Luminous Landscape Forum
Raw & Post Processing, Printing => Digital Image Processing => Topic started by: The View on April 20, 2008, 08:50:31 pm
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I have seen images I admire for their rich, deep blacks, while the rest of the image seems to have normal tone values.
If, for example, I lower the shadow values in Camera Raw, the contrast automatically increases.
I wonder if there could be a threshold, that deepens the tones, and leaves the rest of the image alone.
Sorry that I can't describe it better at the moment...
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That would be the Curve control in ACR or Photoshop...
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I do it that way in camera raw.
But lowering the shadow values automatically somehow increases the contrast in the rest of the picture, also in the areas that are brighter.
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I do it that way in camera raw.
I'd say do it afterwards - try looking at the effects of different shaped curves in an adjustment layer. There are lots of different techniques, but they invariably do it -after- the raw conversion. ACR is for me the way of getting the best material to work on in PS. I do use ACR corrections quite a bit when I'm converting a batch of images for a commercial job, but if it's individual images (for prints say) then most the work gets done after the conversion
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But lowering the shadow values automatically somehow increases the contrast in the rest of the picture, also in the areas that are brighter.
If you want black blacks and white whites, then increasing global contrast is unavoidable. You can decrease local contrast by doing a Gaussian Blur with a 10-50 pixel radius and the opacity faded to taste.
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Try selecting luminosity (mac: Command+Option+~ (tilde) PC: Control+Alt+~). After you do that do an inversion of the selection (Command + Shift + "i" ).
At that point you'll have a selection of the darker stuff in your image..mid tones on down to black.
This makes it easier to lock down your brighter tones on a curve so you can darken the stuff you want dark. The great thing is that you are allowed to do other stuff while in this selection, OMG.
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Try selecting luminosity (mac: Command+Option+~ (tilde) PC: Control+Alt+~). After you do that do an inversion of the selection (Command + Shift + "i" ).
At that point you'll have a selection of the darker stuff in your image..mid tones on down to black.
This makes it easier to lock down your brighter tones on a curve so you can darken the stuff you want dark. The great thing is that you are allowed to do other stuff while in this selection, OMG.
[a href=\"index.php?act=findpost&pid=190961\"][{POST_SNAPBACK}][/a]
This sounds interesting.
I'll give this a try.
Thanks.
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If you want black blacks and white whites, then increasing global contrast is unavoidable. You can decrease local contrast by doing a Gaussian Blur with a 10-50 pixel radius and the opacity faded to taste.
[a href=\"index.php?act=findpost&pid=190944\"][{POST_SNAPBACK}][/a]
I guess the problem is the local contrast.
It completely ruins the smoothness of the image tone. As if the image would break up, and it loses its - how shall I put it - its luminous character.
I hope this indicates what I'm fighting with...
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I'd say do it afterwards - try looking at the effects of different shaped curves in an adjustment layer. There are lots of different techniques, but they invariably do it -after- the raw conversion. ACR is for me the way of getting the best material to work on in PS. I do use ACR corrections quite a bit when I'm converting a batch of images for a commercial job, but if it's individual images (for prints say) then most the work gets done after the conversion
[a href=\"index.php?act=findpost&pid=190919\"][{POST_SNAPBACK}][/a]
Why is it not a good process to do "curves" in Camera Raw?
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Why is it not a good process to do "curves" in Camera Raw?
It IS good practice, at least for global luminance adjustments. The PS tool has more options than the one in ACR, but there's no good reason not to do what you can in ACR.
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I have been doing it all the time and not noticed any problems...
... except in images with higher... well, in black and white negatives I'd have said "density", then things get rough, like when you pull the black slider too much to the right.
It then works better to do it in curves. Don't know why, is a result of experience.
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Actuall, in this situation, View is better off going for reasonable blacks with as much detail as possible in them in ACR, or whatever raw tool he's on. Then he can go into Photoshop and use the various tools that allow more specific editing on his blacks. You do tend to sacrifice detail when you go for those crispy blacks and ACR doesn't really give you the type of specific control that you can get in PS. Sometimes you need to just render a generally decent and open file in RAW and know that PS is going to be used for the nitty.
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Actuall, in this situation, View is better off going for reasonable blacks with as much detail as possible in them in ACR, or whatever raw tool he's on. Then he can go into Photoshop and use the various tools that allow more specific editing on his blacks. You do tend to sacrifice detail when you go for those crispy blacks and ACR doesn't really give you the type of specific control that you can get in PS. Sometimes you need to just render a generally decent and open file in RAW and know that PS is going to be used for the nitty.
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Yes, I found that out. Leaving blacks conservative, even if the image is too flat for my taste.
Looks like ACR has its limits there.
What process do you have in mind for enriching blacks?
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Yes, I found that out. Leaving blacks conservative, even if the image is too flat for my taste.
Looks like ACR has its limits there.
What process do you have in mind for enriching blacks?
[a href=\"index.php?act=findpost&pid=191343\"][{POST_SNAPBACK}][/a]
In PS try steepening the curve in curves till you get the blacks and whites as you want them That will make the midtones too contrasty Then another layer that decreases the contrast overall till the mid tones look like you want them and use the blend if sliders to target the midtones leaving the blacks and whites contrasty It could be used to target blacks only and whites only seperately Do a search for blend if in layers if you don't know how to use it Worthwhile
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A curve similar to the following, makes dark tones darker,
I don't know if you can reproduce it in cameraraw.
Jacopo
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A curve similar to the following, makes dark tones darker,
I don't know if you can reproduce it in cameraraw.
Yes, you can.
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In PS try steepening the curve in curves till you get the blacks and whites as you want them That will make the midtones too contrasty Then another layer that decreases the contrast overall till the mid tones look like you want them and use the blend if sliders to target the midtones leaving the blacks and whites contrasty It could be used to target blacks only and whites only seperately Do a search for blend if in layers if you don't know how to use it Worthwhile
[a href=\"index.php?act=findpost&pid=191384\"][{POST_SNAPBACK}][/a]
This sounds very interesting.
I haven't done any blending of two curves adjustments. At the moment I'm a bit puzzled, who you can have steep contrast in the midtones in your first adjustment (that gives great whites and blacks), and then a second adjustment that only softens the midtones.
Did I repeat that right? Why does the blending only affect the midtones?
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A curve similar to the following, makes dark tones darker,
I don't know if you can reproduce it in cameraraw.
Jacopo
[a href=\"index.php?act=findpost&pid=191392\"][{POST_SNAPBACK}][/a]
Thanks!
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This sounds very interesting.
I haven't done any blending of two curves adjustments. At the moment I'm a bit puzzled, who you can have steep contrast in the midtones in your first adjustment (that gives great whites and blacks), and then a second adjustment that only softens the midtones.
Did I repeat that right? Why does the blending only affect the midtones?
[a href=\"index.php?act=findpost&pid=191434\"][{POST_SNAPBACK}][/a]
On the second layer which is the one where the mid tones look OK to you the Blend if targets the mid tones and excludes the darkest tones and the lightest tones The darkest and lightest tones show through from the underlying layer If you understand how Blend if works then you will realise how it is done A few weeks ago there was a long thread on Blend if It is a little understood method that deserves more use Google for it and make it part of your workflow It can be used in all sorts of situations including sharpening
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That would be the Curve control in ACR or Photoshop...
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Yes. Curves in Photoshop is one way. My TLR Tone Enhance action set includes a Punch Blacks action. It uses a Curves adjustment layer to boost the blacks.
[a href=\"http://www.thelightsrightstudio.com/TLRToneEnhance.htm]http://www.thelightsrightstudio.com/TLRToneEnhance.htm[/url]
My action goes right up the diagonal line and pins the curve at (75, 75), (100, 100), (125, 125), (150, 150), (175, 175), (200, 200), (225, 225). That keeps the curve above the black punch from shifting. Then it pulls the curve down so Input = 30 and Output = 15.
Be sure to set the Blend Mode to Luminosity to avoid color shifts in the shadows with this maneuver.
In ACR 4, you might consider the Blacks slider. It is the RAW equivalent of the Levels slider in Photoshop. Better would be to apply a Point Curve. You could add the points I mention and save your own preset in just a couple of minutes.
Send me an e-mail or a Yahoo IM (gmitchel850) and I'll send you the .XMP file for an ACR preset that's the equivalent of the Curve setting from my TLR Punch Blacks action. Or a Lightroom preset, if you prefer.
Cheers,
Mitch
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On the second layer which is the one where the mid tones look OK to you the Blend if targets the mid tones and excludes the darkest tones and the lightest tones The darkest and lightest tones show through from the underlying layer If you understand how Blend if works then you will realise how it is done A few weeks ago there was a long thread on Blend if It is a little understood method that deserves more use Google for it and make it part of your workflow It can be used in all sorts of situations including sharpening
[a href=\"index.php?act=findpost&pid=191584\"][{POST_SNAPBACK}][/a]
I don't claim to have discovered this method It was a thought that popped into my head when I read the thread I am pretty sure that Dan Margulis will have something on it in his books I have just experimented with four or five images Ones where they were flat looking especially the mid tones When using the Blend If make sure that the slider points are split Like everything else a little experimentation is a must
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When I have a photo worth my time, the only way to get what I want is to use local adjustments. One pretty cool way (although a bit tedious) is to "develop" the RAW image in ACR several different ways, one for each aspect of the photo, and opening each of these into PS. Then, just drag and drop the layers into one file, close all the rest, and attach masks to all but the background layer. Use a brush set to hardness of "0" and paint on or off the masks where you want each of the layers to shine through. I think this gives a file that is more "robust", that is, less likely to posturize when applying global adjustments to the stack of layers. Anyway, it's pretty simple, and it works for me.
John
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one easy way to deepen the blacks without touching the mids would be with selective color:
select blacks and then boost the black channel.
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one easy way to deepen the blacks without touching the mids would be with selective color:
select blacks and then boost the black channel.
This is only useful if editing in CMYK mode, which is pointless 99% of the time.
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This is only useful if editing in CMYK mode, which is pointless 99% of the time.
[a href=\"index.php?act=findpost&pid=191733\"][{POST_SNAPBACK}][/a]
I have used selective color to improve skin tones and must say I got good results out of it, especially with the blacks and neutral channel.
Why do you think it would only be applicable to CMYK?
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I have seen images I admire for their rich, deep blacks, while the rest of the image seems to have normal tone values.
If, for example, I lower the shadow values in Camera Raw, the contrast automatically increases.
I wonder if there could be a threshold, that deepens the tones, and leaves the rest of the image alone.
Sorry that I can't describe it better at the moment...
[a href=\"index.php?act=findpost&pid=190871\"][{POST_SNAPBACK}][/a]
Since I own PixelGenius' PhotoKit I just use the "Punch Black" from the "Tone Correction Set". It creates a layer so its easy to tune to taste.
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I have used selective color to improve skin tones and must say I got good results out of it, especially with the blacks and neutral channel.
Why do you think it would only be applicable to CMYK?
[a href=\"index.php?act=findpost&pid=191789\"][{POST_SNAPBACK}][/a]
Selective Color works with RGB images.
You get more control with Curves. Selective Color, especially if you choose Absolute instead of Relative, will stop up the shadows quickly.
You can punch your blacks and still retain shadows detail with Curves.
More important, however, was that the original post asked about being able to punch up the blacks in ACR. There are multiple ways to do it in Photoshop, including Selective Color. ACR is more limited in its ability to punch the blacks.
Cheers,
Mitch
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I have seen images I admire for their rich, deep blacks, while the rest of the image seems to have normal tone values.
If, for example, I lower the shadow values in Camera Raw, the contrast automatically increases.
I wonder if there could be a threshold, that deepens the tones, and leaves the rest of the image alone.
[a href=\"index.php?act=findpost&pid=190871\"][{POST_SNAPBACK}][/a]
Not sure if it was already suggested.
You could combine Local contrast enhancement with Blend-if control.
For example:
/> on a duplicated or merged image layer, apply USM with something like Strength 20, Radius 50.
/> Blend mode set to Luminosity, Opacity perhaps a bit reduced to 80%
/> Layer style > Blend-if > This layer > white triangle split to 0/64
Given that Clarity in ACR is focused on the midtones, this may be a nice after-treatment in Photoshop when needed. It doesn’t seem to eat up the shadow details, or increase global contrast, while the blacks are getting deeper as long as such dark areas don’t stretch beyond the USM radius. Whereas I’d be careful with Curves which as a matter of principle always do both: they increase the contrast for some tones while decreasing it for others (local slope >/< 1).
Peter
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A quicklook at this thread indicated not much attention to printing.
A higher resolution eg on Epson 2880 dpi rather han 1440 , puts down more ink thus deepening blacks. Relative Colorimetric rendering usually gives deeper shadows than perceptual.
Use of polarising filters when making profiles expands deep colour rendering giving shadow richness. The smoother the paper the deeper the blacks.
HTH
Brian
www.pharoseditions.com.au
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This is only useful if editing in CMYK mode, which is pointless 99% of the time.
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huh? it works well in rgb.
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How the hell do you boost the BLACK CHANNEL in RGB mode???
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How the hell do you boost the BLACK CHANNEL in RGB mode???
[a href=\"index.php?act=findpost&pid=192025\"][{POST_SNAPBACK}][/a]
via Selective Color > Colors: Blacks > Black slider
Peter
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via Selective Color > Colors: Blacks > Black slider
Peter
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That's not a channel.
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That's not a channel.
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... per color range selection (in this case: Blacks), well – I would have thought it is a CMYK channel control.
Peter
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via Selective Color > Colors: Blacks > Black slider
which isn't the same as "boosting the black channel"...
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which isn't the same as "boosting the black channel"...
[a href=\"index.php?act=findpost&pid=192110\"][{POST_SNAPBACK}][/a]
C'mon now, Jonathan. It was obvious that the intended advice was to boost the blacks via the Selective Color command. That is a technique that will work, if used with care.
You never clarified that you understood the point about using Selective Color. The most charitable interpretation is that you were only quibbling over the reference to boosting the "black channel" as opposed to boosting the blacks in the photo via Selective Color.
You might want to consider that Selective Color uses CMYK colors to correct the image.
A couple of quotations from the Adobe Photoshop Help File might help inform this discussion:
"Even though Selective Color uses CMYK colors to correct an image, you can use it on RGB images."
"For example, you can use selective color correction to dramatically decrease the cyan in the green component of an image while leaving the cyan in the blue component unaltered."
IOW, discussion of the Black channel is not irrelevant with respect to discussion of Selective Color.
Back to your point . . .
which isn't the same as "boosting the black channel"...
[a href=\"index.php?act=findpost&pid=192110\"][{POST_SNAPBACK}][/a]
The recommendation was to boost the Black component for Blacks with Selective Color. That is pretty much the same as boosting the Black channel.
That misstatement was more helpful, in terms of giving the original poster a technique to use, than the quibble over boosting the Black channel v. boosting the blacks.
Cheers,
Mitch
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C'mon now, Jonathan. It was obvious that the intended advice was to boost the blacks via the Selective Color command. That is a technique that will work, if used with care.
You never clarified that you understood the point about using Selective Color. The most charitable interpretation is that you were only quibbling over the reference to boosting the "black channel" as opposed to boosting the blacks in the photo via Selective Color.
The original comment was unclear; it would have been much better written as "increasing the black slider setting in the Selective Color dialog" instead of "boosting the black channel".
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The original comment was unclear; it would have been much better written as "increasing the black slider setting in the Selective Color dialog" instead of "boosting the black channel".
[a href=\"index.php?act=findpost&pid=192147\"][{POST_SNAPBACK}][/a]
Agreed, that would have been more accurate. You could have gotten agreement on that point without snapping at someone who was trying to be helpful, "How the hell . . ."
Cheers,
Mitch
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I stand corrected.
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I am new to PS but in one of the Print tutorials, Jeff "punched the blacks by, I believe, making a selection of the "blacks" and then resetting those pixels to 0.
Steve
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I am new to PS but in one of the Print tutorials, Jeff "punched the blacks by, I believe, making a selection of the "blacks" and then resetting those pixels to 0.
[a href=\"index.php?act=findpost&pid=192365\"][{POST_SNAPBACK}][/a]
Actually i think I used Color Range to select Blacks with a fuzziness of about 40 (I can't remember the number) and either, popped to a new layer set to multiply blend or popped a new Levels adjustment layer where I moved the black clip to 10 or so. Just so you know, they will both do something similar, make the darkest tones that aren't black, closer to black–selectively.
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Selective Color works with RGB images.
You get more control with Curves. Selective Color, especially if you choose Absolute instead of Relative, will stop up the shadows quickly.
You can punch your blacks and still retain shadows detail with Curves.
More important, however, was that the original post asked about being able to punch up the blacks in ACR. There are multiple ways to do it in Photoshop, including Selective Color. ACR is more limited in its ability to punch the blacks.
Cheers,
Mitch
[a href=\"index.php?act=findpost&pid=191838\"][{POST_SNAPBACK}][/a]
I very much appreciate all the valuable tips and comments!
I actually used the Camera Raw example to describe the problem I was working on.
It was clear to me that the solution had to be done in Photoshop, and I appreciate everybody's very valuable comments.
The reason why I currently use selective color a lot is, that I started out with Lightroom, and got to Photoshop only later.
Mitch, I particularly appreciate that comment about being able to retain more details in shadows when using curves compared to using selective color.
My process is currently using levels first to optimize the "reach" of the histogram, then go to curves to get contrast and exposure in different parts of the images better, and then fade using luminosity blend mode. Then Hue/saturation, after this I go to selective color.
I currently use curves rather conservatively, still gaining experience.
When I get the image back into Lightroom, I can still boost the black slider a bit, and reduce the shadow value. This adds more to the DEPTH OF SHADOWS that I am looking for.
This is my current process (not mentioning sharpening at the end), comments apprciated.
I found that tip with the color range command and the change of the pixel values very interesting.
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Mitch, I particularly appreciate that comment about being able to retain more details in shadows when using curves compared to using selective color.
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I'm pleased I could help.
You can do the curve to punch blacks in Lightroom.
Just be careful. Inside Photoshop, you can use Blend If settings to protect the extreme shadows when you punch the blacks with a Curves adjustment. With LR or ACR, you don't have that protection. You can inadvertently clip the shadows with a Curves adjustment.
Send me an IM with an e-mail address, and I'll gladly give you a LR preset. I can give you one to punch the whites, too.
I hide in public. LOL. So it's easy to find my e-mail @ The Light's Right. But I don't like posting it in forums. I get enough spam already. (No good deed goes unpunished. LOL)
Cheers,
Mitch
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I guess the problem is the local contrast.
It completely ruins the smoothness of the image tone. As if the image would break up, and it loses its - how shall I put it - its luminous character
If you want to make black dark tones, you increase the contrast near the dark tones.
The curve I suggested has 3 zones. Just to make it more clear, let me fix some numbers:
- the first zone (the flat one) ending point is at x=16
- the second zone (the curve to go from the y=0 segment to the y=x segment) ending point is at x=32
- the third zone (the y=x segment) starts from x=32 and goes uo to x=255
What is the effect of this curve on the image luminosity ?
- (first zone) if the luminosity of a pixel is less or equal to 16, the luminosity is setted to 0
- (second zone) if the luminosity of a pixel is in (16,32) range the luminosity is decreased following the curve
- (third zone) if the luminosity of a pixel is greater than 32 it is untouched
Suppose in your image you have a pixel with luminosity = 15 and a near pixel with luminosity = 35.
In this case the gradient is (35-15)=20.
Whe you apply the curve the resulting gradient will be (35-0)=35.
You have more contrast, but this is exactly what you want.
Changing the values, you can get a different effect.
The smoothness of the image tone may be more or less preserved increasing the second zone going gently from y=0 segment to y=x segment.
If you extend the second zone, you have a smoother increase of the contrast, but more tones are affected. Of course.
You have to tweak the values depending on image.
Remember that a curve is a tonal adjustment that works for all the image, unless you apply it selectively.
Jacopo