Lightroom 4.1 RC2: Artefacts when using shadows, clarity and image warp (lens corrections)

A very faint and "thin" version of the artefacts can be seen when no lens correction is applied at all. It can be seen most clearly at high contrast edges.

Here is an example (100% crop from a larger picture):

Image #1: Adobe defaults, no manual or profile lens corrections, no clarity.
Image #2: Plus clarity +100, you can see the faint "thin" artefacts already
Image #3: Plus manual lens correction rotation +0.1, the artefacts become "full-blown"

Applying lens profile corrections is producing very strange artifacts on some hard contrasty edges

This reply was created from a merged topic originally titled
Lightroom: Artifacts produced by lens profile correction tool.

Lightroom 4.1RC2 (Process version 2012)
As above, but there's more going on than just Lens Correction. Using just the Basic Panel for adjustments (everything else zeroed) there is still this hard edge high contrast artifact. Lens Correction certainly dramatically adds to the effect.

Adjust a photo using Process version 2010 then select Process version 2012
(Camera Calibration Panel.) Compare the high contrast edges in the same adjusted photo with Process version 2012 and Process version 2010.

I think you are seeing the difference between PV2010 's Develop settings and PV2012 "automatic" White and Black point settings. PV2012 shows more detail in the shadows and highlights, which is not a defect. It's just accentuating the lens defects.

Try this:

Adjust the image file using only PV2010 Basic controls and everything else turned off (zero'd as you say). Now create a virtual copy, change the copy to PV2012, and adjust the Basic controls so it looks as close as possible to the PV2010 image. When done the two Histograms should look virtually identical

Do you still this "hard edge high contrast artifact" in the PV2012 image with no other adjustments (i.e. No Lens Corrections tools) applied?

Thanks Todd.

I did as you suggested and experimented a bit. There was very little difference with the high contrast edges between PV2010 and PV2012 with or without Lens Corrections using a baseline image. But like LRusser24 I obtained similar results (I'll call it the barber pole effect) when applying Clarity with or without Lens Corrections (distortion and CR) applied.

Attached are two screen captures (100% crop in LR) including the settings panel.

Left is PV2012 w/Lens Correction/Clarity 0.
Right is PV2012 w/Lens Correction/Clarity 50.
Clarity set at 50 exaggerates the artifacts, but I was seeing those effects at Clarity 10.

As I already said:

I can see the same artifacts, but it only appears where there is chromatic aberration and/or fringing present in the image. It looks like Clarity is being applied to the image prior to CA and/or Defringe removal, because you can still see it with these two tools enabled. The high Clarity setting to seems to amplify the CA.

When LR builds the preview or export image it applies the Develop settings using several operations and several bitmaps, which are then merged to create the final processed output. What I think is happening is that the Clarity processing uses a bitmap that does NOT have any CA settings applied to it. This accentuates the CA (i.e. fringing), leaving halo like artifacts even after CA processing is applied.

LR3 'Fill' tool creates similar halo artifacts perhaps for the same reason, but we all assumed this was corrected in LR4.

LR 4.1 final and ACR 7.1 final: The "thick" artefacts when using lens corrections are gone, but the "thin" variant shown in my post above are still there. Note: The artefacts still change shape when changing lens correction parameters, but they always stay "thin".

I am slightly disappointed. However, the "thin" variant is probably visible only in 100% view on monitor. I am not sure whether it is visible in normal cases, e.g. prints.

This is a limitation of the current technology, a tradeoff we had to make to keep performance reasonable (otherwise to use the Highlights, Shadows, or Clarity sliders would be several times slower and use a lot more memory ...)

Thank you Eric, I understand and appreciate the tradeoff concerning maintaining LR's real-time operating performance (screen image building), but what about output image building?

Would it be possible to incorporate changes for better imaging during Export, Edit In, Print, and other output operations? I think most users wouldn't mind waiting a bit longer for their final output to be processed, especially to achieve the best results. I know this may cause complaints about screen imaging not matching the output, but we're talking very small artifacts. IMHO that is also a justifiable limitation of current technology “tradeoff" that most users would accept.

This is just a suggestion for improving an already outstanding product, my compliments to you and the rest of the LR team.

Hi Todd,

Indeed this is something we're considering. Thanks.

Eric

When activating lens profile correction and when i change my process from 2010 to 2012 and using the shadow recovery slider above +20 :
the black area close to white area are becoming jagged and stripped whithin the black area around the white
eg .A white texte on a black surface

My Camera is Nikon, and this apend for any camera i had



This reply was created from a merged topic originally titled
ACR: Jagged edge from process 2010 to 2012 with lens profile correction.

This issue is going to be hard to explain but I will give it a shot. I recently upgraded to Lightroom 4.3. After making adjustments to a photograph in Lightroom, I press CMD+E to open the photo in Photoshop. But when the photo opens, it has weird artifacts along the edges of the subjects within the photo. So, alternatively, I export the photo to my desktop and then open it with Photoshop. When it opens, the artifacts aren't there. The artifacts are only there when I use the 'Photo>Edit In' command within Lightroom. When viewing the photos in Lightroom, the artifacts are not present. I am using Lightroom 4.3, Camera Raw 7.3, and Photoshop CS5.1. The artifacts can be seen on the sleeve in the uploaded photo..

This reply was created from a merged topic originally titled
Weird Color Artifacts.