I wrote a book and published it in 2001
called ‘Vermeer’s Camera’.
The book was about the idea that
the great Dutch painter
used the camera obscura,
which is a predecessor of the
photographic camera
and it’s just a lens and project an image. 
It’s quite an old idea and lots of people
have suggested it
but I had some new arguments.
You can take paintings 
of architectural scenes and interiors like 
Vermeer’s and you can work the perspective backwards.
You can go from the two-dimensional
image to the three-dimensional scene
and you can reconstruct the architecture,
and Vermeer it’s clear painted quite a
number of pictures, maybe as many as 8 or 10
in one room, his studio,
and in each case
you can determine his viewpoint
and you can see the extent of what
is visible in the picture, which is a
pyramid lying on its side, whose point is
at the viewpoint.
If you the lines of this pyramid
back 
through the viewpoint to meet the back
wall,
you describe a rectangle in each case,
and in at least six
cases that rectangle is the exact
size of Vermeer’s painting. It’s
very difficult to see how that could
arise
other than him having a lens projecting
images
and they’re the same size as the pictures
because he has traced them, 
and that’s the essence of my argument.
 
0:01:40.050,0:01:44.220
[Film] Sometimes when I’m trying to get to 
sleep all I can think about is trying to paint a Vermeer,
who some consider the greatest painter of
all-time. At the face of it that seems
almost impossible
because I'm not a painter.
[Prof Steadman] A man called Tim Jenison,
who’s an engineer, his daughter gave him a
copy of my book
for Christmas, and he got very interested
and he thought that he could take the
argument
a bit further. I left two questions 
unresolved in the end of the book,
I had some ideas but
one of them was that if you project
an image
onto a wall or a screen as you would
with a simple camera obscura,
then it’s mirrored – how could you then,
it’s clear that the paintings themselves
are not mirror images, so how could you
reverse that?
That’s not too complicated. The
other problem was much more difficult:
if your– the cameras that they were using
in the 17th century, some of them were
little boxes like modern photographic
cameras,
but mostly they were booths,
they were tents
or cubicles you were inside and
you're in the darkness,
and how could you paint? You could
draw, you could trace an image, 
but how could you see the colours
of your paints and get
the hues right. One reason that people think
that Vermeer used a camera obscura
or some kind of optical aid is that his
paintings do look
photographic, and I think what we mean
when we say photographic
is that the tones are absolutely true,
that’s what we
see that resembles photographs, so how
could you do that
inside a camera. And Jenison had this idea 
that you could, he had an idea 
for a device
which would allow you to paint
in semi-darkness and
get the tones right, and so he decided to
paint a Vermeer, although he's never
painted in his life.
[Jenison montage] So I’m going to construct
a replica the exact room where
The harpsichord, the Spanish chair,
the viola,
the rug.
The winds trying to blow my shape.
Well this certainly is not easy.
Well this is Tim Jenison’s device, it’s
part of his
set up. It’s just her a little flat
mirror on
a stick, as you see,
and the way it works is that you project
a camera image
onto a wall, and you put your canvas
flat in front of that image on the wall,
and you put this, you have this mirror,
you look down on it,
and in the mirror you see part of the
optical image, and as you look past
the edge of the mirror you can see part of your canvas,
and then you apply paint
just by the edge of the mirror, and
if the hue and tone of the paint
match what you see in the mirror, then
you've got a match with the optical image.
In fact, at that point you can’t see
the edge of the mirror,
and that's the essence of how it’s done,
of how the image is transcribed.
The fact that it’s a mirror means that
it reverses
the optical image so you're back with
the correct way round
picture and
this also solves the problem of working
in low light because
everything's in low light, the
images in low light, your canvas is in
low light but if you’re matching
then it doesn't matter.
This device that Jenison uses,
it's simple, it's certainly within
the scope of 17th century technology,
and it works. There’s no doubt that
you can produce, as an amateur, you can
produce Vermeer-like photographic effects
by transcribing the optical image,
but the question that remains is
did Vermeer use this?
We know very little about Vermeer,
we know very little about his life,
nobody writes about his methods, he
didn't write about his methods, he had
so far
as we know, no pupils,
so the only places you can look are
in the paintings themselves and then
could you find mentions in
contemporary literature, and Jenison
and I have looked very hard in books on
painting techniques such as they are
of the period, and there’s nothing.
This device is a bit like
a sort of short distance telescope, it’s a bit like
a reflecting telescope, a telescope
with a mirror in it, but reflecting telescopes
weren’t built until the 18th century. 
