Difference between Blend Ranges

[footeg]

Could someone please tell me the difference between Source Layer Ranges & Underlying Composition Ranges in Affinity Photo & when to use each of them. Thanks.

[Alfred]

This page (thanks, @drippy cat!) shows what can be achieved by tweaking the Underlying Composition Ranges graph:

https://theeagerlearner.com/luminosity-masks-try-blend-ranges-instead/

 

You can similarly tweak the Source Layer Ranges graph to change the opacity of the source image. For example, if you have a greyscale image on a black background and you drag the left-hand end of that graph all the way down, the black pixels in the image will become completely transparent. All of the other pixels which are not pure white will become semitransparent, but you can correct that by dragging the right-hand end straight across towards the left until full opacity of the non-black pixels is restored.

[footeg]

Thanks Alfred, I think I've got a better handle on it now. Does this mean that Source Layer Ranges are used on the base layer while the composition ranges affect the selected adjustment layers etc. Also if you use the former to get a transparent background can you then save this as a mask? Thanks again.

[Alfred]

48 minutes ago, footeg said:

Does this mean that Source Layer Ranges are used on the base layer while the composition ranges affect the selected adjustment layers etc.

 

That sounds about right, based on my limited understanding!

 

49 minutes ago, footeg said:

Also if you use the former to get a transparent background can you then save this as a mask?

 

You can go to the Layers panel and Cmd-click on a Mac (or Ctrl-click on Windows) on a layer thumbnail to create a 'marching ants' selection of all the non-transparent pixels in the chosen layer. Does that help?

 

[footeg]

Thanks again Alfred. That certainly helps. I am doing my best to get to grips with this excellent program and have just received the workbook. Geoff