mirror stereoscopes, A 7, and Balplex. The measurements were made
on the original negatives and diapositives for Balplex respectively.
RIO
Model 41 (A — 1880 m, no shadows).
As in measuring in mirror stereoscope and micrometer, measuring
the tree tops proved difficult. The systematic errors were great for all
instruments, particularly Balplex and A 7 (both — 4.9). Also as re-
gards the standard deviation the lowest result (-- 2.03 m) was obtained
in A 7.
Table 5. Systematic Error and Standard Deviation in Measuring on Negatives and
Diapositives for Balplex. Figures in Brackets — Contact Copies (15a) or Enlarg-
ed. Prints, Scale 1:10 000 (410).
|
|41 A + 1880 m'4lo A = 1890 m | 15a À = 8120 m
Overcast Clear Clear
|
at | — |
‚System. Standard System. Standard System. | Standard
Interpreter |
p error, m, dev., m error, m | dev., m | dev., m
Mirror RE — 9.9 | + 1.46 + 0.0
+ 1.30 | (— 3.5) | (+ 0.50)
(— 0.1) | (+ 0.43)
magnification 8x ..|2|, —3.5 | + 1.62) +03 | 2133 | (— 1.1) | (2- 2.02)
{+ 00) | (> 1.50)
Bolpler::. vues: Jini — 4.9 | = 1.98/ — 01 | +106 —23.| +134
47. iid — 49 | =203| +04 | + 0.29 | —15 | £097
Model 410 (A = 1890 m, shadows).
Table 5 shows very high values for all instruments. As regards the
measurements in mirror stereoscope an examination of the individual
results shows that the explanation is to be found in some extremely
high values, probably due to wrong stereo-effect. In measuring in Bal-
plex and A 7 these extreme values were not found. The explanation of
the high values for these instruments seems to be a slightly too large
machine scale. The lowest standard deviation is found in A 7 (== 0.24
m); Balplex (== 1.06), mirror stereoscope (= 1.30 and — 1.13).
Model 15a (A = 3 120 m, shadows)
The measurements were made only in Balplex and A 7. In measur-
ing in Balplex difficulties were encountered due to unsharpness.
According to the interpreter some of the trees were so unsharp that no
real measuring was possible.
Discussion of the Results of the Measurements
The results of the measurements performed on the prints without
shadows by means of different instruments show the same tendency in
9
Sta
TR SR FT AGERE
