854 
PLANIMETRIC MAP FROM SMALL FORMAT AERIAL 
PHOTOGRAPHS OF M К- 70 
LEGE 
£3 -- BUILDING 
FOOT PATH 
a • MANHOLE, COVERD » OPEN 
Til . WATER BODY 
^ Fig.1 
ROAD - 
ELECTRIC POLE . . . • . 
DITCH 
CONTROL POINT о 
Semi-Govt. Organisation. Pushpak is 2-seater high wing, 
light weight aircraft which is used for civil pilot training. 
This aircraft is suitable for hand-held camera as the doors 
could be easily taken out for ease in aerial photograohv. 
Another aircratt named REVATHI, again belonging to the 
Delhi Flying Club was also commissioned. A hole of about 
10 inches was opened in the belly of the aircraft just beh 
ind the co-pilots seat. (See Figure-1). A camera mount 
was fabricated which could hold Hasselblad camera 500 
EL/M or Hasselblad MK 70 (metric) camera. There is s 
provision tb give upto _+ 30 of correction for crab. 
2.3 Cameras 
Following table gives the information about the types of 
cameras used for the study. 35mm cameras were used in 
hand-held mode while Hasselblad was fixed in the mount 
(as described). 70mm camera with its film spool is quite 
heavy for hand-held and it is patently risky to venture it 
this way inspite of best precautions. Vertically of the h 
hand-held camera was judged visually. 
2.4 Films and filter combinations 
Several types of film-filter combinations were tried. All 
the films were commercially available as such, no storage 
problems were present. Table-2 provides information 
about the films etc. 
Exposed 70mm black and white films were processed in 
DK-50 developer using rewind equipment. 35mm colour . 
films were processed in commercially available automatic 
machines. Colour enlargements of 35mm were obtained 
on post-card size in the first instance for interpretation. 
2.5 Constraints - flying and season 
It was the month of July, 1985 when monsoon rains had 
just set in Delhi. There were, however, some spells of 
Table 1. Types of small format cameras used 
Slide-1 
huts. 
Camera 
make 
Format Focal 
Category length 
F 
num- 
be r 
Exposure Film Remarks 
meter advan 
cing 
colony 
. unauth 
plots c 
ASAHI 35mm 
PENTAX 
MX 
50mm 
1.4 
TTL 
Motor non- 
drive metric 
SLR 
east oi 
These 
to bui 
ASAHI 35mm 
PENTAX 
SPOTMATIC 
50mm 
1.4 
TTL 
Manu- non- 
al metric 
SLR 
operar 
struct! 
nent s 
NIKON 
35mm 
50mm 
1.4 
TTL 
Manu- non- 
a 1 metric 
SLR 
. conditi 
erosioi 
. progre 
NIKON 
35mm 
28mm 
2.8 
TTL 
Manu- non- 
a 1 metric 
SLR 
tructic 
. locatic 
Rohini 
HASSEL- 70mm 
BLAD 
500 EL/M 
80mm 
2.8 
Kodak Motor- non- 
aerial ised metric 
e xposure SLR 
meter 
. genera 
The Proje< 
and intens 
HASSEL 
BLAD 
MK-70 
70mm 
60pnm 
5.6 
Kodak Motor- metric 
aerial i sed 
exposure 
meter 
desired ph 
toring of 1 
zed that i 
foresaw le 
table evid' 
Table 2. 
Film/Filter/ExDOsure data 
3.1 Diffici 
Film 
make 
Film 
t>pe 
Film 
speed 
ISO 
Negative No. of Filter Exposure 
format expo- used settings 
sures 
. Mosaic 
a soft 
This a: 
Kodak 
colour 
Colour 100/21 w 
negatives 
24x36mm 36 
sky f/8 
light 1/500 sec. 
of his 
basic r 
Kodak 
colour 
200/24 
II 
II 
" f/8 
1/500 sec. 
of 'mi< 
'bug' i 
II 
II 
400/27 
II 
II 
" f/11 
1/500 sec. 
4. EXPER 
II 
II 
1000/30 
II 
It 
" f/16 
1/500 sec. 
SURVE' 
Sakura 
colour 
II 
100/21 
II 
II 
" f/11 
1/500 sec. 
Several re 
slum upgr; 
II 
200/24 
II 
II 
" f/8 
1/500 sec. 
get survey 
metry in \ 
Fuji 
colour 
II 
200/24 
It 
II 
" f/5,6,1/ 
500 sec. 
We used 
Agfa 
Superpar 
B&W 200/24 
Negatives 
II 
II 
~ f/16 
UV 1/200 sec. 
white film 
ives were 
Agfa- 
chrome 
Colour 
diaposi 
tives 
100/21 
II 
II 
" f/8 1/ 
500 sec. 
ing we go1 
ed on the 
Although, 
ILFORD B&W 400/27 
HP5 negatives 
56x56mm 100 
Yellow f/5,6,1/ 
500 sec. 
an accurac 
carry out 
ILFORD 
FP3 
200/24 55x55mm 80 
errors mot 
5. CONCL 
good weather in which aerial flying was possible. Rohini 
area comes within the funnel of approaching international 
airlines to Delhi airport. This gave us difficulties of gett 
ing flying clearance from control tower. In many cases, 
the base of clouds became our upper limit to which the 
aircraft could go although we desired to fly higher upto 
8000 feet to generate small scale pictures which will natu 
rally incorporate more area. 
A pleasant experience, however, was that SFAP could be 
done even in rainy season or cloudy days, if the flying 
height is kept anywhere from 500 feet to 3000 feet. Dur 
ing July, the cloud base, as given by Met. Office, genera 
lly stayed at 3000 feet. 
3. INTERPRETATION AND UTILISATION OF DATA 
Readable colour enlargements, upto 17 times, were made 
from 35mm negatives. These enlargements were studied 
for 
. encroachments on government land - several areas 
were marked 
. cluster of dweilings/temporary huts/slums 
The experi 
and the to 
this techm 
phenomenc 
nd. It is i 
be able to 
we advoca 
SFAP is 
can be prc 
The autf 
in photogr 
The autf 
earlier exp 
Bangkok b 
Prof.M. 3i 
River stud 
(12), and e 
Bandung, I