Masking photos in Affinity Photo doesn't work

[AMC68]

I want to make a backgound montage of several photos. In Photoshop I put each photo on a separate layer, position them on the background and then use masks on the photos to blend the backgrounds, taking out the hard edges.

I've tried this in Affinity and can't get it to work. If I layer one photo on to another, add a mask layer and try paint out the edges absolutely nothing happens! I've tried with red rectangles and green restangle and they mask just fine but it doesn't seem to work with photos as it does in Photoshop.

Can someone point out what I have missed.

Thank you

[toltec]

Amended

 

[AMC68]

Thanks. I tried that and masking still doesn't work. I can use the Erase brush to remove the portion I want but I can't amend the mask. Neither black nor white has any effect when I paint the mask. I am obviously doing something very silly but i cannot work out why! Its driving me mad.

[toltec]

I have the mask layer selected and using the paintbrush with black paint, am "erasing" (or masking) the image.

 

I created the mask by selecting the image (pixel layer) and clicking on the mask icon.

 

[lepr]

.

[AMC68]

Thanks, toltec. That’s what I am trying to do - it just isn’t working.

 

Thanks, owenr - No, I didn’t even know Protect Alpha existed! It sounds promising. I have just stopped for the night having banged my head against a brick wall for too long. I will check this out tomorrow.

 

Many thanks to you both for your time. Fingers crossed!

 

 

[v_kyr]

1 hour ago, toltec said:

If the photos are Image layers (because you "Placed" them), you can't. They are treated as independent images and you can't perform pixel level edits.
...
If you need to do this a lot, I suggest you create a keyboard shortcut for "Rasterize".

No rasterization is not needed for placed images at all here, just for masking them via layer masks ...

... I assume the OP has probably some other setting missmatch here instead.

[toltec]

8 minutes ago, v_kyr said:

No rasterization is not needed for placed images at all here, just for masking them via layer masks ...

 

 

 

Yes, quite right, I got my wires crossed 

 

I have deleted the post to avoid confusion. Thank you

[AMC68]

Thanks everyone.

owenr hit on the solution.

When I opened the file again this morning and looked at 'Protect alpha' it wasn't ticked so I assumed my hopes were going to be dashed. However I ticked it and then unticked it. To my surprise the masking tools then worked as I had originally expected!

Having denied all knowledge of 'Protect alpha' I now have a vague recollection of making use of it in a tutorial I was doing a little while ago. I suppose the problem was a legacy of that even though it didn't appear to be ticked today.

Problem solved. I knew it had to be something I had done.

Thanks again