How do the Pentax 645, the Pentax 645N, and the Pentax 645N II differ?
| Pentax 645 | Pentax 645N | Pentax 645N II | |
|---|---|---|---|
| Camera type | SLR camera | SLR camera | SLR camera |
| Exposure format | 4.5 x 6 cm | 4.5 x 6 cm | 4.5 x 6 cm |
| Exposure area | 41.5 x 56 mm | 41.5 x 56 mm | 41.5 x 56 mm |
| Lens mount | Pentax 645 A-Mount | Pentax 645 AF, Pentax 645 A-Mount | Pentax 645 AF, Pentax 645 A-Mount |
| Focus | manual | automatic | automatic |
| Common exposure modes | Yes (center-weighted) | Yes (center-weighted, spot) | Yes (center-weighted, spot) |
| Built-in light meter | Yes | Yes | Yes |
| Metering range | EV 3 to EV 19 | EV 2 to EV 21 | EV 2 to EV 21 |
| Exposure compensation | +3 to -3 | +3 to -3 in 1/3 steps | +3.3 to -3.3 in 1/3 steps |
| Exposure lock | No | Yes | Yes |
| ISO range | ISO 6 to ISO 6400 | ISO 12 to ISO 6400 | ISO 12 to ISO 6400 |
| Pentax 645 | Pentax 645N | Pentax 645N II | |
| Shutter type | Electronically controlled focal-plane shutter | Electronically controlled focal-plane shutter | Electronically controlled focal-plane shutter |
| Shutter speeds | 1/1000 s to 15 s, Bulb | 1/1000 s to 4 s, Bulb | 1/1000 s to 6 s, Bulb |
| Multiple exposure | Yes | Yes | Yes |
| Mirror lock-up | No | No | Yes |
| Film format | 120, 220, 70 mm | 120, 220, 70 mm | 120, 220, 70 mm |
| Film transport | automatic | automatic | automatic |
| Viewfinder | Standard focusing screen with split-image indicator and microprism ring | Standard focusing screen with split-image indicator and microprism ring | Standard focusing screen with split-image indicator and microprism ring |
| Viewfinder coverage | 92% vertical, 93% horizontal | 92% vertical, 93% horizontal | 92% vertical, 93% horizontal |
| Diopter adjustment | -5 to +2 dpt. | -3.5 to +1.5 dpt. | -3.5 to +1.5 dpt. |
| Self-timer | Yes | Yes | Yes |
| Cable release | Yes | Yes | Yes |
| Tripod mount | Yes | Yes | Yes |
| Pentax 645 | Pentax 645N | Pentax 645N II | |
| Dimensions | 145.4 (W) x 109 (H) x 116.5 (D) mm | 147 (W) x 109 (H) x 117 (D) mm | 147 (W) x 109 (H) x 117 (D) mm |
| Weight | 1284 grams | 1280 grams | 1280 grams |
The Pentax 645, the Pentax 645N, and the Pentax 645N II are three models of SLR cameras that differ in some aspects. One of the main differences is the focus mode: the Pentax 645 has manual focus, while the Pentax 645N and the Pentax 645N II both have autofocus.
The exposure programs also vary: the Pentax 645 has only a center-weighted exposure program, while the Pentax 645N and the Pentax 645N II additionally offer a spot exposure program. Another difference is exposure compensation: while the Pentax 645 offers compensation from +3 to -3, the other two models allow finer adjustment from +3 to -3.3 in 1/3 steps. The Pentax 645N II also has an improved mirror lock-up compared to the other two models.
All three cameras use the 4.5 x 6 cm exposure format and have a Pentax 645 A-Mount lens mount. Of course, autofocus lenses can only be used with the two models that have this function.

All three models have a self-timer, a cable release, and a tripod socket. The self-timer allows the photographer to take a picture of themselves or group shots without needing another photographer. The cable release allows the photographer to trigger the camera without touching it, which is especially useful for long exposures to avoid blur. The tripod socket allows the camera to be securely attached to a tripod for shake-free shots.
In terms of size and weight, the models differ only slightly. The Pentax 645 is the smallest and lightest camera in the series at 145.4 (W) x 109 (H) x 116.5 (D) mm, weighing 1284 grams. The Pentax 645N and the Pentax 645N II are slightly larger at 147 (W) x 109 (H) x 117 (D) mm and weigh almost the same as the first model at 1280 grams. The differences in size and weight are minimal and should not be a decisive factor when choosing the camera.





