Compact

Canon Digital IXUS 55

The Canon Digital IXUS 55 is a compact with a 1/2.5" sensor measuring 5.7 × 4.3 mm. Its crop factor is 6.05×, so a 50 mm lens frames like 303 mm on full frame. Every number below is calculated for this exact sensor.

1/2.5"6.05× crop
6.05×
Crop factor
5.7×4.3 mm
Sensor size
24 mm²
Area · 3% of full frame

Specifications#

Brand
Canon
Model
Digital IXUS 55
Also known as
Canon PowerShot SD450, IXUS 55, PowerShot SD450
Camera type
Compact
Sensor size
5.7 × 4.3 mm (1/2.5" sensor)
Crop factor
6.05×

Specifications merged from Wikidata, Lensfun and openMVG. Spot an error? Tell us.

Sensor size compared#

1/2.3" sensorCanon Digital IXUS 55
The Canon Digital IXUS 55 sensor (highlighted) drawn to scale against common formats. Its area is 3% of a full-frame sensor, which collects about 5.1 stops less total light at the same exposure.

Focal length equivalents & field of view#

Multiply any focal length by 6.05 to get the full-frame field of view. For fixed-lens cameras use the real focal length printed on the lens (e.g. “6.1–18.3 mm”), not the 35 mm equivalent.

Lens on this cameraFull-frame equivalentHorizontalVerticalDiagonal
4 mm24 mm71.3°56.1°83.6°
4.5 mm27 mm65.1°50.7°76.9°
5 mm30 mm59.7°46.1°71.1°
6 mm36 mm51.1°39.1°61.6°
8 mm48 mm39.5°29.8°48.1°
10 mm61 mm32.0°24.0°39.3°
12 mm73 mm26.9°20.1°33.2°
15 mm91 mm21.7°16.2°26.8°
20 mm121 mm16.3°12.2°20.3°
25 mm151 mm13.1°9.7°16.3°
30 mm182 mm10.9°8.1°13.6°
40 mm242 mm8.2°6.1°10.2°
50 mm303 mm6.6°4.9°8.2°
70 mm424 mm4.7°3.5°5.8°
100 mm605 mm3.3°2.4°4.1°
150 mm908 mm2.2°1.6°2.7°

Depth of field table#

Total depth of field at each subject distance, using a circle of confusion of 5.0 µm (the 0.030 mm full-frame standard scaled by the crop factor).

FocalAperture50.0 cm1.00 m2.00 m3.00 m5.00 m10.0 mHyperfocal
4 mmf/233.9 cm1.99 m∞∞∞∞1.62 m
4 mmf/2.852.8 cm6.81 m∞∞∞∞1.16 m
4 mmf/498.8 cm∞∞∞∞∞81.1 cm
4 mmf/8∞∞∞∞∞∞40.8 cm
7 mmf/210.1 cm41.9 cm1.93 m5.74 m∞∞4.95 m
7 mmf/2.814.2 cm61.1 cm3.31 m18.1 m∞∞3.54 m
7 mmf/420.8 cm95.8 cm9.22 m∞∞∞2.48 m
7 mmf/847.4 cm4.54 m∞∞∞∞1.24 m
12 mmf/23.4 cm13.7 cm55.8 cm1.29 m3.89 m26.1 m14.5 m
12 mmf/2.84.7 cm19.2 cm79.6 cm1.88 m6.25 m262 m10.4 m
12 mmf/46.7 cm27.7 cm1.18 m2.97 m13.0 m∞7.28 m
12 mmf/813.7 cm58.8 cm3.13 m15.3 m∞∞3.64 m
20 mmf/21.2 cm4.9 cm19.7 cm44.6 cm1.25 m5.27 m40.4 m
20 mmf/2.81.7 cm6.8 cm27.6 cm62.7 cm1.78 m7.87 m28.8 m
20 mmf/42.4 cm9.7 cm39.6 cm90.6 cm2.63 m13.1 m20.2 m
20 mmf/84.8 cm19.6 cm81.7 cm1.94 m6.53 m928 m10.1 m

Equivalent aperture#

Exposure is identical at the same f-number on any format; equivalence only describes depth of field and total light.

Aperture on this cameraFull-frame equivalent (depth of field)Hyperfocal at 7 mm
f/1.2f/7.38.25 m
f/1.4f/8.57.07 m
f/1.8f/10.95.50 m
f/2f/12.14.95 m
f/2.8f/16.93.54 m
f/4f/24.22.48 m
f/5.6f/33.91.77 m
f/8f/48.41.24 m

Night-sky exposure limits#

Longest exposure before stars trail. The NPF rule accounts for pixel pitch and is stricter than the classic 500 rule — use it for pin-sharp stars on high-resolution sensors. (NPF needs a known resolution and is omitted here.)

Focal length500 rule
4 mm (24 mm eq.)20.7 s
5 mm (30 mm eq.)16.5 s
6 mm (36 mm eq.)13.8 s
7 mm (42 mm eq.)11.8 s
8 mm (48 mm eq.)10.3 s

Open the NPF / 500 rule calculator →

Handheld shutter speed guide#

The reciprocal rule uses the equivalent focal length. High-resolution sensors may need one stop faster than this for pixel-sharp results.

Focal lengthNo stabilisation (1/equiv. focal)With 3-stop ISWith 5-stop IBIS
4 mm1/25 s0.3 s1.3 s
8 mm1/50 s1/6 s0.6 s
17 mm1/100 s1/13 s0.3 s
33 mm1/200 s1/25 s1/6 s

Lens#

The Canon Digital IXUS 55 has a built-in, non-interchangeable lens. Use the real focal length of that lens with the tables above; its full-frame equivalent is that number × 6.05.

Frequently asked questions#

What is the crop factor of the Canon Digital IXUS 55?

The Canon Digital IXUS 55 has a crop factor of 6.05× relative to 35 mm full frame (diagonal 7.1 mm vs 43.3 mm).

What size is the Canon Digital IXUS 55 sensor?

5.7 × 4.3 mm (1/2.5"), an area of 24 mm² — 3% of full frame.

Is the Canon Digital IXUS 55 full frame?

No — its sensor is 1/2.5", which is 35.3× smaller in area than full frame.

How long can I expose the night sky with the Canon Digital IXUS 55?

With a 5 mm lens (30 mm equivalent) the 500 rule gives 17 s.

Sources & licences#

Last updated October 03, 2026 · How we calculate · Sources

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