BW Conversion, please share

[lastboltnut]

Hi,

I have an illustration between Channel Mixing and Desaturation methods for BW conversion from colour pic. #1 is the orignal colour pic. #2 is converted by Desaturation method in PS and #3 is converted by Channel Mixing method. #4 is the same item shot with BW mode from S3 IS.

From the look of #2 and #4, it is obvious that they are very similar and should be converted by the same technique.

Now lets compare the 2 methods. Look at the right most 2 pegs (the half buried red and blue in #1), in #2, they have very close tone (due to the same luminance value) although from #1 they are diff in colour. But in #3, they are of diff contrasting tone. This is posible due to channel mixing in the RBG colour.

Hope this sharing can contribute to those interested.

#1 Original Colour


#2 Conversion by Desaturation


#3 Conversion by Channel Mixing


#4 BW Mode from S3 IS


Just hope to share will all what I have just learnt and please feel free to comment.

If you have other method, please share if you dun mind. So that I can learn another method.

Thanks!!

[GeckoZ]

Originally Posted by lastboltnut Hi, I have an illustration between Channel Mixing and Desaturation methods for BW conversion from colour pic. #1 is the orignal colour pic. #2 is converted by Desaturation method in PS and #3 is converted by Channel Mixing method. #4 is the same item shot with BW mode from S3 IS. From the look of #2 and #4, it is obvious that they are very similar and should be converted by the same technique. Now lets compare the 2 methods. Look at the right most 2 pegs (the half buried red and blue in #1), in #2, they have very close tone (due to the same luminance value) although from #1 they are diff in colour. But in #3, they are of diff contrasting tone. This is posible due to channel mixing in the RBG colour. Hope this sharing can contribute to those interested. #2 Conversion by Desaturation #4 BW Mode from S3 IS Just hope to share will all what I have just learnt and please feel free to comment. If you have other method, please share if you dun mind. So that I can learn another method. Thanks!!

oh thanks for the tips! I nv noticed that BW mode in camera was actually purely desaturation.

[theRBK]

Can try using 2 Hue/Saturation layers...top layer just desat, bottom layer adjust the lightness of the various colours...can bring out more contrast in the image, especially for such colourful images...

[lastboltnut]

Thanks theRBK for sharing. And do you overlay them after that?

Originally Posted by theRBK Can try using 2 Hue/Saturation layers...top layer just desat, bottom layer adjust the lightness of the various colours...can bring out more contrast in the image, especially for such colourful images...

[agape01]

Search the threads, there are many who have asked this question already.

[GeckoZ]

Originally Posted by theRBK Can try using 2 Hue/Saturation layers...top layer just desat, bottom layer adjust the lightness of the various colours...can bring out more contrast in the image, especially for such colourful images...

Very nice, I'd nv tried this before. now, this looks like more like the BW i usually see.

[theRBK]

Originally Posted by lastboltnut Thanks theRBK for sharing. And do you overlay them after that?

oh, I meant in adjustment layers, normal mode......donno if anyone has tried this method before...thought it up sometime before...my boss challenged me to produce interesting b/w images for this job...i have read of others using an overlay for the second hue/sat layer...but I find the method I suggested gives more control as can adjust individual colours...experiment away

[theRBK]

Originally Posted by agape01 Search the threads, there are many who have asked this question already.

there really should be a sticky for this...

[Akira Fudou]

hi sorry long bang this thread... how to create some colors in the BW pic... eg. give some clours to the peck

[GeckoZ]

Originally Posted by Akira Fudou hi sorry long bang this thread... how to create some colors in the BW pic... eg. give some clours to the peck

Hi Akira, you will have to do layer masking in photoshop for such mission. But selective colouring in photos is supposed to be more of a graphic designer's job instead of a photographer.

[timothychanzl]

Thanks ! I think I'll desat using the channel mixers in future.
Closer to my desired end result.

Used to desat and then adjust using curves. Guess I must be creating alot of digital artifacts especially since I'm working with JPEG.

[lastboltnut]

No mention timothychanzl. Please share here if you discover any other good/better method.

Originally Posted by timothychanzl Thanks ! I think I'll desat using the channel mixers in future. Closer to my desired end result. Used to desat and then adjust using curves. Guess I must be creating alot of digital artifacts especially since I'm working with JPEG.

[t33jay]

How about Calculation?

[GeckoZ]

Originally Posted by t33jay How about Calculation?

what calculations do you mean? please elaborate.

[Zaknafein]

i just tried to convert using the 1st pic...
used 2 hue/sat layers.
bottom layer = overlay, adjust hue or lightness to my satisfaction
top layer = de-saturate



what do u guys think?

[creampuff]

There are several methods for B&W conversions. Looking at the bucket image, just using the red channel alone will give a nice enough image (notice the difference between the red and blue pegs), certainly better than a greyscale conversion alone.


Aside from desaturation or Channel Mixer (good for controlling highlights) that was used by TS, can also try the following:

Can also use the Lab Lightness Channel method. (Convert image to Lab Color, Use Lightness channel, discard other channels. If image too light, can duplicate layer in multiply mode, add layer mask, paint with white. Vice versa if image is too dark, convert to greyscale and save).

Can also try Calculations method. (Image>Calculations) In effect you are mixing the channels from the image, so source files should be the same. Set blend to multiply or overlay or soft light, and then pick your channels, eg. green and blue, etc. as you preview the different combinations. Finally change image to greyscale mode and save.

[allsmilez]

This is my try based on gradient map approach. Gives B+W that can be adjusted to higher contrast, may not be suitable for all pics. Didn't max out the contrast for this pic but u can have quite alot of fun with this method.



Basically you can just add a gradient map adj layer, and then a channel mixer above it. The reds can set about 75% then play around with the blues and greens till you get a high contrast image.
cheers.

[lastboltnut]

Wow! This thread finally has got interest in discussion! Thanks guys for contributing....I will try these method when I have a chance......hope this thread can help to summarise the BW conversion methods for all who are interested!

Do contribute if you have other methods.

Thanx again!!

[creampuff]

As can be seen from the many versions, there are subtle differences in tonal range and how objects/scenes which vary in hue can appear when converted to B&W. Personally, unless a deliberate high contrast effect is needed, my preference has always been for a B&W image with a nice range of tone with good shadow detail but not blown out highlights.

[shadie]

Originally Posted by Zaknafein i just tried to convert using the 1st pic... used 2 hue/sat layers. bottom layer = overlay, adjust hue or lightness to my satisfaction top layer = de-saturate what do u guys think?

Love the tones.