_Stereoscopic Queries._--Can any of your readers inform me what are the
proper angles under which stereoscopic pictures should be taken?
Mr. Beard, I am informed, takes his stereoscopic portraits at about 6½°, or
1 in 9; that is to say, his cameras are placed 1 inch apart for every 9
inches the sitter is removed from them. The distance of the sitter with him
is generally, I believe, 8 feet, which would give 10-2/3 inches for the
extent of the separation between his cameras. More than this has the
effect, he says, of making the pictures appear to stand out unnaturally;
that is to say, if the cameras were to be placed 12 inches apart (which
would be equal to 1 in 8), the pictures would seem to be in greater relief
than the objects.
I find that the pictures on a French stereoscopic slide I have by me have
been taken at an angle of 10°, or 1 in 6. This was evidently photographed
at a considerable distance, the triumphal arch in the Place de Carousel (of
which it is a representation) being reduced to about 1¼ inch in height. How
comes it then that the angle is here increased to 10° from 6½°, or to 1 in
6 from 1 in 9.
Moreover, the only work I have been able to obtain on the mode of taking
stereoscopic pictures, lays it down that all portraits, or near objects,
should be taken under an angle of 15°, or, as it says, 1 in 5; that is, if
the camera is 20 feet from the sitter, the distance between its first and
second position (supposing only one to be used) should not exceed 4 feet:
otherwise, adds the author, "the stereosity will appear unnaturally great."
When two cameras are employed, the instructions proceed to state that the
distance between them would be about 1/10th of the distance from the part
of the object focussed. The example given is a group of portraits, and the
angle, 1 in 10, is afterwards spoken of as being equivalent to an arc of
10°.
Farther on, we are told that "the angle should be lessened as the distance
between the nearest and farthest objects increase. Example: if the farthest
object be twice as far from the camera as the near object, the angle should
be 5° to a central point between these two.
Now, I find by calculation that the measurements and the angle here
mentioned by no means {506} agree. For instance, an angle of 15° is spoken
of as being equivalent to the measurement 1 in 5. An angle of 10° is said,
or implied, to be the same as 1 in 10. This is far from being the fact.
According to my calculations, the following are the real equivalents:--
An angle of 15° is equal to 1 in 4.
" 12° " 1 in 5.
" 10° " 1 in 6.
" 6½° " 1 in 9.
" 6° " 1 in 10.
" 5° " 1 in 12.
" 4° " 1 in 15.
Will any of your readers oblige me by solving the above anomalies, and by
giving the proper angles or measurement under which objects should be taken
when near, moderately distant, or far removed from the camera; stating, at
the same time, at how many feet from the camera an object is to be
considered as near, or distant, or between the two? It would be a great
assistance to beginners in the stereoscopic art, if some experienced
gentleman would state the best distances and angles for taking busts,
portraits, groups, buildings, and landscapes.
It is said that stereoscopic pictures at great distances, such as views,
should be taken "with a small aperture." But as the exact dimensions are
not mentioned, it would be equally serviceable if, to the other details,
were added some account of the dimensions of the apertures required for the
several angles.
In the directions given in the work from which I have quoted, it is said
that when pictures are taken with one camera placed in different positions,
the angle should be 15°; but when taken with two cameras, the angle should
be 10°. Is this right? And, if so, why the difference?
In the account given by you of Mr. Wilkinson's ingenious mode of levelling
the cameras for stereoscopic pictures, it is said the plumb-line should be
three feet long, and that the diagonal lines drawn on the ground glass
should be made to cut the principal object focussed on the glass; and "when
you have moved it, the camera, 8 _or_ 10 feet, make it cut the same object
again." At what distance is the object presumed to be?
Any information upon the above matters will be a great service, and
consequently no slight favour conferred upon your constant reader since the
photographic correspondence has been commenced.
[phi].
_Photographic Portraits of Criminals, &c._--Such experience as I have had
both in drawing portraits and taking photographs, impels me to hint to the
authorities of Scotland Yard that they will by no means find taking the
portraits of gentlemen that are "wanted" infallible, and I anticipate some
unpleasant mistakes will ere long arise. I have observed that inability to
recognize a portrait is as frequent in the case of photographs as on
canvass, or in any other way. I defy the whole world of artists to reduce
the why and wherefore into a reasonable shape; one will declare that
"either" looks as if the individual was going to cry; the next critic will
say he sees nothing but a pleasant smile. "I should never have known who it
is if you hadn't told me," says a third; the next says "it's his eyes, but
not his nose;" and perhaps the next will say, "it's his nose, but not his
eyes."
I was present not long since at the showing a portrait, which I think about
the climax of doubt. "Not a bit like," was the first exclamation. The poor
artist sank into his chair; after, however, a brief contemplation, "It's
very like, _in-deed_; it's excellent:" this was said by a gentleman of the
highest attainments, and one of the best poets of the day.
Some persons (I beg pardon of the ladies) take the habiliments as the
standard of recognition. I do not accuse them of doing it wilfully; they do
not know it themselves. For example, Miss Smith will know Miss Jones a mile
or so off. By her general air, or her face? Oh no! It's by the bonnet she
helped her to choose at Madame What-d'ye-call's, because the colour suited
he complexion.
These are some of the mortifications attendant on artistic labour, and if
they occur with the educated classes, they are more likely to happen even
to "intelligent policemen," as the newspaper have it. If I dissent from the
plan it is because I doubt its efficiency, but do not deny that it is worth
a trial. If the French like to carry their portraits about with them on
their passports to show to policemen, let them submit to the humiliation. I
doubt very much whether the Chamber of Deputies would have made a law of
it: it appears a new idea in jurisprudence that a man _must_ sit for his
picture. Any one, however, understanding the camera, would be alive before
the removal of the cup of the lens, and be ready with a wry face; I do not
suppose he could be imprisoned for _that_.
Both plans are miserable travesties on the lovely uses of portrait painting
and photography. Side by side with Cowper's passionate address to his
mother's picture, how does it look?
"Oh, that those lips had language! Life has pass'd
With me but roughly since I saw thee last."
And,
"Blest be the art that can immortalise."
If photography has an advantage over canvas, it does indeed immortalise
(the painting may imitate, and the portrait may be good; but there is
something more profoundly affecting in having the actual, the real shade of
a friend perhaps long {507} since in his grave); and we ought not only to
be grateful to the illustrious inventors of the art, but prevent these base
uses being made of it.
In short, apart from the uncertainty of recognition, which I have not in
the least caricatured, if Giles Scroggins, housebreaker and coiner, and all
the swell mob, are to be photographed, it will bring the art into disgrace,
and people's friends will inquire delicately where it was done, when they
show their lively effigies. It may also mislead by a sharp rogue's
adroitness; and I question very much its legality.