DAVID ALAN PALMER
July 1933 - June 2000
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Christ’s College, Hendon Lane, Grammar School
Imperial College - physics, 1952 - 1955
Imperial College - PhD, 1958: supervisor W.D. Wright
National Physical Laboratory - 1958
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National Physical Laboratory - W.S. Stiles
NPL - general duties including photometry
NPL - Brian Crawford & colour rendering
NIC - chair of colour rendering committee 1965-7
IoO - Institute of Ophthalmology, 1967
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MESOPIC PHOTOMETRY
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MESOPIC PHOTOMETRY
“The equivalent luminance L of any light may be
expressed, to a good approximation, as a
function of its scotopic and photopic luminances.”
LP   E1( )  V ( )  d
LS   E 2 ( )  V '( )  d
The question is, “What is this function?”
David measured scotopic and photopic luminances
by matching test lights of different wavelengths to
white light of 2042K
At match, LV, the equivalent luminance follows the
relation:
LP  LV  LS
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and the scotopic and photopic luminances can be
calculated and log LP plotted against log LS
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David’s plot of log LP against log LS
Palmer said that ideally the plots should show,
“straight lines parallel to the P axis at very low
levels, and parallel to the S axis at high levels.”
But additivity was not perfect so there were
departures from this especially at the ends
of each curve.
The data fitted adequately
the expression:
MS  P 2
L(S, P ) 
MP
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which is the form that
the Palmer Mesopic
Model is usuall set out:
the figure shows how
well the data fit the
relation
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Data from other workers fitted the model well considering
the problems know to exist with additivity - here are data
from Kinney, JOSA, 58:1296, 1968
Christmas Celebrations
David was known for celebrating Christmas in style - a
chosen theme, usually Dickensian, was followed for food,
drink and decor
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and the lab had the benefit of last
years decorations, for example,
celebrations with Captain Cuttle
from Dombey and Son
In this David revealed high talent as
an artistic draughtsman
ENTOPTIC PHENOMENA - in art the light source was
seldom depicted because glare, halos and contrast ratios
are not easy or possible to capture convincingly
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A search for halos and glare showed many artists capturing
the drama of light and shade but hiding the source
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COLOUR RENDERING
This was the first of a
long series of papers
on colour rendering
and . . . .
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. . . the effects of new
fluorescent lamp
phosphors on clinical
evaluation of patients and
skin lesions
COLOUR RENDERING
And this was the
last set of papers
in the series
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COLOUR RENDERING
For this work the team were awarded the Walsh-Western
Bronze Medal of the Chartered Institute of Building Services
Engineers in 1993
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RETIREMENT
In the ninties David retired and then worked afternoons at
the University of Westminster
There we had fun with sunglare protection (i.e. sunglesses)
We evaluated sunglasses for
magazines and checked for safety a
whole range of toys which contained
laser light sources
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Traffic signal light recognition involved sorting out the
infamous Q Factor
and doing experiments on signal colour recognition
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CHRISTMAS again....and the sloe gin recipe competitions
continued as did the search for the perfect microwave
oven baked Christmas Pud
David continued his work, started with Brian Crawford
years before, on luminosity functions
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David showed normal observers’ photopic luminosity
functions for large fields fell into one of three groups
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David measured protanopes’ scotopic luminosity functions
and showed they were reduced at long wavelengths evidence that scotpic vision is a mix of rod and L wavelength
cone inputs
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David re-analysed the original scotopic luminosity function
data of Crawford which had been used to formulate the CIE
internationally agreed curve and found some surprises: many
curves were considerably narrower than the CIE curve and the
peak wavelengths were grouped as shown below
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David started to re-measure these curves with modern
equipment but had to know about pre-retinal absorption so we
set about measuring the macular pigment
We made many
prototypes with David’s
favourite material - card &
UHU glue
Six instruments of the final
design were made and are
used across Europe
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It was whilst calibrating
one of these that David
was taken ill - he never
worked again
PROMOTION OF SCIENCE
David hated the way the Government treated science and
scientists, and was appalled at the general lack of
understanding of science, especially by those “educated” elites
that made up various authorities
He worked to improve the understanding of science with, e.g.
the Institute of Physics and the Royal Institution
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James Clerk Maxwell - a model and hero
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DAVID PALMER vision scientist 1933-2000
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