For no particular reason (other than creating the next Hollywood blockbuster
single-handed), I was wondering how to go about doing a bluescreen thingy,
such that I can superimpose something onto a water scene.

I have a blue screen (roller blind, which seems to work), and a toy (ahem,
*model*) Stingray. I also have some footage of a local loch. I'd like to, if
possible, make it look as if Stingray is cruising along on the loch. I'm not
looking for big splashes or the amazing dolphin-like leaps that the real
Stingray does - just an incongruous cruise past a local landmark.

I'm thinking of suspending the model from some extremely fine monofilament
line (actually 'invisible' sewing thread) and moving it along in front of
the camera. The main problem would seem to be the waterline - how to make
the lower part of the hull disappear convincingly. Would dipping the model
into a tray of water work? I'm thinking that the most of the water, apart
from some ripples, would reflect the blue screen and thus be removed when
the composite is done.

What about taking the newbie troll-bait approach and trying to do it in
software? IOW, film the bluescreen part without the tray of water, and then
remove the lower part of the hull in each frame. Tedious but doable, I
guess, but I don't see how to give the impression of ripples or a wake.


--
Wally
www.artbywally.com/FiatPandaRally/index.htm
www.wally.myby.co.uk

"Wally" wrote in message
...
For no particular reason (other than creating the next Hollywood
blockbuster
single-handed), I was wondering how to go about doing a bluescreen
thingy,
such that I can superimpose something onto a water scene.

snip

What about taking the newbie troll-bait approach and trying to do it
in
software? IOW, film the bluescreen part without the tray of water,
and then
remove the lower part of the hull in each frame. Tedious but doable,
I
guess, but I don't see how to give the impression of ripples or a
wake.


A combination of blue / green screen, After Effects and masks I
suspect. Time for deep pockets and lots of time....

:::Jerry:::: wrote:

A combination of blue / green screen, After Effects and masks I
suspect. Time for deep pockets and lots of time....

Haven't used After Effects - I'm close to buying ULead Mediastudio Pro 7
after trying out the demo version (can get it at a good price, thanks to the
upgrade path). I think it does masks and things, but I haven't looked at any
of that yet. The full version also comes with something called Video Paint,
which I gather is some sort of retouching package. It does sound awfully
tedious, though.

How does the combination of blue and green screen work? Why two colours,
IOW?


--
Wally
www.artbywally.com/FiatPandaRally/index.htm
www.wally.myby.co.uk

"Wally" wrote in message
...
snip

How does the combination of blue and green screen work? Why two
colours,
IOW?


I was just trying to point out that you don't have to use blue, green
is another colour that is widely used, the main point being is that
the colour of the screen shouldn't clash with the colours that are
going to be placed against it - otherwise there is the possibility of
a presenters shirt (for example) also becoming invisible !...

":::Jerry::::" wrote in message

How does the combination of blue and green screen work? Why two
colours, IOW?

I was just trying to point out that you don't have to use blue, green
is another colour that is widely used, the main point being is that
the colour of the screen shouldn't clash with the colours that are
going to be placed against it - otherwise there is the possibility of
a presenters shirt (for example) also becoming invisible !...

Oh right. Yes, I'm aware of the problem of bits disappearing - I might have
to use a different colour - had a look at Stingray, and it has
bluey/tourqoisey bits. Perhaps a custom panel done in Cadmium Yellow (which
looks orange, and is very opaque) would be a better idea...

A combination of blue / green screen, After Effects and masks I
suspect. Time for deep pockets and lots of time....

Haven't used After Effects - I'm close to buying ULead Mediastudio Pro 7
after trying out the demo version (can get it at a good price, thanks to
the
upgrade path). I think it does masks and things, but I haven't looked at
any
of that yet. The full version also comes with something called Video
Paint,
which I gather is some sort of retouching package. It does sound awfully
tedious, though.

MSP's abilities with blue/greenscreen are a source of annoyance for a lot of
regular users. The lower-end Ulead products are beginning to acquire the
feature, while the upper end have been neglected for some time (apparently
so - I don't have much need for compositing).

If you can get hold of an earlier version (there was a fully legit version
of it on the cover of a January magazine - sorry can't remember which one)
then you can make use of some of the free compositing filters offered at
jushhome.com, which improve on the abilities of Ulead's own overlay filters,
but (unfortunately) they have yet to be compiled for version 7.

"Wally" wrote in message
...
":::Jerry::::" wrote in message

How does the combination of blue and green screen work? Why two
colours, IOW?

I was just trying to point out that you don't have to use blue, green
is another colour that is widely used, the main point being is that
the colour of the screen shouldn't clash with the colours that are
going to be placed against it - otherwise there is the possibility of
a presenters shirt (for example) also becoming invisible !...

Oh right. Yes, I'm aware of the problem of bits disappearing - I might
have
to use a different colour - had a look at Stingray, and it has
bluey/tourqoisey bits. Perhaps a custom panel done in Cadmium Yellow
(which
looks orange, and is very opaque) would be a better idea...

It would be a bad idea, TBH.

Blue was used because (on film) it was furthest on the spectrum from any of
the colours in skin tones. Green has been brought in too, so that actors can
wear jeans without them disappearing.

G Hardy wrote:

Oh right. Yes, I'm aware of the problem of bits disappearing - I
might have to use a different colour - had a look at Stingray, and
it has bluey/tourqoisey bits. Perhaps a custom panel done in Cadmium
Yellow (which looks orange, and is very opaque) would be a better
idea...

It would be a bad idea, TBH.

Blue was used because (on film) it was furthest on the spectrum from
any of the colours in skin tones. Green has been brought in too, so
that actors can wear jeans without them disappearing.

But..., Stingray doesn't have fleshtones. It's a whitish submarine with
bluey bits. There is a Troy Tempest figure, but he's very small, and rather
hard to see through the little windows. If the most effective isolation is
to be had by using a background which is the complement of the thing we want
to isolate, then an orangey colour against blue is about as good as it gets.


--
Wally
www.artbywally.com/FiatPandaRally/index.htm
www.wally.myby.co.uk

Oh right. Yes, I'm aware of the problem of bits disappearing - I
might have to use a different colour - had a look at Stingray, and
it has bluey/tourqoisey bits. Perhaps a custom panel done in Cadmium
Yellow (which looks orange, and is very opaque) would be a better
idea...

It would be a bad idea, TBH.

Blue was used because (on film) it was furthest on the spectrum from
any of the colours in skin tones. Green has been brought in too, so
that actors can wear jeans without them disappearing.

But..., Stingray doesn't have fleshtones. It's a whitish submarine with
bluey bits. There is a Troy Tempest figure, but he's very small, and
rather
hard to see through the little windows. If the most effective isolation is
to be had by using a background which is the complement of the thing we
want
to isolate, then an orangey colour against blue is about as good as it
gets.

True enough. I was really going for the question a couple of posts ago where
you were asking "Why blue/green?"

If you can make a good enough backdrop (i.e. where the entire background has
the same pixel colour value), any colour will do, as long as there are no
foreground objects which will map to the same colour. In reality, this is
quite difficult, though. For my next project, I'm planning to "hand paint"
(rotoscope) my mattes or buy something to use outside MSP, such as
Chrominator.

"G Hardy" wrote in message news:atO2e.204

True enough. I was really going for the question a couple of posts ago
where
you were asking "Why blue/green?"

It wasn't the specific colours as such - I thought Jerry was alluding to a
technique which uses both in some way.


If you can make a good enough backdrop (i.e. where the entire background
has
the same pixel colour value), any colour will do, as long as there are no
foreground objects which will map to the same colour. In reality, this is
quite difficult, though.

Making an even-toned background isn't too hard (the cadmium-based paint I
mentioned is extremely opaque - no streakiness, and brushes out as even as
you like). The difficult bit would seem to be getting it evenly lit.


For my next project, I'm planning to "hand paint"
(rotoscope) my mattes or buy something to use outside MSP, such as
Chrominator.

What is this rotoscoping I keep seeing mentioned?