Film SLR

Fujifilm GX680

The Fujifilm GX680 is a film slr that exposes a 56 × 56 mm frame on 6 × 6 cm film. Its crop factor is 0.55× — wider than full frame, so a 50 mm lens frames like 27 mm. Every number below is calculated for this exact film format.

6 × 6 cm film0.55× crop
Fujifilm GX680 camera
Photo: Viaissimo, CC BY-SA 3.0, via Wikimedia Commons
0.55×
Crop factor
56.0×56.0 mm
Image area
3136 mm²
Area · 363% of full frame

Specifications#

Model
GX680
Camera type
Film SLR
Film format
6 × 6 cm film
Image area
56.0 × 56.0 mm (6 × 6 cm film)
Crop factor
0.55×
Sensor type
Film
Viewfinder
waist-level
Exposure modes
Manual; aperture-priority automatic
Successor
GX680 II, GX680 III
Made in
Japan

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

Sensor size compared#

Fujifilm GX680Medium format 44 × 33 mmFull frame (35 mm)APS-C
The Fujifilm GX680 frame (highlighted) drawn to scale against common formats. Its area is 363% of a full-frame sensor.

Focal length equivalents & field of view#

Multiply any focal length by 0.55 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
21 mm11 mm106.3°106.3°124.1°
23 mm13 mm101.2°101.2°119.7°
28 mm15 mm90.0°90.0°109.5°
32 mm17 mm82.4°82.4°102.1°
35 mm19 mm77.3°77.3°97.1°
45 mm25 mm63.8°63.8°82.7°
55 mm30 mm54.0°54.0°71.5°
63 mm34 mm47.9°47.9°64.3°
80 mm44 mm38.6°38.6°52.7°
90 mm49 mm34.6°34.6°47.5°
110 mm60 mm28.6°28.6°39.6°
120 mm66 mm26.3°26.3°36.5°
150 mm82 mm21.1°21.1°29.6°
180 mm98 mm17.7°17.7°24.8°
250 mm137 mm12.8°12.8°18.0°
350 mm191 mm9.1°9.1°12.9°

Depth of field table#

Total depth of field at each subject distance, using a circle of confusion of 54.9 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
40 mmf/1.82.8 cm11.9 cm49.2 cm1.14 m3.38 m19.8 m16.2 m
40 mmf/2.84.4 cm18.6 cm78.1 cm1.86 m6.17 m228 m10.4 m
40 mmf/46.3 cm26.8 cm1.16 m2.92 m12.7 m∞7.32 m
40 mmf/812.8 cm56.7 cm3.03 m14.4 m∞∞3.68 m
79 mmf/1.80.7 cm2.9 cm12.2 cm27.8 cm78.4 cm3.22 m63.2 m
79 mmf/2.81.0 cm4.5 cm19.0 cm43.4 cm1.23 m5.20 m40.7 m
79 mmf/41.5 cm6.5 cm27.2 cm62.3 cm1.79 m7.95 m28.5 m
79 mmf/83.0 cm13.0 cm55.1 cm1.29 m3.94 m27.3 m14.3 m
134 mmf/1.80.2 cm1.0 cm4.1 cm9.5 cm26.8 cm1.09 m182 m
134 mmf/2.80.3 cm1.5 cm6.4 cm14.7 cm41.7 cm1.70 m117 m
134 mmf/40.4 cm2.1 cm9.1 cm21.1 cm59.7 cm2.45 m81.9 m
134 mmf/80.9 cm4.2 cm18.3 cm42.3 cm1.21 m5.13 m41.0 m
221 mmf/1.80.1 cm0.3 cm1.4 cm3.4 cm9.7 cm39.6 cm494 m
221 mmf/2.80.1 cm0.5 cm2.2 cm5.2 cm15.0 cm61.6 cm318 m
221 mmf/40.1 cm0.7 cm3.2 cm7.5 cm21.5 cm88.1 cm223 m
221 mmf/80.3 cm1.4 cm6.4 cm15.0 cm43.1 cm1.77 m111 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 79 mm
f/1.2f/0.794.8 m
f/1.4f/0.881.3 m
f/1.8f/1.063.2 m
f/2f/1.156.9 m
f/2.8f/1.540.7 m
f/4f/2.228.5 m
f/5.6f/3.120.4 m
f/8f/4.414.3 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
26 mm (14 mm eq.)35.2 s
37 mm (20 mm eq.)24.7 s
44 mm (24 mm eq.)20.8 s
64 mm (35 mm eq.)14.3 s
92 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
44 mm1/25 s0.3 s1.3 s
92 mm1/50 s1/6 s0.6 s
183 mm1/100 s1/13 s0.3 s
366 mm1/200 s1/25 s1/6 s

Frequently asked questions#

What is the crop factor of the Fujifilm GX680?

The Fujifilm GX680 has a crop factor of 0.55× relative to 35 mm full frame (diagonal 79.2 mm vs 43.3 mm).

What size is the Fujifilm GX680 frame?

56.0 × 56.0 mm (6 × 6 cm film), an area of 3136 mm² — 363% of full frame.

How long can I expose the night sky with the Fujifilm GX680?

With a 37 mm lens (20 mm equivalent) the 500 rule gives 25 s.

Sources & licences#

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