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Author Topic: RGB Channel Tone Curve Adjustments  (Read 3974 times)

ahbnyc

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RGB Channel Tone Curve Adjustments
« on: June 06, 2014, 11:58:03 pm »

After some fiddling around with LR4, I think I have basically figured out what adjustments to the separate color channel tone curves do, but I can't figure out how to use them in a useful way.  Can use of these curves make adjustments to colors in a more effective or efficient way than adjusting white balance or hue in the HSL panel, or provide better split tone adjustments to a black and white photo than using the split tone panel? Any tips or links to helpful articles would be much appreciated.
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luxborealis

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Re: RGB Channel Tone Curve Adjustments
« Reply #1 on: June 07, 2014, 08:09:41 am »

I don't use the Tone Curve as much as others but I find it immensely helpful when adjusting the colour of shadows. If my shadows are excessively blue, I'll select the bottom end of the blue channel line and drag it ever so slightly to correct the colour cast.
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David Eichler

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Re: RGB Channel Tone Curve Adjustments
« Reply #2 on: June 07, 2014, 01:03:43 pm »

I don't use the Tone Curve as much as others but I find it immensely helpful when adjusting the colour of shadows. If my shadows are excessively blue, I'll select the bottom end of the blue channel line and drag it ever so slightly to correct the colour cast.

I usually find it much more effective to do that with Photoshop, an HSL layer and masking.
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luxborealis

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Re: RGB Channel Tone Curve Adjustments
« Reply #3 on: June 07, 2014, 04:09:50 pm »

I usually find it much more effective to do that with Photoshop, an HSL layer and masking.

While it might make sense to use PS when exact colour accuracy is required (e.g. to match client colour specs) or when split colour temp lighting is used, I find that all of my landscape and nature images can be corrected using the LR Tone Curve. Besides, using the LR Tone Curve avoids creating a whopping big psd file in PS.
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PhotoEcosse

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Re: RGB Channel Tone Curve Adjustments
« Reply #4 on: June 07, 2014, 04:39:43 pm »

While it might make sense to use PS when exact colour accuracy is required (e.g. to match client colour specs) or when split colour temp lighting is used, I find that all of my landscape and nature images can be corrected using the LR Tone Curve. Besides, using the LR Tone Curve avoids creating a whopping big psd file in PS.

....and it is a 3-second job in LR but likely to take several minutes in PS.
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David Eichler

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Re: RGB Channel Tone Curve Adjustments
« Reply #5 on: June 07, 2014, 07:41:58 pm »

While it might make sense to use PS when exact colour accuracy is required (e.g. to match client colour specs) or when split colour temp lighting is used, I find that all of my landscape and nature images can be corrected using the LR Tone Curve. Besides, using the LR Tone Curve avoids creating a whopping big psd file in PS.

As an art photographer, you can choose exactly how you want to shoot and you can shoot to accommodate the processing and workflow you prefer. For commercial photography, I cannot afford to forgo the vastly greater array of processing capabilities that Photoshop offers-for its superior ability to solve technical problems and provide creative options-and I am certainly not going to let the size of a Tiff or PSD file get in the way of optimum results for what I need to do.
« Last Edit: June 07, 2014, 08:22:58 pm by David Eichler »
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Tim Lookingbill

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Re: RGB Channel Tone Curve Adjustments
« Reply #6 on: June 08, 2014, 04:55:59 pm »

As an art photographer, you can choose exactly how you want to shoot and you can shoot to accommodate the processing and workflow you prefer. For commercial photography, I cannot afford to forgo the vastly greater array of processing capabilities that Photoshop offers-for its superior ability to solve technical problems and provide creative options-and I am certainly not going to let the size of a Tiff or PSD file get in the way of optimum results for what I need to do.


It shows in your work, David. Just looked at your site for the first time. Glad I did.

Sweetest looking interior/exterior architectural renderings I've ever seen even with the sharpening halos. The most tasteful HDR tone mapping I've seen lately. I assume you used layer masking techniques to get the halo-less clarity on all the flat surfaces along with good lighting. I bet shadows taper and smooth out nicely on a commercial press using perceptual rendering intent.
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ahbnyc

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Re: RGB Channel Tone Curve Adjustments
« Reply #7 on: June 09, 2014, 11:13:54 pm »

Thanks for the responses!
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David Eichler

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Re: RGB Channel Tone Curve Adjustments
« Reply #8 on: June 10, 2014, 02:12:19 pm »

It shows in your work, David. Just looked at your site for the first time. Glad I did.

Sweetest looking interior/exterior architectural renderings I've ever seen even with the sharpening halos. The most tasteful HDR tone mapping I've seen lately. I assume you used layer masking techniques to get the halo-less clarity on all the flat surfaces along with good lighting. I bet shadows taper and smooth out nicely on a commercial press using perceptual rendering intent.

Thanks, Tim. However, I did not use any HDR/tonemapping for any of the images there. I did use exposure fusion for a couple of interior images, which some people classify as HDR, but that is it. I do often use multiple exposures for contrast control (among many other things), but that is with Photoshop masking and layering, often combined with supplementary lighting for the interiors (and sometimes the exteriors).
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SangRaal

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Re: RGB Channel Tone Curve Adjustments
« Reply #9 on: June 13, 2014, 12:59:01 pm »

During may of this year X-Rite had an interesting webinar by Marc Muench re: using tone mapping in LightRoom as the basic work flow(up in their archives). His basic technique involves removing the chroma by desaturating the image and using RGB tone curves to get the contrast correct, and then using clarity plus filters and only then bringing back color to finish his work flow(this is a simplification of his work flow}. I thought this method was interesting he had developed this alternative method working om film scans in early photoshop lab space.
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