The Sigma sd Quattro H uses the Sigma SA mount with a 1.35× crop factor (about 26.7 × 17.8 mm sensor). Below: equivalent focal lengths, maximum shutter speeds for sharp stars, a hyperfocal distance chart, compatible lenses and how to check the shutter count.
Mount
Sigma SA
Crop factor
1.35×
Sensor (approx.)
26.7 × 17.8 mm
Circle of confusion
0.0223 mm
Equivalent focal length & field of view
Lens focal length
Full-frame equivalent
Diagonal FOV
Horizontal FOV
8 mm
11 mm
127.0°
118.1°
10 mm
13 mm
116.1°
106.3°
12 mm
16 mm
106.4°
96.1°
14 mm
19 mm
97.8°
87.3°
16 mm
22 mm
90.2°
79.7°
18 mm
24 mm
83.4°
73.1°
20 mm
27 mm
77.5°
67.4°
24 mm
32 mm
67.5°
58.2°
28 mm
38 mm
59.6°
51.0°
35 mm
47 mm
49.3°
41.8°
50 mm
67 mm
35.6°
29.9°
85 mm
114 mm
21.4°
17.9°
135 mm
182 mm
13.6°
11.3°
200 mm
269 mm
9.2°
7.6°
300 mm
404 mm
6.1°
5.1°
400 mm
538 mm
4.6°
3.8°
600 mm
808 mm
3.1°
2.5°
Multiply by the 1.35× crop factor for the full-frame equivalent field of view.
Milky Way exposure: NPF and 500 rule
Focal length
NPF @ f/1.8
NPF @ f/2.8
Strict NPF @ f/2.8
500 rule
8 mm
22.5 s
26.9 s
14.5 s
46.4 s
10 mm
18.0 s
21.5 s
11.6 s
37.1 s
12 mm
15.0 s
17.9 s
9.7 s
31.0 s
14 mm
12.9 s
15.4 s
8.3 s
26.5 s
16 mm
11.2 s
13.4 s
7.3 s
23.2 s
18 mm
10.0 s
11.9 s
6.5 s
20.6 s
20 mm
9.0 s
10.8 s
5.9 s
18.6 s
24 mm
7.5 s
9.0 s
4.9 s
15.5 s
28 mm
6.4 s
7.7 s
4.2 s
13.3 s
35 mm
5.1 s
6.1 s
3.4 s
10.6 s
50 mm
3.6 s
4.3 s
2.4 s
7.4 s
NPF = (35 × f-number + 30 × pixel pitch) ÷ focal length, with a pixel pitch of 3.9 µm (typical for this format — exact resolution not in our database). The strict version (Michaud's detailed NPF for the galactic core) gives pin-point stars at 100% view; the 500 rule is a loose rule of thumb that shows trailing on modern sensors.
Hyperfocal distance chart
Focal length
f/2.8
f/5.6
f/8
f/11
f/16
10 mm
1.6 m
0.8 m
0.6 m
0.4 m
0.3 m
14 mm
3.2 m
1.6 m
1.1 m
0.8 m
0.6 m
16 mm
4.1 m
2.1 m
1.5 m
1.1 m
0.7 m
18 mm
5.2 m
2.6 m
1.8 m
1.3 m
0.9 m
20 mm
6.4 m
3.2 m
2.3 m
1.7 m
1.1 m
24 mm
9.2 m
4.6 m
3.3 m
2.4 m
1.6 m
28 mm
13 m
6.3 m
4.4 m
3.2 m
2.2 m
35 mm
20 m
9.8 m
6.9 m
5.0 m
3.5 m
50 mm
40 m
20 m
14 m
10 m
7.1 m
Focus at the hyperfocal distance and everything from half that distance to infinity is acceptably sharp (circle of confusion 0.0223 mm). Use the hyperfocal calculator for other settings.
Native and adapter-free compatible lenses from the Lensfun database. Third-party and adapted lenses may also work.
How to check the Sigma sd Quattro H shutter count
Not every maker writes a shutter count into image files. Try `exiftool -a -G1 -s image` on an unedited original and look for a tag containing "Shutter" or "Count".
ExifTool tag: (varies). Always test an original, unedited file straight from the card.
What is the crop factor of the Sigma sd Quattro H?
1.35×. A 24 mm lens frames like a 32 mm lens on full frame.
What shutter speed should I use for the Milky Way with the Sigma sd Quattro H?
With a 8 mm lens at f/2.8, about 27 seconds keeps stars sharp (NPF rule).
How do I check the shutter count on the Sigma sd Quattro H?
Not every maker writes a shutter count into image files. Try `exiftool -a -G1 -s image` on an unedited original and look for a tag containing "Shutter" or "Count".
Which lenses fit the Sigma sd Quattro H?
Lenses for the Sigma SA mount — 75 are listed above.
