Compatibility of Old Pentax 645 SLR Lenses with Pentax DSLR Cameras
Many photographers and film enthusiasts are curious about the compatibility of their old Pentax 645 SLR lenses with modern Pentax DSLR cameras. This article aims to clarify the technical aspects and potential solutions to enable users to take advantage of their classic lenses with modern equipment.
Understanding the Compatibility Issue
Pentax 645 SLR lenses are designed for medium format film cameras, which have a significantly larger sensor size compared to the standard 35mm film. The Pentax DSLR cameras, however, come with sensors that are either half the size of a full-frame 35mm sensor or full-frame itself. This size difference presents a challenge in direct compatibility.
Solutions for Compatibility
One effective solution is the use of adapters that can allow the older 645 lenses to work with modern Pentax DSLR cameras. An adapter like the Fotodiox RhinoCam can be a viable option. This adapter not only connects the lens to the camera but also allows for lens shifting, a technique that is particularly useful for capturing panoramic images or highly detailed landscapes.
Advantages of Using a Fotodiox RhinoCam Adapter
Lens Shifting: The adapter facilitates lens shifting, enabling the creation of images with a larger "circle" coverage, which can then be stitched together to form a high-resolution image. Image Stitching: With the aid of image stitching software, multiple images taken from different angles can be blended into a single high-resolution image. Tools like Microsoft Research Image Compositor are available for this purpose, offering a free and effective solution. Megapixel Multiplication: By combining multiple high-resolution images, the effective megapixel count of the final stitched image can greatly increase. For example, using four 20MP images can result in an 80MP image, depending on the overlap of the images.Best Imaging Conditions for This Technique
This technique is particularly well-suited for landscapes and other stationary subjects that can be sufficiently stable for stitching. It is an advanced technique that requires a tripod for stability and meticulous attention to detail.
Alternative Solutions
Another option is to use older K-mount lenses directly with the DSLR camera, provided they have a bayonet to M42 screw fit adapter. This adapter can enable the use of manual focus lenses, which are often highly rated for their quality and can be purchased at reasonable prices. However, it is important to note that these lenses will not work in auto or program modes due to the manual nature of the lenses.
Cost and Considerations
The cost of the Fotodiox RhinoCam adapter is relatively high, often in the range of $200. On the other hand, adapting older K-mount lenses to M42 screw fit can be a more affordable solution for photographers who are looking to preserve the quality of their vintage lenses while using modern cameras.
Conclusion
In summary, while there are challenges in directly using Pentax 645 SLR lenses with modern Pentax DSLR cameras, various solutions exist to enable compatibility. Whether through the use of specialized adapters like the Fotodiox RhinoCam or by adaption of older lenses, photographers can continue to use their beloved film lenses with contemporary digital technology.