diggles
Well-known member
My first choice for photo editing is ACR/Photoshop. While looking for a way to apply LCC corrections without using C1/Phocus/Lightroom I ran across this article:
The steps outlined in the article do a good job of fixing vignetting, but didn't really help with colorcast. At first I was a bit frustrated, but then I wondered if this method could work to fix sensor tiling. I've tried it on 4 different images, 1 taken with the Digaron 28HR and 3 taken with the Digitar 43XL. Initial tests are quite promising.
Here are the steps I took with example images and screenshots:
STEP 1
RAW CAPTURE: Hasselblad CFV II 50C (cmos 50mp sensor), Digitar 43XL, and the WRS 1600 with 20mm of camera fall
RAW CAPTURE 100% Crop
As you can see this combo creates one hell of a mess. Tiling is very pronounced and streaky noise is noticeable in the sky.
Matching LCC Frame
STEP 2
Process files in Phocus and export 16bit tiffs to edit in Photoshop. With Phocus you are able to apply the LCC correction to the LCC reference file and export the corrected image as a 16bit tiff. This step is critical in making this work. Not sure it would work without having a corrected LCC reference file to work with. I'm not sure if Capture One or Lightroom allows you to export the corrected LCC reference file or not.
Corrected image using Scene Calibration in Phocus exported as 16bit tiff file
Corrected image 100% crop
Corrected LCC reference image
Phocus did a pretty good job of cleaning the image up. The extreme color cast is gone, but the sensor tiling and streaky noise is still present.
STEP 3
Create a photoshop file with the corrected image as the base layer. Add the corrected LCC reference image in a group above. Then create a Levels adjustment layer above the corrected LCC reference image. In the Levels control, hold down the option (alt on a PC) key and move the highlight (white) triangle slider left until you start to see highlights being clipped. The highlight triangle will end up being just to the right of the histogram mass.
Screenshot of the layer configuration and histogram
After making the levels adjustment, this is what the LCC reference image should look like
Step 4
Change the blending mode of the group with the LCC reference image and Levels adjustment layer to Divide and fine tune if needed.
Screenshot of blending mode changed to Divide
That's it. I'll add the final images + 100% crops in a follow up comment.
Note: With this image I did not need to fine tune the settings. With a different image I tested, there was still a faint outline of the tiling present after changing the blending mode to Divide. What I did to fix it is move the shadow (black) triangle in the levels control to the right until the tiling disappeared.
Vignetting 4: Photoshop Divide Layer
Vignetting 1: Overview Vignetting 2: Parametric Correction Vignetting 3: Correction Images Vignetting 4: Photoshop Divide Layer (this post) Vignetting 5: A Pathological Example Vignetting 6: Other …
pduncan.com
The steps outlined in the article do a good job of fixing vignetting, but didn't really help with colorcast. At first I was a bit frustrated, but then I wondered if this method could work to fix sensor tiling. I've tried it on 4 different images, 1 taken with the Digaron 28HR and 3 taken with the Digitar 43XL. Initial tests are quite promising.
Here are the steps I took with example images and screenshots:
STEP 1
RAW CAPTURE: Hasselblad CFV II 50C (cmos 50mp sensor), Digitar 43XL, and the WRS 1600 with 20mm of camera fall
RAW CAPTURE 100% Crop
As you can see this combo creates one hell of a mess. Tiling is very pronounced and streaky noise is noticeable in the sky.
Matching LCC Frame
STEP 2
Process files in Phocus and export 16bit tiffs to edit in Photoshop. With Phocus you are able to apply the LCC correction to the LCC reference file and export the corrected image as a 16bit tiff. This step is critical in making this work. Not sure it would work without having a corrected LCC reference file to work with. I'm not sure if Capture One or Lightroom allows you to export the corrected LCC reference file or not.
Corrected image using Scene Calibration in Phocus exported as 16bit tiff file
Corrected image 100% crop
Corrected LCC reference image
Phocus did a pretty good job of cleaning the image up. The extreme color cast is gone, but the sensor tiling and streaky noise is still present.
STEP 3
Create a photoshop file with the corrected image as the base layer. Add the corrected LCC reference image in a group above. Then create a Levels adjustment layer above the corrected LCC reference image. In the Levels control, hold down the option (alt on a PC) key and move the highlight (white) triangle slider left until you start to see highlights being clipped. The highlight triangle will end up being just to the right of the histogram mass.
Screenshot of the layer configuration and histogram
After making the levels adjustment, this is what the LCC reference image should look like
Step 4
Change the blending mode of the group with the LCC reference image and Levels adjustment layer to Divide and fine tune if needed.
Screenshot of blending mode changed to Divide
That's it. I'll add the final images + 100% crops in a follow up comment.
Note: With this image I did not need to fine tune the settings. With a different image I tested, there was still a faint outline of the tiling present after changing the blending mode to Divide. What I did to fix it is move the shadow (black) triangle in the levels control to the right until the tiling disappeared.
Last edited: