Pentax-DA 1.4x AW AF Rear Converter
Specifications
The official specifications for the Pentax-DA 1.4x teleconverter are as follows:
| Engraved Name | HD Pentax-DA 1.4x AW AF Rear Converter |
| Optical Design | 4 elements in 3 groups |
| Dimensions (D x L) | 65 x 20mm (2 9/16 x 25/32 in.) |
| Weight | 126g (4.4 oz) |
| Magnification | 1.4x |
| Light Loss | 1 stop |
| Mount | Pentax KAF2 |
| Weather Sealing | Yes |
| Lens Coating | HD Coating |
| Included Accessories | Soft case (DA 70mm Limited case), body mount cap, lens mount cap |
| Retail Price | $599.95 (USA) |
Camera Compatibility
The teleconverter officially supports the following Pentax camera models:
- K-3
- K-50
- K-500
- K-30
- K-5 II
- K-5 IIs
- K-5
- K-01
- K-7
- K-r
- Any K-mount DSLR launched after 2013
For the cameras explicity listed above, a firmware update is required for full teleconverter compatibility.
Older DSLR models, such as the K-x, K10D, and *ist D series can still be used with the teleconverter; we will discuss this later in the review.
Lens Compatibility
Lenses must be F4 or faster for full autofocus compatibility. Slower lenses (F5.6, F5.8) can be used, but phase detect autofocus could be unreliable in which case contrast detect autofocus (live view) is recommended.
Curiously, according to Pentax the SMC Pentax-DA 17-70mm F4 lens may not properly acquire focus in contrast detect mode (live view), here phase detect (viewfinder) should be used when the teleconverter is mounted.
The following lenses are not supported according to Pentax; using these lenses with the converter will damage the lens or converter:
- SMC Pentax-DA 15mm F4 ED AL Limited
- HD Pentax-DA 15mm F4 ED AL Limited
- SMC Pentax-DA 21mm F3.2 AL Limited
- HD Pentax-DA 21mm F3.2 AL Limited
- SMC Pentax-DA 40mm F2.8 XS
All other current lenses (as of March 2014) can be used with these caveats:
- SMC Pentax-DA* 55mm F1.4: The largest usable aperture with converter is F2.4 (the same holds for the F and FA 50mm F1.4 lenses as per our tests)
- SMC Pentax-DA 17-70mm F4: Contrast detect AF is unreliable, use phase detect
- HD Pentax-DA 560mm F5.6: phase detect autofocus may be unreliable, use contrast detect
- SMC and HD Pentax-DA 55-300mm F4-5.8: phase detect autofocus may be unreliable when zoomed in, use contrast detect
As the 1.4x teleconverter doesn't have a protruding optical element, it is compatible with a wider variety of lenses than teleconverters offered by competing brands, such as the Nikon 1.4x teleconverter which only supports longer lenses.
