layer and tweaked contrast that way.
So here is the final image. Two images with a two stop difference in exposure. Gaussian Blur set to 5 and a Curves layer to add contrast.
I have also tried a few other images that are completely different and was able to go much higher on the blur to find the right amount of contrast. Below is a coastal lighthouse where the blur was set at 27 and it brought in the sky nicely without adding halos.
This is a pretty effective technique that will work on some images and may not on others which illustrates the point that there are a million ways to do one thing on Photoshop.
Have any thought? Please leave a comment.
Ellon Anon’s Book: Photoshop for Nature Photographers.