Help with B&W conversions... thanks!!

[southernbelle]

Hi All!

I was wondering if you could give me some input on what ways you find best to do B&W conversions in Gimp (or other editing systems). I am having some trouble getting the results I want when converting my color portraits to B&W. I have been fine just using the generic grayscale conversions for the most part up until now because I have been trying to perfect other parts of my photography and just haven't been focusing on B&W as much. But B&W is actually my favorite kind of photography. I really like high contrast but find myself loosing too much definition and making the photos too bright when I shoot for that look. Any input would help!! If you could show me a before and after with your explanation that would be awesome!! Thanks so much in advance for the help!

[OsmosisStudios]

I dont use GIMP (I use CS4), but the concept remains the same.

There are 2 main ways of doing it. The simplest is to remove the colour from your image (desaturate) and then play with the levels and curves. Im not sure if GIMP has these controls, but im pretty sure it has something equivalent.

The second is a bit more complex and something im not sure GIMP does (again). In CS4, in the layers palette, there's a CHANNELS tab. If you delete 2 of the 3 channels, you end up with a B/W image and they can be very interesting. Even with that, though, you end up doing some levels and curves.

The trick to a good B/W conversion is getting true blacks, true whites, and a good range between the two. It takes practice.

[dcclark]

I'm a Gimp user, so I'll be a bit more specific. But in general, Osmosis got it right.

I'll focus on the Channel Mixer method, since it gives you more control over the B&W conversion (which is what it sounds like you want).

1. Open the image you want.
2. Go to Colors -> Components -> Channel Mixer
3. In the Channel Mixer box, make sure that both the Monochrome and Preserve Luminosity boxes are checked (they are UNchecked by default).
4. Start moving the red, green, and blue sliders around. This controls how much of each red, green, and blue channel contributes to the final B&W image. Sometimes, an image which has a lot of one color, will look very dramatic if you DON'T allow that color to contribute to the B&W (this is how you can get black skies, when they were very blue in the original).

Play around and have fun!

[southernbelle]

Thanks to both of you! I will definitely play around with the channel mixers and see what I come up with

[spencer28n]

Best Technique for BW Conversion

My favorite so far is Scott Kelby's conversion which is listed in this thread. Basically you add a gradiant map and then use channel mixer. Not sure if you have those options in GIMP.
I also use the Black and White presets in CS4 when I'm feeling lazy, but they don't work as well in my opinion.

Good Luck

[nategesner]

I'm a beginner as well, so let me give you the simpler version.

1. Open image in Gimp.
2. Select "Color" and "Desaturate"
3. You have three options: Lightness, Luminosity, or Average. Selecting one will give you a preview. Choose the one you like the best and select "OK"
4. Select "Color" and "Brightness-Contrast"
5. Adjust the two sliders to adjust brightness and contrast to your liking. The computer will render the image so you can preview the adjustments without actually making the changes.
6. When you get the results you want, select "OK"

In the "Brightness-Contrast" box, you will see a long box labeled "Edit these Settings as Levels." If you select this, it gives you a different way to adjust brightness/contrast levels. I don't understand them, so search Google for a tutorial. However, if you click this button and go into the Levels dialogue, it will then give you a button labeled, "Edit these settings as Curves." Curves are easy to learn and I highly recommend taking a few minutes to watch a video lesson and then toy around with them.

Hope this helps!

[kencaleno]

- Black & White conversion from colour #1

Ctrl+J
Image> Calculations
Background layer
Red
Background Layer
Red
Multiply
New channel
Image> Mode> Greyscale
flatten/save

Regards, Ken

[kentuckyranger]

The best way to do B&W is from RAW files.
I've found that converting jpeg color files to B&W can work OK, but leave allot to be desired in the control department.
Raw format gives you total control over the image, even in B&W.
You can use the cameras internal controls to take B&W images but then you have a B&W image in jpeg, nothing more.
If you take the image in RAW format you have so much control over all aspects, even the real world addition of B&W filters, giving you a huge array of options.
Back in my early days I found myself in the field with my camera and a roll of Pan-X film thinking wow, if I only had a green, red or blue filter to enhance what I was taking a photo of.
Well, with RAW, not only do I have that option, I can also apply the filter and see just what effect it has on my image without altering the original.
Also, if I decide it looks better in color, it's a done deal.
RAW format is the most powerful function a dSLR has in its arsenal because it captures the image in its truest form, better than film ever thought of being.

[Joey the girl]

Originally Posted by kencaleno

- Black & White conversion from colour #1

Ctrl+J
Image> Calculations
Background layer
Red
Background Layer
Red
Multiply
New channel
Image> Mode> Greyscale
flatten/save

Regards, Ken

I know that not everyone (especially beginners) can appreciate the simplicity or seeing photoshop instructions written this way, but I personally love it! It's so direct and step by step. Thanks, Ken, for keeping it simple!

[southernbelle]

Thanks y'all!