The MonsterAdapter LA-KE1 has been around for a while but DPR posted a very in-depth review of the capabilities of the adapter that you can read here. In short, you won’t get native performance out of the adapter and it won’t support every last lens, but it is good enough to take advantage of some excellent Pentax glass. Below are some excerpts:
If you want to use your Pentax lenses on Sony E-mount bodies without losing autofocus, the MonsterAdapter LA-KE1 is basically the only game in town… While its performance will vary depending upon your chosen lenses and camera bodies, we found the LA-KE1 adapter to yield rather lesser AF performance than is natively available from Pentax bodies… Whether you’re hooked on the look those lenses provide or just want to delay buying their replacements for as long as possible, the MonsterAdapter LA-KE1 is definitely worthy of consideration.
Pro:
- Pentax glass on Sony E-mount without losing AF and aperture control
- Relatively small and compact
- Solid, durable build
- Works with both single and continuous AF
- Works with screw-drive and in-lens AF motors, even for precision operations like remote-controlled focus stacking
- Works with mechanical and electronic aperture control
- Works with in-body image stabilization
Con:
- Quite pricey
- No weather sealing
- Control feel isn’t very premium
- Negates the size advantage of mirrorless cameras
- Slower AF than with a Pentax body
- No video autofocus
MonsterAdapter LA-KE1: B&H Photo