This lens is the widest rectilinear lens available for Pentax 6X7/67 system with the angle of coverage and perspective of 22mm lens on a 35mm camera. It is much smaller, lighter and more compact than any of the 55mm. This lens is a quite unique lens not only Pentax 6X7/67 system but in comparance to other ultra wide-angle lenses that cover 6X7. The most closest lens is rangefinder Mamiya 7 1:4.5 43mm which is the great performer but a bit darker and has serious light fall off from the center to the corners. Thus it requires using of dedicated center filter in many cases. The widest Mamiya RB/RZ67 lens is only 50mm and is slightly darker by 1/2 EV.
This is one of few lenses that have special clip on the rear side to hold slip-in gelatin filters.
There are two variants of the same lens were produced. It is exactly the same lens. The difference is only in the name engraved on the lens, focusing and aperture rings finishing.
|SMC PENTAX-6X7 1:4 45mm||486g||1980|
|SMC PENTAX 67 1:4 45mm||486g||1989|
The lens accepts special 6X7 bayonet filters as well as screw-in filters of 82mm size. It is also has a special clip on the rear side to mount slip-in gelatin filters. Using such filters allows to prevent result image from vignetting.
The diaphragm unit of the lens has 8 aperture blades. Each of the images below shows aperture consequentially stopping down by 1EV.
The early version of the original dedicated hood has "6X7" sign and lens parameters engraved on the top. Later Pentax has changed it to "PH-SB" model name. These hoods are the same. They both have very good internal blackening preventing lens from reflections good enough.
A cheap round metal hood can be found on eBay for just $4. It is a good solution because original dedicated hood costs around $60 for the hood with case. In other hand the orginal hood has better internal blackening that the cheap one lacks.
- Focal length: 45mm
- 35mm equivalent: 24mm
- Optical formula: 9 elements, 8 groups
- Field of view: 89°
- Horizontal: 76°
- Mount: inner bayonet
- Diaphragm: automatic
- Aperture range: 4 ~ 22
- Aperture blades: 8
- Close distance: 37cm
- Magnification: 0.17×
- Picture area: 324×412mm
- Filter: 82mm - screw-in and bayonet
- Hood: PH-SB 82mm
- Case: S90-100
- Dimensions: 91.5×57.5mm