Transforming a smooth or progressive selection into a sharp one

[jean baptistep86491065]

How do I change a progressive or smoothed selection into a sharp one?

[Stephen Marsh]

One way:

1) Enter QuickMask mode by pressing q

2) Run a threshold adjustment on the temporary QuickMask channel 

3) Press q to exit QuickMask mode and return to a selection

[Trevor.Dennis]

I like to use levels or curves directly so you can control where the hard boundary is going to be, and keep some anti alias to avoid any jaggies.

[jean baptistep86491065]

Your method seems very good but could you explain it step by step because I don't realy understand how you arrive to this result 🙂
I join an exemple of file with a registred smooth selection I need to sharpen 🙂

[jean baptistep86491065]

In fact I succeed with your method.
What I didn't have was the mask level window.
You had to press the cmd and L keys while selecting the mask and after to follow what you wrote.
The result is perfect !
Thanks a lot

[Conrad_C]

Another way is to choose Select > Select and Mask, and in the Global Refinements options group, increase the Contrast option, which increases the contrast of a feathered mask edge, making it sharper. Similar to doing it manually with Levels.

[Trevor.Dennis]

Quick Mask is one of those underrated tools in Photoshop, which is a pitty because it can be so incredibly useful.  I also suspect that a lot of people miss out on both Quick Mask and Layer Masks by not realising that a lot of what can be done to an image layer, can also be done to a mask.

You could spend forever demonstrating this, so for a very quick example, Render > Clouds with a Reveal All layer mask selected produces a nice texture.  Of course you could get an identical effect using Render > Clouds to a layer with Red and Black selected as your foreground and background colours, but this effectively shows the flexability of adding effects to masks rather than layer contents.

[jean baptistep86491065]

With your help, here's the solution
1- Make selection
2- Press q
3- Press ctrl + L
4- Adjust the arrows
5- Select the mask in the layer "channel" and reveal its selection
6- Press q
That's all 🙂