How do I edit only part of a .jpg document

[ColchesterDave]

Hi,

This is my first post and I'm a novice with Affinity Photo. I've watched all the tutorials to do with editing selections and layers, but can't seem to make the app do what I want it to.  It's fairly simple and must be possible, I'm just not getting it!

I have a .jpg that has been produced from a stacking program, Sequator. It contains 2 main elements, the foreground and the night sky, including the Milky Way. I want to blow the highlights and whites UP in the sky (without affecting the foreground) and reduce the highlights and whites DOWN in the foreground (without affecting the sky) - sounds simple, but I have spent hours trying to make it work and got nowhere!  Please help!!

[John Rostron]

You have a very low contrast between the foreground and background which makes making a selection difficult. I fist duplicated the background layer. I then  used the Lasoo Tool to draw around the sky. I then applies a Curves adjustment  to increase the contrast making the stars brighter and the shadows darker. I then returned to the original background and inverted the selection and applied a curves adjustment to reduce the contrast. This was the result:

Not much of an effect I know, but given the subject matter...

John

[markw]

Here’s my take on your pic. It all comes down to masking basically.
All Live Filters and Live Adjustment layers in AP can be painted on directly with the Paint Brush tool in grey scale so as to control which areas of the image that layer affects.

Lighthouse.afphoto.zip

[Fixx]

Select sky, adjust it lighter.

Invert selection, adjust light parts darker.

I would use curves tool to target right tones.

Of course, you can get better result if you can make stacking app to handle tone mapping, or export two versions and use AP for tone mapping/stack development.

[ColchesterDave]

Hi Fixx,

Thanks for the quick reply! How do I select just the sky? Sorry, I really am a beginner with AP.

I know where the invert selection and curves tools are, but selecting just the sky is something I just can't work out.

Thanks, Dave

[IanSG]

4 hours ago, ColchesterDave said:

Hi Fixx,

Thanks for the quick reply! How do I select just the sky? Sorry, I really am a beginner with AP.

I know where the invert selection and curves tools are, but selecting just the sky is something I just can't work out.

Thanks, Dave

You can make the difference between the sky and the foreground more obvious by using a curves adjustment or playing with the exposure.  Once you've made your selection you can save it either as a file or a spare channel - this isn't necessary, but it does provide some peace of mind!