hi i'm robin whalley welcome to lenscraft today i want to look at using something called the quick
mask this is an extremely useful tool that can help you create accurate selections when editing
photos i'll be demonstrating the quick mask using affinity photo but you also find the quick mask
in photoshop the principles of using that are just the same as in affinity i'll be using this
image which i want to prepare for converting to black and white to give me more separation in
the finished image i want to be able to adjust four areas of the image independently these are
the sky the mountains trees and the water so i need to make a good selection of each area and
use the quick mask will help me do that to make my selection i'll be using the selection brush tool
if you're using photoshop rather than affinity photo you have a similar selection brush in the
photoshop tools palette when i click the selection brush the controls for the tool appear in the
context sensitive toolbar over on the left i have the mode buttons where i can choose
to either add to or subtract from a selection i then have three options which help me control
how affinity creates my selection the first of these is snap to edges when i use this option
affinity automatically expands the selection based on the areas i paint over with the brush
this can be a big time saver because it creates an accurate selection and it saves a lot of painting
if i turn this off and paint over the sky you can see that it now doesn't find the edge of the
mountains the other option that affects the quality of the selection is soft edges
clicking this softens the edge of the selection very slightly so that where it's blending with
unselected areas it looks more natural now before i use the quick mask i first want to make
my selection using the selection brush as i paint you can see the selection outlined by the marching
ants at first glance it looks quite good but it's difficult to see clearly because of the marching
ants this is where the quick mask can help you can see the quick mask icon at the top of the screen
in the affinity toolbar when i click to turn it on the marching ants are replaced by a red quick mask
it then becomes more obvious where the selection has some issues that we need to fix
and i'll show you one way to do that in a moment now if i turn the quick mask off by
clicking the icon a second time the display returns to a selection when you come to try
this you might find that your quick mask isn't red like mine if i click the drop down arrow to
the right of the icon you can see a menu where you can select other options i'll switch this
to using a black and white mask and then turn on the quick mask so you can see the difference
by the way if you change to a different mask option with the mask on
the change doesn't show immediately you first need to come out of the mask
and then go back into the quick mask again now you know how the quick mask works
let's use it to refine our selection i'm going to magnify the image and move over the edge of
the mask the red mask shows us the unselected areas whilst the clear area is the selection
this means where we can see the mounting rather than the mask the selection is spilling over the
edge to fix this i can use the selection brush with the subtract mode and then brush over the
problem area notice that as i paint the mask expands automatically up to the edge of the
mountain
once i've cleaned up the problem areas i can turn off the quick mask and return to
the marching ants view of the selection no i could use this selection as it is
if i want to add an adjustment layer to the image whilst the selection's active
it uses that selection to create a mask now i can apply adjustments to just the sky
but instead of doing that i want to save this selection so that i can use it again in the future
the way i'm going to do that is using the channel studio panel where i can save this selection as a
spare channel photoshop has a similar feature that it calls alpha channels at the bottom of
the channels panel i can see the pixel selection when i right click this i can select the option
to create a spare channel now i can right click on the new channel and rename it to sky selection
once i've done this i'll clear the selection by choosing deselect in the select menu if i
want to use the sky selection in the future i only need to right click on the channel
and select the load to pixel option the next area that i want to select in the image is the water
again i'll use the selection brush but you can use other selection tools as well
the quick mask works with all of them
after making the initial selection i'll turn the quick mask on
i can then magnify the area and check for the accuracy of the selection
if there are problem areas i can clean them up using the add and subtract mode
once i've made an accurate selection i can save
it again as a spare channel which this time i'll call water selection
now i could continue and make the tree selection but the process of refining it with the quick mask
is just the same instead i'll save that for another tutorial ultimately the quick
mask mode is quite simple it's just a way of seeing what is and isn't selected in an image
you can then use the selection tools to refine the selection to improve its precision
i hope you found today's video helpful in understanding how to use the quick mask
i'm robin whalley you've been watching lenscraft i'll see you soon for another video