Reduce opacity

[SPD54]

I want to take the opacity of half of a picture down would I use a mask as not used a mask and not sure if I'm thinking correctly. 

Apologies if this is in the wrong forum. 

Steve

[v_kyr]

There are many different ways to do that beside masking, so for which Affinity app?

[SPD54]

Affinity photo 2.2

[v_kyr]

I show you quickly with a mask in APh v1, for APh v2.2 it's pretty much the same procedure ...

1. Create a Mask down your image
2. Select the mask layer in the layers panel
3. Select the rectangular marquee selection tool and select with that half of your image
4. Select the Fill can tool and apply a middle gray fill, the choosen gray level color (dark to ligh gray etc.) will influence the luminance/shine through degree here
5. Dismiss/hide the selection Ctrl-D/Cmd-D

A quick made Screencast ...

 

 

[carl123]

Select half the image with the rectangular marquee tool

Cut and paste to a new layer

Lower the opacity of the new layer (in the Layers panel)

[SPD54]

Thanks now sorted through your help.

[Pšenda]

If you are not comfortable with a sharp transition in transparency, you can use a mask with a gradient.