Mono Conversion in Photoshop
There are various ways to convert a colour image to monochrome and Nik Software (free) has excellent mono conversion filters.
1. Greyscale – Under IMAGE – MODE select GREYSCALE and yes to dialogue to discard colour information. Image is now in greyscale mode.
2. Desaturate – Under IMAGE – ADJUSTMENTS select DESATURATE. Image remains in RGB mode.
This can be useful for mixing colour and mono (positive or negative) in the same image.
• Open image.
• In layers palette, copy bg
• Desaturate copy (CTRL and I) if you want negative)
• Add a layer mask and paint to reveal bg colour image
• When satisfied, flatten.
3. Hue and Saturation Layers
This method uses two HS Layers.
• Open image to convert
• In layers palette, create two HS layers
• Highlight top HS layer and open. Move SATURATION slider full left –100 to desaturate the image
• Highlight lower HS layer. Ensure COLORIZE and PREVIEW are checked
• Adjusting the hue and saturation sliders will control how the tones in your colour image are converted. You’ve basically created an infinitely variable colour filter.
4. RGB Channel Selection
Not as versatile as 3, but can give a quick impression of how an image will look.
• Open image to convert
• In the channels palette highlight channel which appears to give the best conversion
• Under IMAGE – MODE select GREYSCALE and yes to delete other channels
5. Lab Colour
Often gives a good result, but needs PS 7 and above.
• Open the channels palette
• Under IMAGE – MODE select LAB COLOUR. The channels palette changes from Red, Green, Blue to Lightness, a, b. Lightness channel contains the detail information, a and b the colour.
• Highlight the Lightness channel and under IMAGE – MODE select GREYSCALE and yes to delete other channels.
6. Channel Mixer
• Either go under IMAGE – ADJUSTMENTS and select Channel Mixer or create an adjustment layer in the layers palette
• Ensure Monochrome box is checked
• PS default is the Red channel, but adjusting the others can create a better conversion where particular effects are wanted, eg infra red, high green, adjust red and blue. Try to keep the overall balance around 100% or information can be lost. CS does the arithmetic for you and also has some presets to try.
One for masochists!!! But, I’m sure good results could be had if you have the patience. Basically, this method takes the image and allows you to blend two selectable channels together, red + green, for example. Setting the blending mode, opacity and applying a mask is also possible. So is selecting two different images.
• Open channels palette
• Under IMAGE select calculations
• Select output to new channel
• Once adjustments are complete, highlight new channel, under IMAGE – MODE select greyscale and yes to discard other channels
8. Black and White
Both CS and later versions of Elements include a dedicated conversion adjustment, which contains, basically, a more advanced version of the Channel Mixer offering more levels of tonal adjustment to various colours. Direct toning is also available, but there are better ways to achieve that.
• Either go under IMAGE – ADJUSTMENTS and select Black and White or create an adjustment layer in the layers palette
• Adjust sliders to taste! I suggest starting with some of the presets.
9. Using a Solid Colour Layer
• Open the image you want to convert.
• Create a duplicate layer
• Desaturate the duplicate layer (shift+Ctrl+U)
• Go into the channels (RGB) bottom right hand corner & then do a Ctrl+left mouse click to highlight the 50% greys.
• Select Inverse (the select tab in the top tabs)
• Then click “new fill layer” and select solid colour. Choose the darkest area of black in the bottom LH corner.
• Then go back to the RGB Layers tab in the right hand corner and change the mode from normal to either Overlay or Softlight. You might want adjust the opacity if you think the blacks are too dark.
• You still need to adjust your levels and colour balance and mid tones in the curves if required.
Thanks to ‘Digital Dave’ for this one!