Make an Adjustment Layer, either Hue & Saturation or Channel Mixer with Monochrome checked. The color info is still there. You can show it by painting with Black on the Mask and it’s non-destructive unlike the methods you mentioned.
Simply desaturating an RGB image completely destroys the tonal relationship between the colours, as you can see below. (try it for yourself by downloading this image). Converting to Greyscale preserves the tones.
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.. However: because greyscale is a single channel you lose a huge chunk of image data – and the more you edit (even a simple Levels adjustment) the more the image will degrade.
Here’s a better way:
First add two Hue/Sat adjustment layers as shown below. Name the top layer to "Film" and slide the "Saturation" to zero. Then set the one directly above the image layer to "Colour" mode and the set Hue slider to +82. Call this layer "filter".
As you can see the colour bar at the top has been converted to black and white whilst retaining the tonal relationships.
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Now comes the fun part:
Open the "filter" layer and move the Hue slider. See how easy it is to fine tune the tones? The "filter" layer is like having a continuously variable filter on a camera loaded with B&W film. The creative posibilities are endless.
Enjoy.
Chris.
Chris,
Really cool, I might just change the way I convert to B&W to this. (some experimentation is in order first)
I agree. nicely done chris!
But, what about Channel Mixer…which gives you control over the channels even in Monochrome.
Hi,
I know of several way to do this in PS,
-Reduce saturation to 0, convert to grayscale, convert to lab & creating new image from grayscale channel, playing with individual rgb channels which one of the above / are there any better ones best serve my purpose?
If all you want is to quickly see how your image looks in B/W/grayscale, then you can quickly create a Hue/Saturation layer and just drop the saturation to 0.
For the photos I’ve converted to B/W I have found that what method I use depends a lot on the photo. However just to see how your current image looks in B/W, I find that quickly adding a h/s layer and drop the saturation to 0 gives a pretty good idea of how the image would look like without colors.
If you find that you use a specific method all the time, then what I would do is create an action that duplicates the current image and automatically applies the method that you want. This way you can quickly see how your image will look like after you apply your favourite methods to it. —
Arnor Baldvinsson
San Antonio, Texas
Channel mixer is good for basic tonal control but is clumsy to use. The Hue/Sat method is more intuitive.
The other nice thing about the Hue/Sat layers method is that it allows you to target specific colour ranges.
Picture this scene for instance: Green grass, Red car, blue sky with white fluffy clouds.
To darken the sky using B&W film you would place a Red filter over the lens. Both the Hue/Sat and Channel Mixer methods can emulate this. Snag is – whilst darkening the sky, you also lighten the car!
The solution is to target just the Blues in the scene by selecting "Blues" from the Hue/Sat’s drop down menu. Now you can darken the sky without altering the tonal values of the car!
But it doesn’t stop there! Standing by the car is a lady wearing a blue sweater. Darkening the sky has also darkened the sweater! However, because the Hue/Sat layer has a layer mask, it is easy to simply "paint out" the filtration locally to restore the paler tones of the sweater.
It really is the best thing since sliced bread. 🙂
Chris.
Chris,
Perfect!
I have read many sophisticated ways to do this job but yours is the best ever! Thanks a lot for sharing!
Ronald
This is asked enough that maybe it should be added to the FAQs for quick reference.
hey guys,
thanks for the help and links.
There is something else i would like to ask you guys about.
Is there anyway to see from a photo the absolute relationship of how Light (through value relationships depicting shadow,shade,direct light) shining on a scene affects when viewing the image in B&W? ( i mean hsV/Lab numerical differences not how it appear on monitors)
i.e. say i have a cube which i know is of a certain Local H,s,b value in a certain lighting condition. then when I shine an extra spotlight on it, i take another picture of it then compare the h,s,b values of both pictures, then i would know how the spot light have added brightened up the various areas. I’m more interested in only the amount of light(lghtness/darkness changed) than the exact hsb value.
1. I’m aware the color of spotlight etc all affects. but if i just require a rough estimation, which method is most suitable?
2. I was wondering does reducing the amount of Saturation/creating a grayscale from the ‘L’ channel of LAB achieve that ? so i can compare the amount of lightness/darkness only.
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If now, i were to just take any photograph and convert it to B&W, is it possible to accurately see how light affects it?(because shapes have form, i can identify through the obtained b&w image, which area is in light/shade/highlights.. etc) I’m just interested in how light is brightening up the areas.
3. Is it even possible? hmm.. I would think not? Apart from the amount of light, the local hue of the objects in photo would also affect the final numerical grayscale value, ya?
whats your take?
Unless the ‘B’ value of the HSB model / ‘L’ channel of the LAB model is purely just measuring the amount of lightness/darkness independent of hue? I’m not very sure how it works in detail.. maybe someone can teach me.
Thanks alot
chrisjbirchall,
For the top layer, you stated to set the saturation to Zero. I may be confused here but the Saturation is already at zero…I could move it down to -100. Is that what you meant?
Also,
How do I get the other layer to "Colour" mode?
I could move it down to -100. Is that what you meant?
Yes
How do I get the other layer to "Colour" mode?
Check the layers palette (change the transfer mode from Normal to Colour)
Thank you. I’ll try this.
I tried to open that link but it wouldn’t work
you stated to set the saturation to Zero. I may be confused here but the Saturation is already at zero…I could move it down to -100. Is that what you meant?
It’s not you that’s confused Joey – but it’s not me either!
In an RGB image Zero Saturation is… well… just that: ZERO. No Colour. Zilch!
What is at the middle point of the slider is clearly not zero saturation. So maybe Adobe should have called their slider something like "Deviation from Normal Saturation".
Hey I’m just being pedantic 🙂 We all know what they mean. Cyb pointed you in the right direction on both counts.
By the way. If you like this method, you can easily set up an action to create the layers with their basic settings.
Chris.
In an RGB image Zero Saturation is… well… just that: ZERO. No Colour. Zilch!
And somehow my mind always made the translation between "zero saturation" and setting the saturation to -100 without me being conscious of it. <g>
BTW, Chris, I’ve been playing with that method of getting greyscale from coloour images, and I like it more every day.
