What is the crop factor of the Pentax 645D?
The Pentax 645D is equipped with a medium format sensor, whose diagonal measures 55mm. The sensor has a crop factor (or format factor, or focal length multiplier) of 0.79.
The crop factor is defined as the ratio of the 35mm full-frame film diagonal to the diagonal of a digital sensor. This number indicates how a lens behaves in relation to the size of the image sensor.
Sensor size comparison with a film slide
With a crop factor of 0.79, the sensor in the Pentax 645D is larger than the receptor area of a 35mm film slide or negative. As a result, a lens that is attached to the Pentax 645D will offer a wider angle of view and provide shallower depth of field than a lens of similar focal length and aperture on a film camera. The equivalent focal length is obtained by multiplying the actual focal length of the lens with the crop factor. For example, a 63mm lens on the Pentax 645D will provide the same angle of view and depth of field as a 50mm normal lens on a film camera (63mm * 0.79 = 50mm).
Sensor specs and performance
The table below compares the sensor specs of the Pentax 645D to those of several similar cameras. The reported DXO values are indicators of the sensor's imaging quality (higher is better), covering color depth (DXO Portrait), dynamic range (DXO Landscape), and high-ISO noise (DXO Sports). Larger sensor cameras tend to outperform cameras of the same generation that are equipped with a smaller imager. On the other hand, larger sensors are more expensive and require bigger and heavier lenses than smaller light receptors.
| Camera Model |
Sensor Class |
Resolution (MP) |
Horiz. Pixels |
Vert. Pixels |
Video Format |
DXO Portrait |
DXO Landscape |
DXO Sports |
DXO Overall |
||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1. | Pentax 645D | Medium Format | 39.5 | 7264 | 5440 | none | 24.6 | 12.6 | 1262 | 82 | |
| 2. | Canon 1D X Mark II | Full Frame | 20.0 | 5472 | 3648 | 4K/60p | 24.1 | 13.5 | 3207 | 88 | |
| 3. | Canon 1D X | Full Frame | 17.9 | 5184 | 3456 | 1080/30p | 23.8 | 11.8 | 2786 | 82 | |
| 4. | Canon 1D Mark IV | APS-H | 16.0 | 4896 | 3264 | 1080/30p | 22.8 | 12.0 | 1320 | 74 | |
| 5. | Leica S Typ 006 | Medium Format | 37.5 | 7500 | 5000 | none | 23.9 | 12.2 | 824 | 76 | |
| 6. | Nikon D850 | Full Frame | 45.4 | 8256 | 5504 | 4K/30p | 26.4 | 14.8 | 2660 | 100 | |
| 7. | Nikon D5 | Full Frame | 20.7 | 5588 | 3712 | 4K/30p | 25.1 | 12.3 | 2343 | 88 | |
| 8. | Nikon D810 | Full Frame | 36.2 | 7360 | 4912 | 1080/60p | 25.7 | 14.8 | 2853 | 97 | |
| 9. | Nikon D3S | Full Frame | 12.1 | 4256 | 2832 | 720/24p | 23.5 | 12.0 | 3253 | 82 | |
| 10. | Pentax 645Z | Medium Format | 51.1 | 8256 | 6192 | 1080/60i | 26.0 | 14.7 | 4505 | 101 | |
| 11. | Sony A7R | Full Frame | 36.2 | 7360 | 4912 | 1080/60p | 25.6 | 14.1 | 2746 | 95 |
In the United States, the 645D was initially launched in March 2010 at a price of $9,995.
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Camera to camera comparisons
If you would like to see a side-by-side review with another camera, just make your choice using the following search menu. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.
| Camera Model | Pentax 645D | |
| Camera Type | Digital single lens reflex | |
| Camera Lens | Pentax 645 mount lenses | |
| Launch Date | March 2010 | |
| Launch Price | USD 9 995 | |
| Sensor Specs | ||
|---|---|---|
| Sensor Technology | CCD | |
| Sensor Format | Medium Format Sensor | |
| Sensor Size | 44.0 x 33.0 mm | |
| Sensor Area | 1 452 mm2 | |
| Sensor Diagonal | 55 mm | |
| Crop Factor | 0.79x | |
| Sensor Resolution | 39.5 Megapixels | |
| Image Resolution | 7 264 x 5 440 pixels | |
| Pixel Pitch | 6.06 μm | |
| Pixel Density | 2.72 MP/cm2 | |
| Moiré control | no AA filter | |
| Movie Capability | no Video | |
| ISO Setting | 100 - 1 600 ISO | |
| Image Processor | PRIME II | |
| DXO Sensor Quality (score) | 82 | |
| DXO Color Depth (bits) | 24.6 | |
| DXO Dynamic Range (EV) | 12.6 | |
| DXO Low Light (ISO) | 1262 | |
| Screen Specs | ||
| Viewfinder Type | Optical viewfinder | |
| Viewfinder Field of View | 98% | |
| Viewfinder Magnification | 0.78x | |
| Top-Level Screen | Control Panel | |
| LCD Size | 3.0 inch | |
| LCD Resolution | 921k dots | |
| LCD Attachment | Fixed screen | |
| Touch Input | No touchscreen | |
| Shooting Specs | ||
| Focus System | Phase-detect AF | |
| Manual Focusing Aid | no Peaking Feature | |
| Maximum Shutter Speed | 1/4000s | |
| Continuous Shooting | 1.1 shutter flaps/s | |
| Shutter Life Expectancy | 50 000 actuations | |
| Silent Shooting | no E-Shutter | |
| Time Lapse Photography | Intervalometer Built-in | |
| Fill Flash | no On-Board Flash | |
| Storage Medium | SDXC cards | |
| Single or Dual Card Slots | Dual card slots | |
| UHS card support | no | |
| Connectivity Specs | ||
| External Flash | Hotshoe | |
| Studio Flash | PC Sync socket | |
| USB Connector | USB 2.0 | |
| HDMI Port | no HDMI | |
| Wifi Support | no Wifi | |
| Body Specs | ||
| Environmental Sealing | Weathersealed body | |
| Battery Type | D-LI90 power pack | |
| Battery Life (CIPA) | 800 shots per charge | |
| Body Dimensions |
156 x 117 x 119 mm (6.1 x 4.6 x 4.7 in) |
|
| Camera Weight | 1 480 g (52.2 oz) | |
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