Photoshop Color Effect Question

This seems very simple..but I can't seem to do it.

How do I change a photo into one shade of color & white? Like so



or so:

 

What's the actual photo you are trying to change? A mask might work for what you are trying to achieve.

 

I don't know if the 2 are the same effect - I'm more interested in the obama pic right now, but I'd also like to know how to make the 2nd effect, say with this pic:



A vector mask? What do I do after I create the mask?

edit: ok I got the 2nd effect - grayscale, then 'tint' with the color of your choice. Still would like to know how to do the obama blue/white effect

 

For this effect on photoshop..

from the menu

1. image/adjustments/hue saturate: use the saturation slider to remove the colours.

then

2. image/adjustments/color balance: use the sliders to add some colour back.

job done.

 

The first image just looks like image/adjustments/posterize with some colour added perhaps later.

Raising the contrast before you posterize will give differnet results.

 

There's many different ways how colours/shades can be manipulated - using layer blend modes in combination with levels/curves control and hue/saturation. I would suggest that you play around with all of these settings until you get the desired effect. to get that effect I would simply 'colourise' the photo with hue/saturation and play with the levels layer until you get the desired shadows/midtones effect that you like. goodluck!

 

halo, this result I try with the Psd and Ai
you can view the tutorial here http://www.gomediazine.com/tutorials/gigposter-design-the-new-sex/