Olympus VANOX-T - Page 40

6. Large format photomicrography at film speed settings lower than ISO 64
‘The Model AHMT principally permits the film speed settings as low as ISO 64 for large format photography,
which, however, can be further extended to ISO 6 by means of manual exposure adjustment and by use of the
built-in NO filters,
1) In the case of film speed settings at ISO 50, 40 and 32 Fosse)
‘These low film speeds can be obtained by setting the expo- 18050 0
sure adjustment button as follows: Press the film speed
button to ISO 64 (see p. 20), and then press the exposure 18030. en
adjustment button (p. 19) to manually set the exposure time 150 32 050
according to the desired film speed as given in Table 1
Table 1
2) In the case of film speed settings at ISO 25, 12 and 6
These further lower speeds can be obtained in the following
2 methods: (A) by use of the builtin NO filters, and (8) by
means of manual exposure adjustment. ®
A By the builtin ND filters
1) Press the exposure adjustment button to ISO 60 as men 19025 NEE
tioned above.
2) Press the AE (auto exposure) lock button |
3) Adjust the light intensity control knob (p. 7) to engage 506 [3 full stops over
the
builtin
ND
filter
according
to
the
film
speed
as
given
Table2
in Table 2.
150 12 2 full stops over
B. Manual exposure adjustment
1) Press the exposure adjustment button to ISO 5035 men.
tioned above.
2) Press the MANUAL button (p. 16) in the followingman. |_!S025 i
ner: Read out the estimated exposure time displayed on 13012 | ax
the indication panel on auto exposure mode, prior to вов | ax
pressing the MANUAL button; then multiply the esti
mated exposure time by the exposure factor obtained
from Table 3, and expose on Manual mode.
Table 3
# Gonerally speaking, large format photomicrography involves the lens-and-film plane distance longer than 35 mm
photomicrography, which reduces the light amount to reach the film plane. On the other hand, it is possible for
the large format film to obtain a sharper photograph. Accordingly a high speed film is recommended for large
format photomicrography as much as possible