Artifacts in bokeh when using HDR in lightroom CC

  • 1
  • Problem
  • Updated 3 years ago
When I merge HDR photos with a low depth of field, there's a lot of artifacts between highlights and shadows. See example:

It would be great to get this fixed in the next update, thanks!



Ryan
Photo of Ryan Filgas

Ryan Filgas

  • 14 Posts
  • 0 Reply Likes
  • bummed

Posted 3 years ago

  • 1
Photo of Steve Sprengel

Steve Sprengel, Champion

  • 2611 Posts
  • 333 Reply Likes
Can you provide your originals? Use www.dropbox.com and post a public share link, here.
Photo of Ryan Filgas

Ryan Filgas

  • 14 Posts
  • 0 Reply Likes
Here's a link, it might take a while to upload though.

https://www.dropbox.com/sh/oakwtvpyl9...
Photo of Ryan Filgas

Ryan Filgas

  • 14 Posts
  • 0 Reply Likes
They're fully uploaded, have at it.
Photo of Ryan Filgas

Ryan Filgas

  • 14 Posts
  • 0 Reply Likes
Does anybody else have this problem?
Photo of Steve Sprengel

Steve Sprengel, Champion

  • 2611 Posts
  • 333 Reply Likes
If you click between the various images you'll see that the problem is parallax due to relative subject motion between the foreground trees and the background trees from one image to the next--temporal artifacts. The bug is in the image acquisition or user expectations, not the HDR processing.

The same thing would happen with an HDR of a street scene where people are moving from one source image to the next.

The solution is to turn on Deghosting. Normally (with Deghosting off) HDR will arithmetically combine the pixel values of all the images together to create a single value from the values of that same position in all the source images and if everything is perfectly aligned amongst the source images the result will be ok, but if there is relative motion, you'll see the halos and other odd artifacts because you have a background pixel in one of the source images and a subject pixel from another, or in your situation different colored leaves and even sky sharing the same pixel position across the source images.

With Deghosting on the HDR process looks for areas where there is relative motion between one image and the other and instead of combining all the source images pixels, it will choose pixels from only one source image or another and then dim or brighten that pixel to match the ones from where it can combine all the image pixels together.

The tradeoff will be that because a single layer's pixels are used and those pixels might be brightened, the noise can increase in parts of the image.

Here is a screenshot of the same area of the image in your first post but with Deghosting turned on and there are no halos but some noise:
Photo of Ryan Filgas

Ryan Filgas

  • 14 Posts
  • 0 Reply Likes
Great to know, thank you!