Sony a6400 crop factor: 1.53×
The a6400 is Sony’s best-selling APS-C body for stills and hybrid shooters, and the camera most people mean when they ask about the "Sony crop factor". Its 23.5 × 15.6 mm sensor has a 28.21 mm diagonal, so lenses frame 1.53× tighter than on full frame.
A 30 mm lens on APS-C (1.53× crop) frames like a 46 mm lens on full frame. At f/1.4 it gives the depth of field of about f/2.1 there — but exposure stays the same as f/1.4.
- Horizontal field of view
- 42.8°
- Vertical field of view
- 29.1°
- Crop ratio
- 1.53×
- Sensor size
- 23.5 × 15.6 mm
Full-frame equivalent of a 30 mm f/1.4 lens on each format
| Sensor | Focal length | Aperture (DoF) |
|---|---|---|
| Full frame | 30 mm | f/1.4 |
| APS-C (1.5×) | 46 mm | f/2.1 |
| Canon APS-C (1.6×) | 48 mm | f/2.3 |
| Micro Four Thirds | 60 mm | f/2.8 |
| 1-inch | 82 mm | f/3.8 |
| Medium format (44×33) | 24 mm | f/1.1 |
| Phone main camera (1/1.3″) | 106 mm | f/4.9 |
Sensor size and crop factor
Crop factor is the full-frame diagonal (43.27 mm) divided by the sensor diagonal. For the a6400: √(23.5² + 15.6²) = 28.21 mm, and 43.27 ÷ 28.21 = 1.53.
| Property | Value |
|---|---|
| Sensor size | 23.5 × 15.6 mm |
| Diagonal | 28.21 mm |
| Crop factor (computed) | 1.53× |
| Crop factor quoted by the maker | 1.5× |
| Area vs full frame | 42% |
| Circle of confusion (diagonal ÷ 1443) | 0.020 mm |
| Resolution / pixel pitch | 24.2 MP · 3.89 µm |
| Lens mount | Sony E |
Source: Sony specifications: "APS-C type (23.5 × 15.6 mm) Exmor CMOS sensor", 24.2 effective megapixels.
Equivalent focal length and aperture for Sony E lenses
The full-frame equivalent is the focal length × 1.53. The DoF-equivalent aperture (f-number × 1.53) describes depth of field and total light at the same framing; exposure — shutter speed and ISO — is set by the real f-number as usual. Hyperfocal distances use a 0.020 mm circle of confusion.
| Lens | Focal length | Full-frame equivalent | Max aperture | DoF-equivalent aperture | Horizontal view | Hyperfocal at f/8 |
|---|---|---|---|---|---|---|
| Sony E PZ 16–50mm f/3.5–5.6 OSS (kit)at 16 mm | 16 mm | 24.5 mm | f/3.5 | f/5.4 | 72.6° | 1.62 m5.30 ft |
| Sony E PZ 16–50mm f/3.5–5.6 OSS (kit)at 50 mm | 50 mm | 76.5 mm | f/5.6 | f/8.6 | 26.4° | 15.7 m51.4 ft |
| Sony E 18–135mm f/3.5–5.6 OSSat 18 mm | 18 mm | 27.5 mm | f/3.5 | f/5.4 | 66.3° | 2.04 m6.70 ft |
| Sony E 18–135mm f/3.5–5.6 OSSat 135 mm | 135 mm | 207 mm | f/5.6 | f/8.6 | 9.9° | 114 m374 ft |
| Sony E 11mm f/1.8 | 11 mm | 16.8 mm | f/1.8 | f/2.8 | 93.8° | 77 cm2.52 ft |
| Sigma 16mm f/1.4 DC DN Contemporary | 16 mm | 24.5 mm | f/1.4 | f/2.1 | 72.6° | 1.62 m5.30 ft |
| Sony E 35mm f/1.8 OSS | 35 mm | 53.6 mm | f/1.8 | f/2.8 | 37.1° | 7.69 m25.2 ft |
| Sigma 30mm f/1.4 DC DN Contemporary | 30 mm | 45.9 mm | f/1.4 | f/2.1 | 42.8° | 5.66 m18.6 ft |
| Sigma 56mm f/1.4 DC DN Contemporary | 56 mm | 85.7 mm | f/1.4 | f/2.1 | 23.7° | 19.7 m64.5 ft |
| Sony FE 50mm f/1.8 (full-frame lens) | 50 mm | 76.5 mm | f/1.8 | f/2.8 | 26.4° | 15.7 m51.4 ft |
| Sony FE 85mm f/1.8 (full-frame lens) | 85 mm | 130 mm | f/1.8 | f/2.8 | 15.7° | 45.2 m148 ft |
What is different about the a6400
Sony rounds the APS-C crop factor to 1.5×, but the a6400’s published 23.5 × 15.6 mm sensor works out at 1.53×. For everyday framing the difference is invisible; it only shows up when you compare exact equivalents, which is why the tables below look a little "longer" than the 1.5× numbers printed in many lens reviews.
The a6400 has no in-body image stabilisation, so the "OSS" (Optical SteadyShot) lenses matter for slow shutter speeds, and the old handholding rule should use the equivalent focal length: about 1/80 s with the 50 mm end of the kit zoom. The three Sigma f/1.4 primes (16, 30 and 56 mm) are the classic upgrade path because they give roughly the field of view of 24, 46 and 86 mm full-frame lenses with the background blur of about f/2.1.
FAQ
What is the crop factor of the Sony a6400?
1.53×. The 23.5 × 15.6 mm sensor has a 28.21 mm diagonal, and 43.27 ÷ 28.21 = 1.53. The maker rounds it to 1.5×.
What is the full-frame equivalent of the Sony E PZ 16–50mm f/3.5–5.6 OSS?
24–77 mm in field of view, with the depth of field of about f/5.4–f/8.6 on full frame. Exposure does not change: f/3.5 still needs the same shutter speed and ISO as f/3.5 on any camera.
What does the Sigma 30mm f/1.4 DC DN Contemporary equal on full frame?
About 46 mm f/2.1: the field of view of a 46 mm lens and the depth of field of f/2.1 on full frame. Its hyperfocal distance at f/8 on the a6400 is 5.66 m (18.6 ft).
Can I use full-frame FE lenses on the a6400?
Yes. FE lenses mount directly on every E-mount body and simply frame 1.53× tighter, so the FE 50mm f/1.8 behaves like a 77 mm portrait lens. They are larger than APS-C lenses of the same field of view, but the FE 85mm f/1.8 is a popular, affordable telephoto portrait option on the a6400.
Other cameras
- Sony a670023.3 × 15.5 mm · 1.55× crop
- Sony ZV-E1023.5 × 15.6 mm · 1.53× crop
- Canon EOS R5022.3 × 14.9 mm · 1.61× crop
- Canon EOS R1022.3 × 14.9 mm · 1.61× crop
- Nikon Z5023.5 × 15.7 mm · 1.53× crop
- Fujifilm X-T523.5 × 15.6 mm · 1.53× crop
- Panasonic Lumix G9 II17.3 × 13 mm · 2.00× crop
- Sony RX100 series13.2 × 8.8 mm · 2.73× crop
- iPhone 17 Pro main camera≈ 10.0 × 7.5 mm · 3.46× crop
More on the APS-C format — depth of field, hyperfocal and star charts — on the APS-C (1.5×) sensor page. The theory is in crop factor explained.