AV News 194 - November 2013
Remember that any of these adjustments that you have made can be revisited
at any stage and changed to suit. I often find that I do something that I think will
work, run the sequence and realise that the background is too dark, the position
of the object is wrong or that bright red border that I chose really doesn't work.
No problem, just go back and change it.
Now for something a bit more tricky. The technique above almost inevitably
produces hard edges to the second image. Could we have soft edges to our
second image so that the images blend together better?
Yes, but we need to get into 'Masks'.
Using a mask to add the second image to a slide
A little aside about masks. The Venetian lady
in this photo is wearing a mask. The mask is
a solid, white plastic, object with bits cut out
so that we can see parts behind. The mask
also has decoration, an image, applied to the
surface.
In PTE terminology that physical mask in
its entirety is represented by a 'Mask
Container', in which there are two images.
One image represents the shape of the
mask, i.e. the parts that are cut out. As with
the Venetian mask of white plastic, our PTE
mask is white where we don't want to see underneath and black where we do
want to see underneath. But what is most useful in PTE is that different shades
of grey give different amounts of opacity.
There is a second image in the 'Mask container' that represents the image
which is pasted on the front of the mask. To create a soft edge to our second
image, we need a mask which is opaque in the centre (i.e. the image of it will
be white), but is see through round the edges (black), but there is a gentle
gradation from white to black at the edges.
To create the mask:
· In O&A, with your base image not
selected, click on the 'Add Mask' icon.
This will bring up a dialogue box which,
inevitably, gives you lots of options. The
image gives you an impression of the
mask which will be created.
· Let's keep it simple to start with. Make
sure the 'From template' button is lit and
the 'Style' is 'Rectangle'.
Forget the other options at the moment,
you can come back to them later. Your
mask will be a white square blending to
black at the edges.
· Click 'OK'
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