Film rangefinder

Ducati Sogno

The Ducati Sogno is a film rangefinder that exposes a 24 × 18 mm frame on Half-frame 35 mm film. Its crop factor is 1.44×, so a 50 mm lens frames like 72 mm on full frame. Every number below is calculated for this exact film format.

Half-frame 35 mm film1.44× crop
Ducati Sogno camera
Photo: Izaakb at English Wikipedia, Public domain, via Wikimedia Commons
1.44×
Crop factor
24.0×18.0 mm
Image area
432 mm²
Area · 50% of full frame

Specifications#

Brand
Ducati
Model
Sogno
Camera type
Film rangefinder
Film format
Half-frame 35 mm film
Image area
24.0 × 18.0 mm (Half-frame 35 mm film)
Crop factor
1.44×
Fastest shutter
1/500 s
Focus
manual
Exposure modes
manual
Shutter
focal-plane
Made in
Bologna, Italy

Specifications merged from Wikipedia and Wikidata. Spot an error? Tell us.

Sensor size compared#

Medium format 44 × 33 mmFull frame (35 mm)Ducati SognoAPS-CFour Thirds / Micro Four Thirds1" (one-inch) sensor
The Ducati Sogno frame (highlighted) drawn to scale against common formats. Its area is 50% of a full-frame sensor, which collects about 1.0 stops less total light at the same exposure.

Focal length equivalents & field of view#

Multiply any focal length by 1.44 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
8 mm12 mm112.6°96.7°123.9°
10 mm14 mm100.4°84.0°112.6°
12 mm17 mm90.0°73.7°102.7°
14 mm20 mm81.2°65.5°93.9°
16 mm23 mm73.7°58.7°86.3°
18 mm26 mm67.4°53.1°79.6°
20 mm29 mm61.9°48.5°73.7°
24 mm35 mm53.1°41.1°64.0°
28 mm40 mm46.4°35.6°56.4°
35 mm50 mm37.8°28.8°46.4°
40 mm58 mm33.4°25.4°41.1°
50 mm72 mm27.0°20.4°33.4°
56 mm81 mm24.2°18.3°30.0°
70 mm101 mm19.5°14.7°24.2°
85 mm123 mm16.1°12.1°20.0°
100 mm144 mm13.7°10.3°17.1°
135 mm195 mm10.2°7.6°12.7°
200 mm288 mm6.9°5.2°8.6°
300 mm433 mm4.6°3.4°5.7°
400 mm577 mm3.4°2.6°4.3°
600 mm865 mm2.3°1.7°2.9°
800 mm1154 mm1.7°1.3°2.1°

Depth of field table#

Total depth of field at each subject distance, using a circle of confusion of 20.8 µm (the 0.030 mm full-frame standard scaled by the crop factor). Detailed tables: 24 mm f/1.8, 24 mm f/2.8, 35 mm f/1.8, 35 mm f/2.8, 50 mm f/1.8, 50 mm f/2.8.

FocalAperture50.0 cm1.00 m2.00 m3.00 m5.00 m10.0 mHyperfocal
15 mmf/1.88.1 cm33.7 cm1.48 m3.96 m26.6 m∞6.02 m
15 mmf/2.812.8 cm54.5 cm2.79 m11.5 m∞∞3.88 m
15 mmf/418.5 cm84.0 cm6.37 m∞∞∞2.72 m
15 mmf/841.2 cm3.10 m∞∞∞∞1.37 m
30 mmf/1.82.0 cm8.1 cm33.0 cm75.3 cm2.16 m10.0 m24.1 m
30 mmf/2.83.0 cm12.6 cm51.8 cm1.20 m3.59 m22.1 m15.5 m
30 mmf/44.4 cm18.1 cm75.3 cm1.78 m5.82 m123 m10.8 m
30 mmf/88.8 cm37.1 cm1.68 m4.72 m59.1 m∞5.44 m
51 mmf/1.80.6 cm2.7 cm11.2 cm25.5 cm71.6 cm2.92 m69.5 m
51 mmf/2.81.0 cm4.3 cm17.5 cm39.8 cm1.12 m4.69 m44.7 m
51 mmf/41.4 cm6.1 cm25.0 cm57.1 cm1.62 m7.08 m31.3 m
51 mmf/82.9 cm12.2 cm50.7 cm1.17 m3.52 m21.4 m15.7 m
84 mmf/1.80.2 cm1.0 cm4.1 cm9.3 cm26.1 cm1.06 m189 m
84 mmf/2.80.3 cm1.5 cm6.3 cm14.5 cm40.6 cm1.65 m121 m
84 mmf/40.5 cm2.2 cm9.0 cm20.7 cm58.2 cm2.37 m84.9 m
84 mmf/81.0 cm4.3 cm18.1 cm41.5 cm1.18 m4.95 m42.5 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 30 mm
f/1.2f/1.736.1 m
f/1.4f/2.030.9 m
f/1.8f/2.624.1 m
f/2f/2.921.7 m
f/2.8f/4.015.5 m
f/4f/5.810.8 m
f/5.6f/8.17.76 m
f/8f/11.55.44 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
10 mm (14 mm eq.)34.7 s
14 mm (20 mm eq.)24.8 s
17 mm (25 mm eq.)20.4 s
24 mm (35 mm eq.)14.4 s
35 mm (50 mm eq.)9.9 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
17 mm1/25 s0.3 s1.3 s
35 mm1/50 s1/6 s0.6 s
69 mm1/100 s1/13 s0.3 s
139 mm1/200 s1/25 s1/6 s

Frequently asked questions#

What is the crop factor of the Ducati Sogno?

The Ducati Sogno has a crop factor of 1.44× relative to 35 mm full frame (diagonal 30.0 mm vs 43.3 mm).

What size is the Ducati Sogno frame?

24.0 × 18.0 mm (Half-frame 35 mm film), an area of 432 mm² — 50% of full frame.

How long can I expose the night sky with the Ducati Sogno?

With a 14 mm lens (20 mm equivalent) the 500 rule gives 25 s.

Sources & licences#

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

Last posts

  1. Thoughtful Retirement Gifts for New Photographers
  2. Should You Choose Retailers With Long Return Windows
  3. Can a Used Lens Be Dropped Without Visible Damage
  4. Can a Cheap UV Filter Ruin Sharp Lens Performance
  5. Photography Books vs Accessories for Beginners
  6. Best Gifts for Photographers Under Twenty Dollars
  7. Camera Insurance vs Home Insurance Which One Do You Need
  8. Best Graduation Gifts for Photographers and Their Gear
  9. Best Christmas Gifts for New Mirrorless Camera Owners
  10. Best Birthday Gifts for New Photographers and Why They Work