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multiple exposure sequence - technical details
The following is a detailed summary of the equipment and exposures used to create this multiple exposure sequence of the 2002 Total Solar Eclipse.
Event
- Total solar eclipse, 4th December 2002.
Location
- Near Lake Everard, South Australia
(31o 25.95' South, 135o 21.24' East)
Equipment
- Pentax 645 medium format camera
- 150 mm Pentax A f/3.5 lens (φ = 58mm, field of view = 17o x 23o)
- Manfrotto tripod with weight bags (filled with sand)
- Cable release
- Hand held spot meter
- Darkroom timer
Film
- Fuji Velvia ISO 50 transparency (120 roll film)
Filters
- Hoya ND 400 (+8 stops)
- Hoya ND 8 (+3 stops)
- Hoya ND 4 (+2 stops)
Total = +13 stops (equivalent to 4.0 ND, filter factor = 104, but visually unsafe)
Exposures
The table below shows the times and corresponding exposures:
Event |
Time (ACST) |
Shutter Speed |
Aperture |
Notes |
1st contact |
18:41:29 |
- |
- |
|
|
18:55:55 |
- |
- |
Sun placed in top corner of frame |
1st photo |
19:05:55 |
1/250 |
f/22-32 |
|
|
19:10:55 |
1/250 |
f/22-32 |
|
|
19:15:55 |
1/250 |
f/22-32 |
|
|
19:20:55 |
1/250 |
f/22-32 |
|
|
19:25:55 |
1/250 |
f/22 |
|
|
19:30:55 |
1/250 |
f/16-22 |
1/2 stop increase |
|
19:35:55 |
1/250 |
f/16 |
1 stop increase |
Totality |
19:40:55 |
1/4 |
f/3.5-5.6 |
No filter |
|
19:45:55 |
1/250 |
f/11-16 |
1 stop increase |
|
19:50:55 |
1/250 |
f/11-16 |
1/2 stop increase |
|
19:55:55 |
1/250 |
f/11 |
|
|
20:00:55 |
1/250 |
f/8 |
|
|
20:05:55 |
1/250 |
f/5.6 |
|
|
20:10:55 |
1/125 |
f/5.6 |
|
Last photo |
20:15:55 |
1/30 |
f/5.6-8 |
|
Sunset |
20:21:00 |
- |
- |
|
Sky exposure |
20:24:00 |
1/500 |
f/11 |
No filter |
Notes
- At 18:55:55 the Sun was placed in the top right corner of the viewfinder to allow it to track into frame before the first exposure. This was practised beforehand.
- The 1/2 stop and 1 stop increases in exposure around totality were made to compensate for solar limb darkening.
- A spot meter reading taken on the horizon during totality suggested an exposure of roughly 1/2 sec at f/5.6, however the actual exposure used (1/4 sec at f/3.5-5.6) was chosen in advance, making it about 1 1/2 stops under what the meter reading suggested.
- The sky exposure, made after sunset, was taken at 4 stops under the meter reading and probably did not contribute much to the overall image. Most of the colour in the sky was therefore formed during the totality shot.
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