Photoshop Effects

[Summayah5FC7]

I'm assuming this was a photo.

What tools were used to achieve this effect?

[Stephen_A_Marsh]

Each separate person was isolated and composited into the final.

Perhaps threshold based off the colour composite or a single channel to create the basic black and white contrast image... But that would be too harsh, so perhaps something like Filter Gallery > Sketch > Photocopy

I'm not sure on the selective colouring, perhaps a gradient map.

[Summayah5FC7]

thanks. i'll have a go.

[c.pfaffenbichler]

A posterized, clipped image with a Gradient Overlay Layer Style (edit: set to the Blend Mode »Screen«) might be an option. 

[Summayah5FC7]

Thanks. What was the reason for doing the curves adjustment

[c.pfaffenbichler]

Curves (or Levels etc.) Layers beneath the Posterize Layer can be used to »salvage« detail that might get lost otherwise. 

In some cases it might even be advisable to apply some sharpening (as Smart Filter) locally to that same end. 

[Summayah5FC7]

Thanks.

[c.pfaffenbichler]

You’re welcome. 

I should have posted screenshots to illustrate: 

[c.pfaffenbichler · Accepted solution]

The additional superimposed detail can be achieved with a Layer with the Blend Mode »Screen« Clipping Masked to a Group.