Evening star., 1936-03-15
NEW CAMERA EYE
A|DSFLASHPHOTOS
A. P. Chief Engineer Uses
PhotoeIeCtric Cell to
Regulate Shutter.
By the Associated Press.

By the Associated Press.
NEW YORK, March IA new type
of camera eye which takes the main
uncertainty out of fiashhght photog-
raphy was announced today by H. M.
Biele, chief engineer of the Associated
Press. 1t was worked out in the ASso-
ciated Press research and development
laboratory.
The trouble has been to have the
camera shutter open at the instant,
which the human eye cannot see, when
q binding flash is at its maximum.
This is solved by a photoelectric cell
speed flash synchroniZer.
The photoelectric cell, operating as
q real eye, is set in the photographer
reflector behind the flash bulb. The
cell sees the flash from behind.
Sees Rise of Flash.
1t sees what no living eye can and
what mechanical devices previously
have missed, the building up of the
flash. On the average, five-thou-
sandths of a second is required from
the beginning of the burning flash
until its light reaches a peak.
The photoelectric cell watches this
rising light. and sets off an electro
magnetic trigger which opens the
camera shutter at precisely the thou
sandth of a second of brightest light.
In 1000 trials the new eye has
never missed once. The best aver
age luck photographers have had in
catching this precious thousandth of
a second has been barely so per cent.
The source of the trouble is the
fact that flashlight bulbs cannot be
made to burn at exactly the same rate.
Some are slow by few thouSandthS
of second, others fast
The new eye treats each flash in
dividually, speeds up or holds back
the opening of the shutter. Mr..
Biele made the 1000 trials not only
on the best bulbs he could find. but
went back four years into old stocks,
TO get all the variations in bulbs that
came during the infancy of their
manufacture.
All Types of Bulbs Tested.
No kind of bulb escaped the vigi-
lance of the synchronizing eye.
A further advantage of the sensi-
tive cell is the fact that the mechan-
ical devices ordinarily used to open the
shutter at the time guessed at as the
maximum light were themselves sub
iect to delays.
One of the secrets of the new device
Is the ability of the eye to take into
account the lags in its own shutter
trigger and synchronize them. too.
The studies which have perfected
the synchronizer took four years.
When Mr.. Biele started, electrical ex-
perts said it appeared TO them impos-
sible to produce any device which
would "see" the rising light of five
thousandths Of second duration and
at the same time open a shutter be-
fore that brief interval was over.
The A. P. invention not only does
this, but takes only one-thousandth of
a second both to judge the light and
to open the shutter.
Offsh0ot of WirephOtO Service.
w. j. McCambridge, assistant gen.
eral manager of the Associated Press,
in an interview in Editor and Pub
Usher, says:
Although this marvellous invention
Is in reality an offshoot of the wire
photo service, it is primarily created
to perfect the quality of photos made
by A. P. photographers. The ultimate
object We aim for is perfect photog-
raphy and the utmost in transmits
sion"
Jack Price, writing in Editor and
Publisher, says:
This invention appears to be the
outstanding progressive contribution
to newspaper photography made in
the last decade"