Hello
I experimented with contrast pinning and definitely can see that it will be very useful in correcting images. I experimented with contrast pinning in both RGB and Lab modes. I really do not like the results and would like your input so I can re-try them. Also, can you send a curve file so I can see the exact curves you created to correct this image.
Thank you
David
CM Week 4 Example 1 - Dog
David,
First of all you added contrast to the image and that is the bottom line.
Contrast pinning in RGB is a bit tougher to master so let's start with LAB.
In Shot3 I am picking a part of the dog that gives me the longest "color worm" to work with. If I enhance the contrast across too little of a range the image tends to be harsh...I want to spread the correction out a bit. The trouble with RGB and contrast pins is the color cast you can introduce by changing any single channel.
In Shot4 I have selected my range and made the contrast adjustment to make the dog look sharper...BUT only in the L channel. Adjusting the color channels just makes this harder to complete.
In shot5 I am making the image color look better with a few simple Adjustments to the A and B curves. The tip off is the lighter fur patch in the front of the dog.. It should be yelloow or white...not green.
Greg
First of all you added contrast to the image and that is the bottom line.
Contrast pinning in RGB is a bit tougher to master so let's start with LAB.
In Shot3 I am picking a part of the dog that gives me the longest "color worm" to work with. If I enhance the contrast across too little of a range the image tends to be harsh...I want to spread the correction out a bit. The trouble with RGB and contrast pins is the color cast you can introduce by changing any single channel.
In Shot4 I have selected my range and made the contrast adjustment to make the dog look sharper...BUT only in the L channel. Adjusting the color channels just makes this harder to complete.
In shot5 I am making the image color look better with a few simple Adjustments to the A and B curves. The tip off is the lighter fur patch in the front of the dog.. It should be yelloow or white...not green.
Greg
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Hello.
I am running into another medical problem. My left leg is swollen, red and starting to bluster so I have to keep in elevated. It was elevated all day yesterday and most of today. I am hoping to do some work today and tomorrow before I have to elevate the leg again.
My question is more of a theoretical one. In the examples you posted the grass looks significantly different in each example, however, the grass in each image still looks realistic. The same is true of the dog. This seems to indicate that there are many different corrections that make the image look better but only one that realistically portrays the actual scene that the digital camera was used on. I suspect their is no algorithm or procedure for finding the theoretical correct photo so some knowledge is needed of the scene prior to using the digital camera to take the photo. What is your opinion on this situation?
I decided do re-try the dog example. What do you think of this correction?
Thank you
David
I am running into another medical problem. My left leg is swollen, red and starting to bluster so I have to keep in elevated. It was elevated all day yesterday and most of today. I am hoping to do some work today and tomorrow before I have to elevate the leg again.
My question is more of a theoretical one. In the examples you posted the grass looks significantly different in each example, however, the grass in each image still looks realistic. The same is true of the dog. This seems to indicate that there are many different corrections that make the image look better but only one that realistically portrays the actual scene that the digital camera was used on. I suspect their is no algorithm or procedure for finding the theoretical correct photo so some knowledge is needed of the scene prior to using the digital camera to take the photo. What is your opinion on this situation?
I decided do re-try the dog example. What do you think of this correction?
Thank you
David
- Attachments
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- 20110120_example1-lab2screenshot-jpg (235.95 KiB) Viewed 6137 times
The reason for the grass changing color is that I made all the tonal and contrast corrections first in LAB...
As you do that the image will lose saturation a bit as you change the brightness of the image. The first correction set the shadow and highlight.
The second adjusted the contrast....
By the time those two were done the saturation took a beating...In shot 3 I added the color back and tweaked it a bit to make the fur in the front of the dog look less green.
In your images the dog has a greenish cast and you really need to be aware of that when you work on hair...
Greg
As you do that the image will lose saturation a bit as you change the brightness of the image. The first correction set the shadow and highlight.
The second adjusted the contrast....
By the time those two were done the saturation took a beating...In shot 3 I added the color back and tweaked it a bit to make the fur in the front of the dog look less green.
In your images the dog has a greenish cast and you really need to be aware of that when you work on hair...
Greg
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